Saturday, April 13, 2019

Evolution of color vision to detect social info: Dichromats may be less accurate at detecting others’ emotional states; dichromats may also display weaker approach/avoidance behavior toward healthy/sick individuals

Social Perception of Facial Color Appearance for Human Trichromatic Versus Dichromatic Color Vision. Christopher A. Thorstenson, Adam D. Pazda, Andrew J. Elliot. Personality and Social Psychology Bulletin, April 13, 2019. https://doi.org/10.1177/0146167219841641

Abstract: Typical human color vision is trichromatic, on the basis that we have three distinct classes of photoreceptors. A recent evolutionary account posits that trichromacy facilitates detecting subtle skin color changes to better distinguish important social states related to proceptivity, health, and emotion in others. Across two experiments, we manipulated the facial color appearance of images consistent with a skin blood perfusion response and asked participants to evaluate the perceived attractiveness, health, and anger of the face (trichromatic condition). We additionally simulated what these faces would look like for three dichromatic conditions (protanopia, deuteranopia, tritanopia). The results demonstrated that flushed (relative to baseline) faces were perceived as more attractive, healthy, and angry in the trichromatic and tritanopia conditions, but not in the protanopia and deuteranopia conditions. The results provide empirical support for the social perception account of trichromatic color vision evolution and lead to systematic predictions of social perception based on ecological social perception theory.

Keywords: trichromatic, color vision, social perception, evolution, face color


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The human face is a wellspring of social information; we can make rapid judgments about a wide range of social characteristics (e.g., sex, race, age, attractiveness, health, emotion) based on only a brief exposure to facial stimuli (Weisbuch & Ambady, 2011). Although a majority of traditional social psychological research has focused on assessing how these judgments influence downstream phenomena (e.g., stereotyping and behavior), only recently have researchers focused on elucidating the lower level perceptual mechanisms that produce these judgments in the first place (Freeman & Ambady, 2011; Oosterhof & Todorov, 2008). An emerging line of research has demonstrated that one such perceptual mechanism that can independently influence a range of social judgments is facial color appearance (for reviews, see (Rowland & Burriss, 2017; Stephen & Perrett, 2015; Thorstenson, 2018). This work suggests that human color vision plays a key role in social perception processes. In the current article, we briefly review theoretical accounts of human color vision evolution, including a recent account driven by social evolutionary considerations. We then overview the existing literature on the role of facial color appearance in the expression and perception of social characteristics (i.e., attractiveness, health, and emotion), grounded in an ecological theory of social perception (Zebrowitz-McArthur & Baron, 1983). Finally, we report two experiments that provide an empirical test of the social evolutionary account of human color vision.

Typical human (and most primate species) color vision is considered trichromatic, meaning we possess three distinct classes of wavelength-sensitive photoreceptive cells called cone photorecepters, or cones, that allow us to discriminate chromatic colors across the visible spectrum. These cones are distinguished as short wavelength (S; with peak sensitivity at ~430 nm), medium wavelength (M; with peak sensitivity at ~535 nm), and long wavelength (L; with peak sensitivity at ~562 nm; Jacobs & Deegan, 1999). Whereas most mammalian species possess dichromacy (having one S cone and one M/L cone), trichromacy in humans and most nonhuman primate species evolved when the older M/L cone opsin gene duplicated and diverged into two separate M and L cones (Dulai, von Dornum, Mollon, & Hunt, 1999).

The functional significance of trichromacy evolution is currently under debate. A popular account suggests that trichromacy was selected to aid primates in foraging by facilitating the detection of ripe fruit against green leaves (Allen, 1879; Lucas et al., 2003; Mollon, 1989; Osorio & Vorobyev, 1996; Surridge & Mundy, 2002). While there is support demonstrated for this hypothesis (Bunce, Isbell, Grote, & Jacobs, 2011; Caine & Mundy, 2000; Melin et al., 2009; Osorio, Smith, Vorobyev, & Buchanan-Smith, 2004; Regan et al., 2001; Smith, Buchanan-Smith, Surridge, & Mundy, 2003; Smith, Buchanan-Smith, Surridge, Osorio, & Mundy, 2003; Sumner & Mollon, 2000; Vorobyev, 2004), some ecological studies do not observe a benefit of trichromacy on foraging behavior (Hiramatsu et al., 2008; Vogel, Neitz, & Dominy, 2007). Other theoretical accounts of color vision variation in primates that have received less empirical attention include camouflage detection, predation detection, and nocturnal versus diurnal activity (see Kawamura & Melin, 2017, for a comprehensive review).

Alternatively, a more recent functional account posits that trichromacy may have been selected by social evolutionary pressures (Changizi, 2010; Changizi & Shimojo, 2011; Changizi, Zhang, & Shimojo, 2006). Specifically, this account suggests that the divergence of M and L cones allows for the optimal detection of socially relevant skin color appearance fluctuations in others. Changizi and colleagues (2006) note that changes in dermal hemoglobin oxygenation and concentration lead to predictable changes in the spectral reflectance (and consequently visible color) of skin. Increases in hemoglobin oxygenation heighten relative L-cone to M-cone activation, resulting in redder skin appearance (while decreases in hemoglobin oxygenation produce the opposite, resulting in greener skin appearance). Increases in hemoglobin concentration tend to increase M- and L-cone activation relative to the S cone, resulting in blue skin appearance, whereas decreases in hemoglobin concentration produce the opposite, resulting in yellow skin appearance (see also Thorstenson, 2018 for a review). Importantly, Changizi and colleagues (2006) demonstrated that M- and L-cone sensitivities in trichromats are situated in the visible spectrum such that they are able to optimally detect these skin color appearance fluctuations. This corre-spondence, between the spectral sensitivity of trichromatic photoreceptors and spectral fluctuations of skin enduring transient hemoglobin changes, presumably enables particu-lar sensitivity to discriminate socially relevant physiologi-cal conditions (e.g., emotional states, sexual signals, and threat displays). It has also been noted that trichromatic primates tend to be bare-faced, allowing rapid access to visual skin color appearance modulations. See Figure 1 for an illustration of the spectral characteristics of human skin and trichromatic photoreceptors. While there is some recent work supporting this hypothesis for viewing nonhuman pri-mate targets (Hiramatsu, Melin, Allen, Dubuc, & Higham, 2017) research in this area is still sparse and has yet to be conducted using human targets.

An ecological theory of social perception holds that social perception processes serve an adaptive function (Zebrowitz, Bronstad, & Montepare, 2011; Zebrowitz-McArthur & Baron, 1983). Perception facilitates goal attainment and species propagation by informing behavior (Gibson, 1979). This ecological approach to social perception assumes that (a) the external environment provides information to guide biologically and socially functional behaviors, and (b) the success-ful transfer of this information relies on a compatibility between a signal (stimulus information) and the perceiver (perceptual system). In the current investigation, we focus on the stimulus information (facial color expression) and the perceptual system (facial color perception) involved in social processes related to evaluation of attractiveness, health, and emotion. We chose to focus on these evaluations because they represent interpersonally important perceptions that shape social interaction and decision making. For instance, perceptions of attractiveness and health guide mating deci-sions because they provide an indicator of overall mate quality and reproductive potential (Etcoff, 1999; Perrett, 2010; Rhodes et al., 2007; Weeden & Sabini, 2005). Similarly, perceptions of emotion (e.g., anger) inform situational context (e.g., dominance, hostility) and guide behavior (e.g., avoidance; Marsh, Adams, & Kleck, 2005).

Indeed there is evidence that skin color appearance subtly undergoes change as an inevitable consequence of socially relevant states. In nonhuman primates, female skin color appearance becomes redder throughout the ovulatory ycle, when sexual cues afford the most significant reproductive consequences (Bielert, Girolami, & Jowell, 1989; Deschner, Heistermann, Hodges, & Boesch, 2004; Dixson, 1983; Gerald, 2003; Setchell & Wickings, 2004; Setchell, Wickings, & Knapp, 2006; Waitt, Gerald, Little, & Kraiselburd, 2006). Skin color appearance in male nonhu-man primates also influences female preferences by signal-ing elevated testosterone (Rhodes et al., 1997; Waitt et al., 2003). In addition, there is evidence that the same skin color appearance modulations occur in human females (Burriss et al., 2015; Edwards & Duntley, 1949; B. C. Jones et al., 2015; McGuiness, 1961; Oberzaucher et al., 2012; Snell & Turner, 1966; van den Berghe & Frost, 1986) and possibly males (due to elevated testosterone; Miller & Maner, 2010). Furthermore, skin color appearance undergoes change as a consequence of physiological states related to health, includ-ing skin vascularization (Changizi & Shimojo, 2011; Charkoudian, 2003; Henderson et al., 2017; Panza, Quyyumi, Brush, & Epstein, 1990; Ponsonby, Dwyer, & Couper, 1997; Sibenge & Gawkrodger, 1992; Wilkin, 1994), bilirubin (Knudsen & Brodersen, 1989), melanin (Stamatas, Zmudzka, Kollias, & Beer, 2004; Zonios, Bykowski, & Kollias, 2001) and carotenoids (Alaluf, Heinrich, Stahl, Tronnier, & Wiseman, 2002; Coetzee & Perrett, 2014; Tan, Graf, Mitra, & Stephen, 2015, 2017; Whitehead, Re, Xiao, Ozakinci, & Perrett, 2012). Finally, there is a sizable litera-ture examining the physiological correlates of experiencing various emotion states, which can then be used to predict how skin color appearance likely changes with respect to these emotions (see Thorstenson, 2018; Thorstenson, Elliot, Pazda, Perrett, & Xiao, 2018, for reviews).



Discussion: [...] Although the prevalence of dichromatic indi-viduals in the general population is quite low (between 2% and 8% of males and approximately 0.4% of females have a red-green color deficiency, and approximately 0.002% of both males and females have a blue-yellow color defi-ciency; Birch, 2012; Simunovic, 2010), these findings raise the possibility that certain color deficiencies exhibit less informed decision making in the social domain as a consequence of systematic misperception. For example, dichromats may be less accurate at detecting others’ emo-tional states, especially when facial expressions can be controlled (e.g., an angry person can maintain a neutral expression, but will still experience facial flushing). This may have problematic behavioral implications, such as failing to avoid someone with a flaring temper and a straight face. Dichromats may also display weaker approach/avoidance behavior toward healthy/sick individuals, and in the medical domain, it has been noted that dichromatic clinicians have significant difficulty in assess-ing clinically relevant skin color modulations (Changizi & Rio, 2010). Although empirical investigations into these possibilities would be difficult due to the relatively low prevalence of dichromats, they would be extremely informative nonetheless. [...]

The proportion of male students who reported having sexual intercourse before age 13 years varied from 5% (San Francisco) to 25% (Memphis, TN); elevated rates among black and Hispanic males

Prevalence of Sexual Initiation Before Age 13 Years Among Male Adolescents and Young Adults in the United States. Laura D. Lindberg, Isaac Maddow-Zimet, Arik V. Marcell. JAMA Pediatr. April 8, 2019. doi:10.1001/jamapediatrics.2019.0458

Key Points

Question: Does the prevalence of sexual initiation before age 13 years among males in the United States vary by race/ethnicity, location, and socioeconomic status?

Findings: This cross-sectional study of 19 916 male high school students and 7739 males aged 15 to 24 years found substantial variation in the rates of sexual onset before 13 years of age across metropolitan areas and by race/ethnicity, with rates as high as 28% among non-Hispanic black males in Memphis, Tennessee.

Meaning: Variation in timing of sexual initiation before age 13 years may have implications for the provision of early, inclusive, and comprehensive sex education as well as sexual and reproductive health care to male children and adolescents.

Abstract
Importance: Despite similar sexual activity rates among male and female adolescents, males are more likely to have their first sexual intercourse before age 13 years. The developmental needs and pathways to healthy trajectories for young males remain unknown.

Objective: To examine the prevalence of sexual intercourse before age 13 years among male adolescents; the variation by race/ethnicity, location, and maternal educational level; and the wantedness of this first sexual experience.

Design, Setting, and Participants: This cross-sectional analysis was conducted from September 2017 to June 2018, using pooled 2011, 2013, and 2015 data from the school-based Youth Risk Behavior Surveillance System (YRBSS) and the 2006 to 2015 data of males aged 15 to 24 years from the household-based National Survey of Family Growth (NSFG). The percentage of males reporting sexual onset before age 13 years was estimated using survey-weighted logistic regression to test for differences by race/ethnicity within each national survey and within metropolitan areas (for YRBSS, high school and middle school samples). Among NSFG survey respondents, differences in wantedness of first sexual intercourse by age at first sexual intercourse were examined, along with the associations between sexual initiation and socioeconomic covariates.

Main Outcomes and Measures: Sexual onset before age 13 years.

Results: Data from a total of 19 916 male high school students (from YRBSS) and 7739 males aged 15 to 24 years (from NSFG) were included in the analysis. The sample was largely composed of non-Hispanic white males: 8789 (57.1%) from the YRBSS and 3737 (58.0%) from the NSFG. Sexual onset before age 13 years was reported nationally by 7.6% (95% CI, 6.8%-8.4%) of male high school students and 3.6% (95% CI, 3.0%-4.2%) of males aged 15 to 24 years. The proportion of male students who reported having sexual intercourse before age 13 years varied across metropolitan sites, from 5% (95% CI, 4%-7%) in San Francisco, California, to 25% (95% CI, 23%-28%) in Memphis, Tennessee, with elevated rates among non-Hispanic black and Hispanic males in most metropolitan areas. In the NSFG data set, respondents whose mothers had a college degree or higher educational level were statistically significantly less likely (OR, 0.31; 95% CI, 0.19-0.49) to report having sexual intercourse before age 13 years compared with those whose mothers did not have a college degree. Among males who reported having their first sexual experience before age 13 years, 8.5% (95% CI, 3.8%-17.8%) described their first sexual intercourse as unwanted.

Conclusions and Relevance: Rates of sexual onset before age 13 years among young males varied by race/ethnicity, location, and maternal educational level, presenting important implications for the provision of early, inclusive, and comprehensive sex education and sexual and reproductive health care to male children and adolescents.

Introduction

First sexual intercourse marks an important transition in an individual’s life,1 and early adolescence is a critical developmental period when experimentation with sexual feelings and behaviors often begins.2,3 During these formative years, expectations to adhere to gender roles and norms intensify. The Centers for Disease Control and Prevention’s Youth Risk Behavior Surveillance System (YRBSS) tracks sexual intercourse before age 13 years as a core surveillance metric and finds that males are more than twice as likely as females to experience first sexual intercourse before age 13 years.4 Sex education guidelines recommend providing children with comprehensive sex education starting at least by kindergarten, and clinical care guidelines recommend clinicians set time alone with young patients to address confidential care inclusive of sexual health starting during early adolescence.5,6 However, most males start having sex before receiving sex education, and the quality of sexual health care delivery to male adolescents is poor.7-9

Estimates of young males’ transition to first sexual intercourse do not examine the prevalence of sexual activity in early adolescence across the intersecting demographics of sex, race/ethnicity, and location, likely missing important variations.10-12 A nationally representative study of sexual behavior reports it as “rare” among those 12 years and younger.13 Yet this conclusion may miss subgroups of males for whom sexual initiation before age 13 years is more common. Given the higher prevalence of first sexual intercourse before age 13 years among males compared with females, understanding the variation in the timing of sexual onset among adolescent males in the United States is critical to supporting their healthy sexual development.

Males’ experiences with regard to emergent manhood and sexuality are shaped by dimensions of masculinity, race/ethnicity, socioeconomic status, and location. Broad cultural scripts about masculinity and sex hold that men should start having sex early and have sex often.14 For young men of color, particularly black males, racist stereotypes of hypermasculinity may also contribute to expectations of early sexual initiation.15-17 Yet research highlights that males in early and middle adolescence do not necessarily follow such scripts and a later transition to first sexual intercourse may be valued.18-22 Understanding males’ wantedness of the sexual experience may be particularly important for interpreting early sexual activity.23,24

Aspects of adolescents’ communities may also be factors in the transition to first sexual intercourse.25-28 Cultural norms and values associated with masculinity may differ across communities.29 Some studies have found differences in the timing of first sexual intercourse between urban and rural settings.30,31 Even across specific urban areas, young men’s experiences may vary.

The current study examined the prevalence of sexual initiation before age 13 years among adolescent males in the United States and the variation in the timing of their sexual initiation by race/ethnicity, location, and maternal educational level and by their characterization of the wantedness of this first sexual experience. Race/ethnicity, socioeconomic status, and location are not the only factors in the timing of first sexual intercourse, but they inform the context in which these experiences and other correlates occur. We used 2 complementary large-scale representative survey systems to assess the timing of sexual onset among adolescent males in the United States, examine key sociodemographic correlates, and consider how reporting issues may affect estimates.

Evidence from online dating sites suggests that most users behave strategically: they remain silent about their political attitudes, more willing to divulge their weight than their politics

From 2017: The Moderating Effects of Marriage Across Party Lines. Shanto Iyengar, Tobias Konitzer. 2017. https://pdfs.semanticscholar.org/a55b/50f3de44529ee301c662aa42fb244e4ab992.pdf

“The Democrats, wherever you find ’em – in the media, think tanks, don’t care whereyou find ’em – they’re being consumed by it, folks. Theyre literally being eaten alive withan irrational, raw hatred.” – Rush Limbaugh, May 10, 2017.

In the aftermath of the 2016 election, the American electorate is hyperpolarized. Animustoward the out party is at an historic high. For the first time on record, the most frequentlyregistered feeling thermometer score for the opposing party (e.g. Democrats’ rating of theRepublican Party and vice-versa) in the 2016 American National Election Study was at theminimum, i.e. zero. Other indicators are similarly skewed toward the extremes. PresidentTrump’s approval drops precipitously from 80 percent among Republicans to under tenpercent for Democrats. Some six times as many Democrats than Republicans believe thatthe Trump campaign colluded with the Russians to sway the election (Washington Post Poll,April 26, 2017). Hostility directed at out groups is a fundamental barometer of group polarization. Classic studies on social distance (Bogardus, 1925), and the sense of social identity (Tajfel, 1970;Tajfel and Turner, 1979) have established that diverging sentiment for in- and out-groupmembers is inevitable. Group polarization defined in terms of differential affect for the inand out group occurs even when the basis for group affiliation is trivial and completelyunrelated to group interests.In the context of American politics, affective polarization deriving from political partyaffiliation is well documented, in stark contrast to ideological polarization, where the evidenceis mixed (compare Abramowitz 2010 with Fiorina, Abrams and Pope 2005). As for partisanaffect, data from the American National Election Surveys dating to the mid-1980s showsthat Democrats and Republicans not only increasingly dislike the opposing party, but alsoimpute negative qualities to its supporters (Iyengar, Sood and Lelkes, 2012).Out-group prejudice based on party identity exceeds the comparable bias directed atracial, religious, or cultural out groups (Muste, 2014; Iyengar and Westwood, 2015). Partisan2 affect has strengthened to the point where party identity is now a litmus test for interpersonalattraction. People prefer to associate with fellow partisans and are less trusting of partisan opponents (Iyengar and Westwood, 2015; Westwood et al., 2017). The most vivid evidence of increased social distance across the party divide concerns inter-party marriage. In the early 1960s, the percentage of partisans expressing concern over the prospect of their son or daughter marrying someone from the opposition party was in the single digits, but some forty-five years later it had risen to more than twenty-five percent (Iyengar, Sood and Lelkes,2012). Data from surveys of married couples, online dating sites, and national voter files confirmthat partisanship has become a key attribute underlying the selection of long-term partners (Huber and Malhotra, 2017; Iyengar, Konitzer and Tedin, 2017). Among recently marriedcouples in 1973, only 54 percent shared the same party affiliation. Forty years later, partisan agreement among this group had risen to 74 percent (Iyengar, Konitzer and Tedin, 2017).Survey results standing alone may not be the most meaningful measure of increasingpartisan animus. The expression of hostility based on partisanship is not subject to thesame social taboos as hostility based on other salient social divides (racial, religious, orethnic). Instead, hostility directed at the out party is deemed acceptable, even appropriate.Therefore, survey data could artificially elevate the significance of the partisan divide overother significant cleavages. But, importantly, there is considerable evidence of increasedpartisan animus outside the survey realm; this evidence is not subject to normative, consciousrestraints based on political correctness. Using a version of the Implicit Association Test,Iyengar and Westwood (2015) demonstrated that implicit bias directed at the out partyexceeded comparable bias based on race. They also showed that behavioral discriminationagainst partisan opponents in a variety of contexts exceeded discrimination based on othergroup cues, most notably, race. What explains the dramatic increase in affective polarization over the past few decades?3

The period in question (1985-2015) coincides with any number of major societal changes,including the vastly increased ethnic and cultural diversity of the population, the migration ofwhites from urban areas to the suburbs, the emergence of the South as a staunch Republicanregion, and the politicization of evangelical Christians. One possible explanation, sometimesreferred to as ”sorting,” is the increasing convergence of multiple salient social identities which reinforce each other. In other words, Democrats and Republicans differ not only int heir politics, but also in their ethnic, religious, gender, cultural, and regional identities.Sorting leads to overlapping group memberships and the increasing partisan homogeneity of primary and secondary groups is a further contributor to polarization. Family and kinship networks – key influences over the development of political attitudes – provide few opportunities for meaningful and long-term personal contact across party lines. As we notebelow, even at the level of secondary groups, defined on the basis of occupation, religion, orplace of residence, partisan homophily is extensive (for evidence on occupational similarity inpartisan affiliation, see Bonica, Chilton, and Sen 2016; the geographic sorting of the nation into Republican and Democratic enclaves is documented most recently in Chen and Cottrell2016 and Chen, Rodden et al. 2013.We investigate the role of interpersonal relations as a potential contributor to partisanpolarization. We focus on the family, the most important agent of political socialization.Comparing surveys of spouses conducted in the 1960s, the 1990s and the current era, wedemonstrate that over time, spousal disagreement – although clearly becoming less frequent– can act as a brake on polarization by fostering less hostile attitudes toward partisan opponents. The more heterogeneous the household, the less polarized the individual members.We replicate these survey findings a secondary analysis of a set of 2015 and 2016 field experiments that targeted registered voters in multiple states. Participants in these experiments completed surveys that included feeling thermometers and other measures of partisan affect. Because the surveys sampled multiple family members living at the same address, we can4 investigate the effects of household agreement on partisan affect. In fact, the data from these field studies converge with the surveys of spouses; mixed-party households are significantly less polarized.


Discussion

In our experience, it is unusual to observe differences of this scale in the behavioralsciences. In several instances, the order of magnitude of the difference in polarization between similar and dissimilar family pairs exceeded 200 percent! Even more unusual is thefact that our results survived multiple replications spanning different research designs, elec-toral contexts, and survey indicators of partisan affect. While we acknowledge the causalthreat posed by selection effects, i.e. potential spouses with polarized attitudes selectinginto homogeneous marriages, the matching analysis does little to bolster this alternativeexplanation.9In total, the story line is unmistakable; political disagreement within familyrelations discourages extreme evaluations of in and out groups, thus alleviating polarization.Of course, documenting the powerful effects of family diversity on partisan affect begsthe question of what exactly is the mechanism through which exposure to disagreementmoderates individuals’ evaluations of the parties. One possibility is that domestic tranquilityrequires the expression of opinions that respect the positions of significant others, makingindividuals more tolerant and accepting of disagreement. Alternatively, as suggested by theclassic “contact” hypothesis (Allport, 1954; Pettigrew, 1998, 1997), valued inter-personalrelations that cut across the party divide may serve to weaken negative stereotypes of theout group; for contrary evidence, however, see Enos (2014). Yet another possible mechanism,also suggested by previous research (Mutz, 2006), is that inter-personal contact heightensawareness of the values and arguments underlying the preferences of out party supporters,making the party appear less threatening. All these mediating mechanisms appear to becontingent on exposure to the opponent’s point of view; we would anticipate, accordingly,that the effects of family diversity on partisan evaluations will be enlarged when familymembers frequently converse about public affairs.While our results imply that cross-party family ties are a potential antidote to polariza-tion, it is important to keep in mind that this ”treatment” only impacts a relatively smallswath of American partisans. The most recent data on inter-marriage indicate that less9Although while matching might tackle the selection problem more appropriately then parametric re-gression analyses, we note that the identification assumption remains selection-on-observables.23 than twenty percent of partisans are exposed to disagreement. The likelihood that parti-sans’ children will diverge on political grounds is similarly remote; in a 2015 survey, 74.2percent of parent-offspring dyads agreed on their partisan affiliation (Iyengar, Konitzer andTedin, 2017). The critical question, therefore, concerns the ways in which society can lowerthe barriers to social exchange across the party divide.In theory, one solution to the problem of politically homogeneous networks is to weakenindividuals’ ability to signal their political affiliation. If all participants in the marriageor dating market were ”blind” to partisan affiliation, partner selection would be drivenprimarily by non-political attributes. Rational ”sellers” should deliberately conceal theirpolitical views when seeking out potential mates. In fact, the evidence from online datingsites suggests that most users of these sites behave strategically: they choose to remainsilent about their political attitudes. Research into the content of online daters’ personalprofiles shows that less than fifteen percent of online daters provided information abouttheir “political interests” and when they did reference politics in their personal profile, theyidentified themselves as “middle of the road” (Klofstad, McDermott and Hatemi, 2012). This same study shows, revealingly, that online daters are more willing to divulge their weightthan their political preferences.Online databases provide opportunities for people to sort into relationships on the basisof attributes extraneous to partisanship. Since some twenty percent of single individualsreport using online dating sites, technology might be a tool for dampening polarization.Yet, as Huber and Malhotra (2017) have recently demonstrated, individuals manage tounearth information about their prospective partner’s political views despite the lack oftransparency; so much so, that political ideology is the strongest predictor of successfulonline match making. The motivation to find a politically compatible mate is sufficient toovercome online daters’ lack of transparency about their politics.In closing, our results show that partisan attitudes are distinctly less polarized when close inter-personal ties are not based on the criterion of political similarity. For those seekingto reduce animus and conflict across party lines, it is important to design meeting placesor platforms on which people become less focused on questions of political identity as animportant basis for their inter-personal relations.

Under What Conditions Does Prosocial Spending Promote Happiness?

Lok, Iris, and Elizabeth W. Dunn. 2019. “Under What Conditions Does Prosocial Spending Promote Happiness?” PsyArXiv. April 12. doi:10.31234/osf.io/9bpg5

Abstract: Under what conditions does prosocial spending promote happiness? In a series of well-powered and pre-registered experiments, the present research revisited the role of impact, social connection, and perceived choice in maximizing the emotional benefits of spending money on others. In two exploratory studies, we found that happy (vs. less happy) prosocial spending experiences were marked by higher levels of impact, social connection and perceived choice (Study 1a and 1b). Consistent with these initial findings, three pre-registered studies revealed confirmed that spending money on others was particularly rewarding when people were able to see the difference their generosity made (Study 2); when they felt a sense of social connection to the person or cause they were helping (Study 3); and when they felt that the decision to help was freely chosen (Study 4). Together, our findings corroborate previous research on impact, social connection and perceived choice, and highlight the importance of considering these key variables when evaluating old and new evidence on prosocial spending on happinessthe emotional benefits of prosocial spending. In addition, our findings suggest that  the present work urges charitable organizations and policymakers should to review their current solicitation strategies and pay more attention to people’s sense of impact, connection and choice when seeking charitable donations.

Friday, April 12, 2019

How Many Words Do We Read Per Minute? Less than the numbers often cited in scientific and popular writings.

Brysbaert, Marc. 2019. “How Many Words Do We Read Per Minute? A Review and Meta-analysis of Reading Rate.” PsyArXiv. April 12. doi:10.31234/osf.io/xynwg

Abstract: Based on the analysis of 190 studies (17,887 participants), we estimate that the average silent reading rate for adults in English is 238 word per minute (wpm) for non-fiction and 260 wpm for fiction. The difference can be predicted by the length of the words, with longer words in non-fiction than in fiction. The estimates are lower than the numbers often cited in scientific and popular writings. The reasons for the overestimates are reviewed. Reading rates are lower for children, old adults, and readers with English as second language. The reading rates are in line with maximum listening speed and do not require the assumption of reading-specific language processing. The average oral reading rate (based on 77 studies and 5,965 participants) is 183 wpm. Within each group/task there are reliable individual differences, which are not yet fully understood. For silent reading of English fiction most adults fall in the range of 175 to 300 wpm; for fiction the range is 200 to 320 wpm. Reading rates in other languages can be predicted reasonably well be taking into account the number of words these languages require to convey the same message as in English.

The widely held assumption in philosophy & psychology that one purpose of human morality is to regulate social behavior is confirmed: the presence of another person increased moral values' importance

Yudkin, Daniel A., Ana P. Gantman, Wilhelm Hofmann, and Jordi Quoidbach. 2019. “Moral Values Gain Importance in the Presence of Others.” PsyArXiv. April 12. doi:10.31234/osf.io/tcq65

Abstract: A widely held assumption in philosophy and psychology is that the purpose of human morality is to regulate social behavior. Yet this premise has never been tested directly. We used a custom smartphone application to repeatedly record participants’ (N = 1,166) social context and the importance they afforded different moral values. Results showed moral values were rated more important when people were in the presence of others versus alone. This effect was robust to a series of potential confounds (demographics, time of day, mood) and was moderated by relationship type such that closer social relationships exerted stronger impact on moral evaluation than more distant. Furthermore, the effect of social proximity on moral evaluation was stronger for “binding” values than “individualizing” ones, suggesting the effect of social context differs according to value type. A randomized laboratory experiment confirmed that the mere physical presence of another person in the immediate environment increased the importance of moral values. Overall, these results demonstrate the contextual sensitivity of moral values and corroborate the view that morals play a social-regulatory role in human behavior.

Moral Values Gain Importance in the Presence of Others

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When we think about moral values, it is tempting to picture the philosopher in the armchair, postulating moral principles. Yet there is near consensus this is the wrong way to describe morality. Instead, research suggests the more accurate picture is that of two or more people, figuring out how to live and work together (i, ii, iii, iv, v).
The inherently social nature of morality suggests moral values may be more salient when people are in social contexts. Fitting this idea, classic research suggests the presence of others impacts behavior (vi). Other work shows that social situations increase egalitarian behavior (vii, viii), and the mere suggestion of an external observer can increase cooperation (ix, x, xi). Remarkably, however, the possibility that moral values gain importance in the presence of others has never been directly tested empirically. Answering this question would thus provide empirical validation to a foundational assumption in moral theory.
We sought tested this question using an app-based experience-sampling method (xii, xiii). By measuring the importance of moral values in people’s daily lives as well as their current social situations, this approach has the potential to obtain a more accurate picture of how context impacts moral evaluation. We also tested two additional hypotheses. First, past research suggests that people’s treatment of others varies according to their social distance to the self (xiv, xv). Accordingly, we tested whether the effect is moderated by social distance. Second, research shows morality can be divided into two types of values: “individualizing” (concerned with rights and freedoms), and “binding” (concerned with group harmony and cohesion) (xvi, xvii). Because the latter set is particularly important for social regulation (xviii) it is possible the importance of these values is especially sensitive to the presence of others (xix). Overall, our method presented an opportunity to put several influential theories of moral psychology to the test in a real-world setting.
The research was part of the “58 seconds” project (xx) approved by The Ethics Committee of ESADE Business School, Spain. European adults (N = 1,166, Mage = 35.7, SD = 11.1, 861 female, 305 male) were asked a series of questions (pulled from a larger pool) at random intervals over several months. Moral importance was assessed by averaging across responses of how important it was for participants to behave in accordance with values of care, fairness, loyalty, authority, and purity (0 – not at all; 100 – very) (17). Participants also indicated how happy they felt (0 – not at all; 100 – very), and who, if anyone, they were with. The analytic approach consisted of a series of multilevel analyses using the lme4 and lmerTest packages in R controlling for participants’ age and gender, hour of day, and day of week, with participant-level random intercepts (all scripts and materials at https://osf.io/4q8jg/).

Smartphone zombies! Pedestrians’ distracted walking as a function of their fear of missing out

Smartphone zombies! Pedestrians’ distracted walking as a function of their fear of missing out. Markus Appel et al. Journal of Environmental Psychology.
April 12 2019. https://doi.org/10.1016/j.jenvp.2019.04.003

Highlights
•    The motives for smartphone use while walking are not well understood.
•    We explore the Fear of Missing Out (FoMO) as a potential reason for this behavior.
•    FoMO predicts distracted walking regardless of participants' age or gender.
•    It further predicts pedestrians' virtual social interactions and dangerous incidents.

Abstract: Smartphone use while walking (i.e., being a smartphone zombie) has become a prevalent phenomenon in many ciies worldwide. Previous research shows that many pedestrians choose to interact with their phones as they walk around in cities, despite being aware that their behavior might be dangerous. To investigate potential reasons for the prevalence of distracted walking, the current study explores the construct Fear of Missing Out (FoMO) as a potential antecedent of pedestrians' smartphone use while walking. Hierarchical OLS and logistic regression analyses show that FoMO predicts distracted walking, the tendency to engage in virtual social interactions while walking, and dangerous traffic incidents—irrespective of participants’ age and gender. Virtual communication might serve as a compensation for real-world company, thus sidelining the need to traverse safely.

Partnered women blindly rated their partner's body odor as smelling sexier and less strong than the body odor of unknown males; body odor preference ratings appear to be driven by familiarity ratings

Do women love their partner's smell? Exploring women's preferences for and identification of male partner and non-partner body odor. Mehmet K. Mahmut, Richard J. Stevenson, Ian Stephen. Physiology & Behavior, Apr 12 2019. https://doi.org/10.1016/j.physbeh.2019.04.006

Highlights

•    Partnered women blindly rated their partner's body odor as smelling sexier than the body odor of unknown males.
•    Partnered women blindly rated their partner's body odor as smelling less strong than the body odor of unknown males.
•    Partnered women were unlikely to rank their partner's body odor as most preferred in a pool including six unknown males.
•    Partnered women could reliably recognise their partner's body odor.
•    Body odor preference ratings appear to be driven by familiarity ratings.

Abstract: Despite evidence indicating body odor (BO) preference is an important driver in mate selection, previous studies have only investigated females' preferences for the BO of strangers. Therefore, the aim of the current study was to determine if partnered females prefer their partner's BO compared to that of others males' BO. Forty partnered and 42 single, heterosexual women aged 18–35 years, brought to the laboratory a shirt their partner or male friend/relative (respectively) sweated in while wearing. The results indicated that both partnered and single women (blindly) rated their known donor's BO as smelling significantly more similar, familiar and sexy compared to six unknown male's BO, but rated their known donor's BO as less intense smelling than unknown males' BO. While participants indicated they liked their known donor's BO more than that of unknown males' BO, the difference was not statistically significant. Moreover, participants were unlikely to rank their known donor's BO as their most preferred of seven BOs. Finally, partnered and single participants could reliably recognise their known donor's BO and that of unknown males' which was driven by their ability to indicate a stranger's BO was not that of known donor's. Overall, these preliminary findings suggest that partnered females may prefer their partners' BO but this preference may not be due to mate selection but instead a consequence of repeated exposure to their partner's BO.



Self-harm in older adults: Loss of control, increased loneliness and perceived burdensome ageing were reported self-harm motivations

Self-harm in older adults: systematic review. M. Isabela Troya et al. The British Journal of Psychiatry, Volume 214, Issue 4, April 2019, pp. 186-200. https://doi.org/10.1192/bjp.2019.11

Abstract
Background: Self-harm is a major public health concern. Increasing ageing populations and high risk of suicide in later life highlight the importance of identification of the particular characteristics of self-harm in older adults.

Aim: To systematically review characteristics of self-harm in older adults.

Methods: A comprehensive search for primary studies on self-harm in older adults was conducted in e-databases (AgeLine, CINAHL, PsycINFO, MEDLINE, Web of Science) from their inception to February 2018. Using predefined criteria, articles were independently screened and assessed for methodological quality. Data were synthesised following a narrative approach. A patient advisory group advised on the design, conduct and interpretation of findings.

Results: A total of 40 articles (n = 62 755 older adults) were included. Yearly self-harm rates were 19 to 65 per 100 000 people. Self-poisoning was the most commonly reported method. Comorbid physical problems were common. Increased risk repetition was reported among older adults with self-harm history and previous and current psychiatric treatment. Loss of control, increased loneliness and perceived burdensome ageing were reported self-harm motivations.

Conclusions: Self-harm in older adults has distinct characteristics that should be explored to improve management and care. Although risk of further self-harm and suicide is high in all age cohorts, risk of suicide is higher in older adults. Given the frequent contact with health services, an opportunity exists for detection and prevention of self-harm and suicide in this population. These results are limited to research in hospital-based settings and community-based studies are needed to fully understand self-harm among older adults.

Overestimating the Valuations of Others: People Perceive Others as Experiencing Everything More Intensely

Jung, Minah and Moon, Alice and Nelson, Leif D., Overestimating the Valuations of Others: People Perceive Others as Experiencing Everything More Intensely (February 4, 2019). SSRN, http://dx.doi.org/10.2139/ssrn.3352888

Abstract: People often make judgments about their own and others’ valuations and preferences. Across 12 studies (N=17,939), we find a robust bias in these judgments such that people tend to believe that others have more intense experiences than they do, leading to overestimation of others’ valuations and preferences. We argue that this overestimation arises because estimations of others’ preferences rely on people’s intuitive, core representations of the experience itself (i.e., whether the experience is positive or negative). We first demonstrate that the overestimation bias is pervasive for a wide range of positive (Studies 1-4) and negative experiences (Study 5), and is not merely an artifact of how preferences are measured (Study 6). This overestimation bias ultimately forms a paradox in how people think that others tradeoff between valuation and utility (Study 7). Specifically, people believe that an identically-paying other would enjoy the same experience more than they would, but also that an identically-enjoying other would pay more for the same experience. Such paradoxical judgments do not extend to domains unrelated to preference and valuation (Studies 8A-8B), but do extend to other preference measures, such as willingness-to-wait (Studies 9-10). Finally, consistent with a core representation explanation, explicitly prompting people to consider the entire distribution of others’ preferences significantly reduced or eliminated the bias (Study 11). These findings suggest that social judgments of others’ preferences are not only largely biased, but they also ignore how others make trade-offs between evaluative metrics.

Keywords: overestimation bias, comparative judgments, valuation, preferences, paradox

Thursday, April 11, 2019

We document a positive relationship between the endorsement of good citizenship (voting, paying taxes, staying informed, etc.) and narcissism, and a negative relationship for psychopathy

Who makes a good citizen? The role of personality. Scott Pruysers, Julie Blais, Phillip G.Chen. Personality and Individual Differences. Volume 146, 1 August 2019, Pages 99-104. https://doi.org/10.1016/j.paid.2019.04.007

Abstract: In this paper we explore the link between personality and attitudes towards good citizenship and civic duty. To do so we recruited 371 eligible Canadian voters from a national panel, asking a variety of questions regarding their level of political participation and attitudinal questions regarding the importance of a number of behaviors typically associated with good citizenship (i.e., voting, paying taxes, staying informed, etc.). Importantly, we included two batteries of personality items: the HEXACO, which covers general personality (Honesty-Humility, Emotionality, Extraversion, Agreeableness, Conscientiousness, and Openness to Experience), and the Dark Triad (psychopathy, narcissism, and Machiavellianism). The analysis reveals a consistent and important explanatory role for personality, even after controlling for standard explanatory factors such as age, gender, income, education, political interest, knowledge, efficacy, and placement on the left-right scale. Among other findings, we document a positive relationship between the endorsement of good citizenship and narcissism, and a negative relationship for psychopathy.


Prejudiced and unaware of it: Evidence for the Dunning-Kruger model in the domains of racism and sexism

Prejudiced and unaware of it: Evidence for the Dunning-Kruger model in the domains of racism and sexism. Keon West, Asia A.Eaton. Personality and Individual Differences, Volume 146, 1 August 2019, Pages 111-119. https://doi.org/10.1016/j.paid.2019.03.047

Abstract: Prior research, and high-prolife contemporary examples, show that individuals tend to underestimate their own levels of bias. This underestimation is partially explained by motivational factors. However, (meta-) cognitive factors may also be involved. Conceptualising contemporary egalitarianism as type of skill or competence, this research proposed that egalitarianism should conform to the Dunning-Kruger model. That is, individuals should overestimate their own ability, and this overestimation should be strongest in the least competent individuals. Furthermore, training should improve metacognition and reduce this overestimation. Two studies on racism (N = 148), and sexism (N = 159) partially supported these hypotheses. In line with the Dunning-Kruger model, participants overestimated their levels of racial and gender-based egalitarianism, and this pattern was strongest among the most prejudiced participants. However, diversity training did not affect participants' overestimation of their egalitarianism. Implications for contemporary prejudice, and prejudice-reducing strategies are discussed.


Joint attention skills in wild Arabian babblers (Turdoides squamiceps): a consequence of cooperative breeding?

Yitzchak Ben Mocha et al. Joint attention skills in wild Arabian babblers (Turdoides squamiceps): a consequence of cooperative breeding?, Proceedings of the Royal Society B: Biological Sciences (2019). Apr 3 2019. DOI: 10.1098/rspb.2019.0147

Abstract

Human cooperation strongly relies on the ability of interlocutors to coordinate each other's attentional state: joint attention. One predominant hypothesis postulates that this hallmark of the unique cognitive system of humans evolved due to the combination of an ape-like cognitive system and the prosocial motives that facilitate cooperative breeding. Here, we tested this hypothesis by investigating communicative interactions of a cooperatively breeding bird species, the Arabian babbler (Turdoides squamiceps). The behaviour of 12 wild social groups was observed focusing on two distinct communicative behaviours: object presentation and babbler walk. The results showed that both behaviours fulfilled the criteria for first-order intentional communication and involved co-orientation of recipients' attention. In turn, recipients responded with cooperative and communicative acts that resulted in coordinated joint travel between interlocutors. These findings provide the first evidence that another animal species shows several key criteria traditionally used to infer joint attention in prelinguistic human infants. Furthermore, they emphasize the influence of cooperative breeding on sophisticated socio-cognitive performances, while questioning the necessity of an ape-like cognitive system underlying joint attentional behaviour.

1. Introduction

The extraordinary degree of cooperation exhibited by humans seems unrivalled in the animal kingdom [1,2]. Theorists have implicated a specific cognitive capacity, joint attention, as one of the essential building blocks for the evolution of the cooperative abilities of humans [1,3]. Traditionally, joint attention has been defined as the ability to attract and coordinate the attention of a recipient towards a locus of mutual interest (e.g. an object/event in the environment [4]). Precursors of this cognitive capacity can already be found in human infants at the age of approximately six months, who respond to joint attention by following the direction of a caretaker's gesture [5]. At the age of 9–12 months, infants are capable of initiating joint attention with a social partner by gesturing towards a locus of mutual interest [4]. Consequently, the development of joint attention skills is seen as a fundamental milestone in the ontogeny of human cooperative communication [5,6]. Some scholars even see joint attention as the ‘small difference that made a big difference’ in the cognitive evolution of our species [3].

One predominant hypothesis about the evolution of human sophisticated social cognition, the ‘cooperative breeding’ hypothesis [2], postulates that cooperative breeding installed prosocial psychological functioning supporting systematic alloparental care. This, in turn, resulted in immediate consequences for socio-cognitive performance [7]: Caretakers of cooperative breeders evolved specific cognitive capacities for understanding the needs of others' offspring. In parallel, the offspring developed elaborate communicative signalling to attract attention and care from caretakers other than their mothers [8]. Concerning humans, it has been argued that the exceptional co-occurrence of an existing ape-like cognitive system together with humans’ systematic reliance on alloparental care [9,10] gave rise to unique socio-cognitive capacities such as joint attention (figure 1) [2,7].

...

However, are joint attentional skills indeed uniquely human and is the combination of an ape-like cognitive system and cooperative breeding a crucial prerequisite?

To date, relatively little is known about joint attentional skills and the acting selection pressures in other animal species. Furthermore, whether specific behaviours of non-human animals towards human caretakers (e.g. gaze alternation in chimpanzees, Pan troglodytes [11]; pointing in bottlenose dolphins, Tursiops truncatus [12]; and vocal learning in grey parrots, Psittacus erithacus [13]) qualify as joint attentional skills in the human sense is subject to a contentious debate [3,14,15].

Here, we revisited the claim that joint attentional skills are a uniquely human ability [3,15] and tested whether the combination of an ape-like cognitive system and cooperative breeding represents a necessary requirement for joint attention to unfold [2]. We predicted that if an ape-like cognitive system and cooperative breeding are both necessary for joint attention [2,7], bird species will not exhibit key hallmarks of this trait. However, if an ape-like cognitive system is not necessary, but cooperative breeding does facilitate the performance of joint attention skills [16], cooperatively breeding species will demonstrate hallmarks of joint attention. To test these predictions, we investigated communicative interactions in a cooperatively breeding bird species, the Arabian babbler (Turdoides squamiceps), in the wild.

Arabian babblers live in stable social groups [17], consisting of 2–20 kin and non-kin from both sexes [17]. All members provide substantial allopaternal care and use elaborate communicative signalling [17]. We focused on two distinct signals, ‘object presentation’ [18] and ‘babbler walk’, which are frequently used to solicit following behaviour from conspecifics. object presentation involves the discreet presentation of an object to attract the recipient's attention without being seen by other group members. The goal is to lead the recipient towards a hidden location for copulation [18] (see electronic supplementary material, video S1). babbler walk is a multi-modal signal that involves conspicuous wing waving and vocalizations, and is used to solicit a conspecific to follow the signaller (figure 2).

...

We paid special attention to two distinct issues that have hampered comparative research on joint attention. First, disagreement on an applicable definition of joint attention has so far prevented valid quantitative comparisons between human and other animal species [19–21]. For example, some define joint attention as the ‘intentional co-orientation of two or more organisms to the same locus’ [21]. Others (e.g. [3]), by contrast, require complex mind reading and define it as ‘the mutual awareness of having attended to the same entity between two (or more) individuals. Mutual awareness is established through communication by at least one individual during mutual gaze’ [20]. To overcome this lack of consensus, we refrained from testing whether communicative episodes between Arabian babblers fit a specific definition. Instead, we investigated whether communicative interactions that were initiated by object presentation and babbler walk fulfilled distinct hallmarks that have traditionally been used to infer joint attention in prelinguistic human infants: (i) intentional communication (e.g. [21,22]), (ii) co-orientation of attention (e.g. [4,15]) and (iii) mutual awareness (e.g. [20,23]). By applying this approach, we aimed to instigate a constructive discussion on joint attentional skills that provides useful tools to pinpoint the different degrees of joint attention and cognitive capacities involved [19].

Second, research on joint attention in non-human species has been strongly biased towards interactions with objects (e.g. [12,20]). However, joint attention can revolve around any type of locus [15] such as, for instance, the interlocutors themselves, or the activity they are performing at the time [4,24]. Hence, we examined whether signallers acted to attract and co-orient recipients' attention to their joint travel.

We thus investigated whether communicative episodes initiated by object presentation and babbler walk fulfil the following three key hallmarks of joint attention (see table 1 and methods for detailed operational criteria).


Check also Yitzchak Ben Mocha et al. Intentional Presentation of Objects in Cooperatively Breeding Arabian Babblers (Turdoides squamiceps), Frontiers in Ecology and Evolution (2019). DOI: 10.3389/fevo.2019.00087

Popular: Attention skills in a nonhuman cooperative breeding species. Max Planck Society Press Article, Apr 11 2019. https://phys.org/news/2019-04-attention-skills-nonhuman-cooperative-species.html

Speaking like a Man: Women’s Pitch as a Cue for Gender Stereotyping --Women’s average voice pitch has decreased in recent years, reducing the gap between men on this vocal dimension

Speaking like a Man: Women’s Pitch as a Cue for Gender Stereotyping. Barbara Krahé, Lida Papakonstantinou. Sex Roles, April 11 2019. https://link.springer.com/article/10.1007/s11199-019-01041-z

Abstract: Women’s average voice pitch has decreased in recent years, reducing the gap between men on this vocal dimension. The present study examined whether a woman speaking at a lower pitch would be perceived as less feminine and more masculine than a woman speaking at a higher pitch. Participants (n = 100, 67 female) listened to an audiotape of a woman in which her natural voice was manipulated to represent a pitch of either 220 Hz or 165 Hz. They then rated her on positive and negative facets of masculinity and femininity as well as competence and likeability. In addition, participants’ gendered self-concept was measured to examine potential moderator effects. As predicted, positive masculinity ratings were significantly higher, and positive and negative femininity ratings were significantly lower, in the 165 Hz than in the 220 Hz condition. The woman was also rated as more likeable in the 220 Hz than in the 165 Hz condition. No difference was found for negative masculinity and competence ratings, and no moderation effect of participants’ gendered self-concept emerged. The findings suggest that lower voice pitch is a masculinity cue that elicits stereotyped perceptions of female speakers and may have implications for impression formation in a variety of domains.

Keywords: Gender stereotypes Voice pitch Masculinity Femininity Likeability

Hungry People Prefer Larger Bodies and Objects: The Importance of Testing Boundary Effects

Saxton, Tamsin, Kristofor McCarty, Jasmine Caizley, Dane McCarrick, and Thomas V. Pollet. 2019. “Hungry People Prefer Larger Bodies and Objects: The Importance of Testing Boundary Effects.” PsyArXiv. April 11. doi:10.31234/osf.io/s7ta8

Abstract: Several experimental studies have indicated that when people are hungry, they assess larger women’s bodies as more attractive, compared to when they are satiated. These satiety-dependent judgements are assumed to contribute to the noted cross-cultural differences in attitudes towards women’s adiposity. However, it is premature to make this assumption until satiety-dependent judgements of stimuli other than female bodies have also been tested. Accordingly, we collected attractiveness judgements of female and male bodies manipulated to vary in size by varying level of adiposity, and objects manipulated to vary in size, from 186 participants who also reported their current hunger level. We found that larger sizes of stimuli in general, and women’s bodies in particular, especially when judged by women, were judged as more attractive at higher levels under conditions of hunger. We discuss these patterns in the context of the Insurance Hypothesis, the Environmental Security Hypothesis, and the impact of hunger on acquisition.

From 2013... Do not end the filibuster: Because narrow Senate majorities often represent only a minority of Americans, many filibusters are not at odds with majority rule at all

The Majoritarian Filibuster. Benjamin Eidelson. Yale Law Journal (2013), Volume 122, Issue 4. https://digitalcommons.law.yale.edu/cgi/viewcontent.cgi?article=5549&context=ylj

ABSTRACT:The debate over the Senate filibuster revolves around its apparent conflict with the principle of majority rule. Because narrow Senate majorities often represent only a minority of Americans, however, many filibusters are not at odds with majority rule at all. Bypaying attention to such "majoritarian filibusters," this Note aims to disrupt the terms of the traditional debate and open up a new space for potential compromise. This Note reports the first empirical study of the majoritarian or countermajoritarian character of recent filibusters. These data reveal that, in half of the Congresses over the past two decades, successful filibustering minorities usually represented more people than the majorities they defeated. The choicewhether to preserve the filibuster therefore cannot be reduced to a simple choice between majority rule and minority rights. After exploring the distribution of majoritarian and countermajoritarian filibusters along other dimensions of interest, this Note proposes that themajority-rule principle might be better served by simply reducing the sixty-vote cloture threshold-thereby shifting the balance toward majoritarian as opposed to countermajoritarian filibusters-than by abolishing the filibuster altogether.

Even in the rare cases where smartphones might alter cognition, this effect is likely transitory

An examination of the potential lingering effects of smartphone use on cognition. Peter Frost et al. Applied Cognitive Psychology, March 18 2019. https://doi.org/10.1002/acp.3546

Summary

Smartphones might offer an extension of our own cognitive abilities, potentially preventing practice of certain forms of cognition. Our first study established that heavier usage of smartphones was negatively correlated with social problem solving and delayed gratification, as well as positively correlated with some aspects of critical thinking. Studies 2 and 3 involved experiments where participants were assigned to either a lower or higher smartphone usage group. In both experiments, higher usage of smartphones led only to a diminished ability to interpret and analyze the deeper meaning of information. However, Study 3 showed that, after a 4‐week interval, the difference in the ability to interpret and analyze meaning between lower and higher phone usage groups was no longer evident. The findings of this study suggest that, even in the rare cases where smartphones might alter cognition, this effect is likely transitory.

1 INTRODUCTION

In his book, “The Shallows,” Carr (2010) suggests the following when it comes to how technology might be changing our cognition:

    Over the past few years I've had the uncomfortable sense that someone, or something, has been tinkering with my brain, remapping the neural circuitry, reprogramming the memory. My mind isn't going—so far as I can tell—but it's changing. I'm not thinking the way I used to think. (Carr, 2010, p. 5)

Other popular media and books portray smartphones, social media, and other technology as diminishing cognitive capacities, like attention and concentration (Bauerlein, 2011).

Smartphone technology, in particular, is taking on an increasingly larger role in our daily mental activities. Pew Research data show that 77% of all U.S. adults had a smartphone in 2018, up from 35% in 2011 (Pew Research Center, 2018). The Pew Center also indicated that, in 2018, 94% of people from age 18 to 29 owned a smartphone. While access to smartphone technology has grown, so too has the body of literature investigating the concurrent and immediate residual inhibitory effects of these devices on certain forms of cognition, particularly attention (Strayer, Cooper, Turrill, Coleman, & Hopman, 2015; Strayer & Drews, 2007). Our study, however, focuses more on the potential for longer term effects these devices might exert on higher order cognition, including the ability to think critically, problem solve, reason, and engage in executive control. Some researchers acknowledge that consideration of the intersection between cognition and technology is an understudied area in psychology (Pennycook, Fugelsang, & Koehler, 2015; Wilmer, Sherman, & Chein, 2017).

If we consider the neuroplasticity of the brain—its ability to physically alter neural connectivity on the basis of changes in the environment and experience—could smartphone technology, which provides immediate and 24/7 access to the internet, be altering our cognitive abilities? Underlying this debate is the neuropsychological phenomenon of “use‐it‐or‐lose it,” demonstrated by neuroimaging and physiological studies that show new experiences strengthen synaptic connections in areas of the brain frequently used while weakening connections that are rarely used (Carr, 2010). Reliance on mobile phone technology as a form of “extended cognition” (Barr, Pennycook, Stolz, & Fugelsang, 2015; Clayton, Leshner, & Almond, 2015) or “ibrain” (Small & Vorgan, 2008) might be leading to changes occurring in the brain that alter our ability to engage in various cognitive processes. Might easy access to information take away from practice of more deliberative thoughts and critical thinking skills? Moreover, might the constant notifications and cues provided by mobile phones be interrupting our ability to engage in higher cognition and/or delay gratification for longer term goals?

Some studies, such as that by Barr et al. (2015), have examined whether there may be a correlation between analytical thinking and smartphone technology. Barr and colleagues found that people who relied more heavily on smartphones and information sources performed worse on analytic‐thinking tasks. In a separate review article, Pennycook et al. (2015) acknowledged that this preliminary research suggests that smartphones may serve as a “second brain” that allows people to offload thinking.

Some studies show that smartphones might influence other forms of higher order cognitive functions, such as executive function and ability to delay gratification. The ability to resist temptation in favor of long‐term goals has important implications for individual, societal, and economic success (Casey et al., 2011). Delay of gratification is also negatively correlated with the control abilities in children and adults (Casey et al., 2011; Metcalfe & Mischel, 1999).

Wilmer and Chein (2016) showed that higher scores on a self‐report measure of mobile technology engagement was correlated with a weaker tendency to delay gratification, as measured by a delay discounting task. Their self‐report questionnaire measured (a) daily usage of social media apps, (b) frequency of posting public status updates, and (c) phone‐checking behavior. Wilmer and Chein found a negative correlation between mobile device engagement and delay of gratification. They also found that this relationship might be specifically mediated by individual differences in impulse control and not reward sensitivity. The correlational nature of this study limited inferences about causation, but did show an interesting association between mobile device usage and habits associated with delay of gratification.

There is also evidence that the use of smartphones is correlated with some subjective reports associated with attention. Marty‐Dugas, Ralph, Oakman, and Smilek (2018) found that the results of a self‐report that assessed attention lapses, attention‐related errors, and mind wandering was positively related to results of a self‐report that assessed extent of smartphone use. These researchers found the correlation was particularly strong for participants who used smartphones without a specific purpose in mind (for what they referred to as “absent‐minded” usage). Even the mere presence of smartphones can interrupt attention and task performance (Thornton, Faires, Robbins, & Rollins, 2014). These studies show a relationship between concurrent smartphone use and attention. What about lingering effects on attention?

There is research showing that the multitasking aspect of smartphone technology habits, particularly for purposes of using social media, might relate to longer term effects on control of attention and concentration. Ophir, Clifford, and Wagner (2009) had participants engage in a number classification task (even or odd?) or letter classification task (vowel or consonant?). They then occasionally switched tasks. They calculated a “switch cost” as the difference in mean response time between trials preceded by a trial of the other type (switch trials) minus trials preceded by a trail of the same type (nonswitch trials). The switch cost for heavy social media multitaskers was 167 ms greater than that of low social media multitaskers. Heavy social media multimedia users performed worse on a test of task switching, perhaps—they speculated—because of reduced ability to filter out interference from irrelevant representations.

Relevant to smartphone usage for social networking purposes, studies show a positive association between heavier usage of social networking sites and diminished cognitive control or lack of judgment (Alloway & Alloway, 2012; Cao, Masood, Luqman, & Ali, 2018; Chen & Kim, 2013). Chen and Kim (2013) found that, if heavier users of social networking sites went to them for entertainment or pleasure, those desires overrode privacy concerns, such as unauthorized secondary use and improper access. Heavier usage was also associated with greater problematic social networking behaviors. Chen and Kim identified problematic social networking use based on Young's (1998) 20‐item version of problematic Internet use, and items were adjusted to be more relevant to the context of social networking. For example, respondents were asked if they found themselves staying on social networking sites longer than they intended, and if they feared that life without social networking sites would be empty and joyless. They suggest that problematic use might be a compulsivity control issue that cannot be overridden by recognition of potential long‐term exposure to harm. Again, though, a causal link was not established in this particular study. It is unclear whether heavy usage of social networking attracts people with less cognitive control or if social networking may be contributing to a lack of cognitive control. Some of these studies also emphasize the most extreme cases of heavy technology usage.

Some studies also find a negative association between the use of mobile phone technology and working memory (Abramson et al., 2009). Abramson et al. (2009) administered a questionnaire about mobile phone usage. They administered cognitive tests and found that the more frequently calls were made per week, the poorer was working memory accuracy and reaction time for a simple learning task was shorter.

Some studies have also explored whether the frequent interruptions from smartphones influences social reasoning and learning. Reed, Hirsh‐Pasek, and Golinkoff (2017) conducted an experiment where they found that phone interruptions that occurred when a mother was attempting to teach their 2‐year‐old novel words lead to poorer language acquisition. Though these studies show a concurrent effect of smartphone interruptions on social reasoning and learning, few studies have explored lingering effects of smartphone use on social cognition. Other studies show evidence that reliance on smartphone use for social interactions might correlate with poorer social skills and reasoning (e.g., Jin & Park, 2012). Our series of studies, particularly Studies 2 and 3, included controlled experiments to explore causative aspects pertaining to lingering effects of smartphone use.

It should be noted that whereas some studies have explored potential associations between smartphone usage and cognition, some studies have also explored whether exposure to the electromagnetic radiation emitted by smartphone technology alters cognition and brain physiology. Recent research shows that exposure to electromagnetic fields from smartphones does not alter event‐related potentials, like N100, P200, N200, P300 latencies and N2‐P300 amplitudes (Mohan, Khaliq, Panwar, & Vaney, 2016), nor do these fields alter measures of attention and short‐term memory (Cinel, Boldini, Fox, & Russo, 2008). Therefore, it is not likely that electromagnetic fields will confound an examination of how smartphone activities (for social media, phone calls, internet browsing, etc.) might influence cognition.

Our first study explored whether smartphone usage correlated with various measures of higher order cognition, including the Delayed Gratification Inventory, Cornell Critical Thinking Test, Level Z (for college‐age participants), and Modified Means End Problem Solving. The Modified Means End was used to assess social problem solving because we suspected that higher rates of mobile phone technology and social media might lead to a lack of practice with social problem solving. Although a study by Ekinci (2014) found that problematic internet use was positively correlated with the perception of avoidant and impulsive problem solving styles, no one to our knowledge has examined the relationship between use of smartphones and direct (rather than perceptions of) problem solving.

Once we identified relationships between mobile device usage and various forms of cognition, we then used an experimental manipulation in Study 2 to determine if there were any causal links. Only the cognitive tests and scales found to be related to cognition in Study 1 were investigated in Study 2. Study 3 was intended to replicate the findings in Study 2, as well as include a longer interval of time associated with manipulation of smartphone usage.

Given previous research (e.g., Wilmer & Chein, 2016) and our suspicion that more frequent smartphone usage would lead to less reliance on higher cognition, we hypothesized that in Study 1, the use of smartphones should be negatively correlated with particular executive control abilities, particularly delay gratification and critical thinking. Further, we hypothesized in Studies 2 and 3 that higher rates of smartphone usage might cause diminished abilities associated with certain forms of higher cognition.

Our study adds to the literature on mobile phone technology and cognition by (a) examining some cognitive variables not previously associated with research on mobile technology usage, such as social problem solving and more aspects of critical thinking, (b) using tracking apps rather than self‐reports to more accurately and objectively measure usage rates, and (c) introducing experimental control in Studies 2 and 3.

We chose to use tracking apps rather than rely exclusively on self‐reports since studies have shown that people generally misjudge time durations, especially rapid, yet pervasive, checking behaviors (Grondin, 2010; Rachman, 2002). Andrews, Ellis, Shaw, and Piwek (2015) were the first to use a tracking software they developed to find out how much time was actually spent using mobile phones. Comparing self‐reported usage of mobile phones versus tracking app reports over 2 weeks, they found that their participants did not always self‐report some aspects of their mobile phone usage accurately. For example, they found that young adults far underestimated the average daily number of phone uses.

The evolutionary context of personality development: Ontogenetic and Deferred Adaptations

The evolutionary context of personality development. Marco del Giudice. In Handbook of Personality Development, Chapter 2. New York: Guilford, 2019. January 2019. https://www.researchgate.net/publication/316120672_The_evolutionary_context_of_personality_development

Ontogenetic and Deferred Adaptations
Looking at developmental stages through the lens of biological function suggests a useful distinction between two kinds of adaptations that are often observed in early life. Ontogenetic adaptations are designed to serve their fitnessenhancing function at a specific time in development, and often disappear as soon as they are no longer needed. Examples include the placenta (a fetal organ that provides nourishment and other vital functions during the fetal stage and is discarded immediately after birth) and infantile reflexes, such as the suckling reflex. Deferred adaptations are traits that appear in childhood but function—at least in part—to prepare children for adult behavior (Bjorklund & Ellis, 2014). Play is a paramount example of a deferred adaptation; in humans and other mammals, playing trains youngsters to deal with unexpected events and, at the same time, paves the way to the acquisition of specialized adult skills (e.g., foraging, fighting, parenting) (Geary, 2010; Spinka, Newberry, & Bekoff, 2001). The concept of an ontogenetic adaptation is particularly useful to understand the limits of early experiences in shaping adult personality. Some behavioral traits expressed in childhood serve important functions in the context of family life but may cease to be useful as the child turns into an independent adult. These traits may either disappear or get repurposed in a different form in the service of new developmental goals. For example, attachment styles in infancy are largely determined by the parents’ caregiving styles and show negligible genetic effects. In middle childhood, attachment styles start to become differentiated by sex, possibly under the influence of adrenal androgens; adults’ attachment styles to romantic partners are only weakly correlated with those of infancy, and reflect a sizable contribution of genetic factors (Barbaro, Boutwell, Barnes, & Shackelford, 2017; Del Giudice, 2009, 2015a). At an even deeper level, the existence of parent–offspring conflict implies that the parents’ behavior is not completely in the best interest of their children.

For this reason, children should not passively accept the influence of parents; instead, they should show a certain amount of developmental “resistance” to parental shaping. While it is difficult to directly test this hypothesis, parent– offspring conflict may well contribute to explain why family experiences have only small and inconsistent effects on the development of adult personality.

Rolf Degen summarizing: The emergence of the ability to build elevated sleeping nests allowed great apes to adopt a more comfortable & human-like sleep posture than the one monkeys take up

Nesting, sleeping, and nighttime behaviors in wild and captive great apes. James R. Anderson, Mabel Y. L. Ang, Louise C. Lock, Iris Weiche. Primates, Apr 10 2019. https://link.springer.com/article/10.1007/s10329-019-00723-2

Abstract: The past few decades have seen a burgeoning of scientific studies on great apes’ use of nests for sleeping in the wild, as well as their nesting behavior and sleep in captivity. We review recent advances in knowledge of these topics, with the aim of promoting information exchange between people working in the field and with captive great apes. We trace developments in research into nest-building techniques in adults and immatures, factors that influence selection of general sleeping sites and specific locations, social aspects of sleep, postures, and nighttime activities. We argue that exchanges of information deriving from studies of captive and wild apes are valuable for obtaining a better understanding of sleep-related adaptations in our nearest evolutionary neighbors, and conclude by making some recommendations regarding sleeping arrangements in captivity from a welfare perspective.

Keywords: Chimpanzee Bonobo Gorilla Orangutan Nest building Sleep posture Sleep quality Environmental enrichment Welfare


Wednesday, April 10, 2019

Why is age so important in human mating? Evolved age preferences and their influences on multiple mating behaviors

Conroy-Beam, D., & Buss, D. M. (2019). Why is age so important in human mating? Evolved age preferences and their influences on multiple mating behaviors. Evolutionary Behavioral Sciences, 13(2), 127-157. http://dx.doi.org/10.1037/ebs0000127

Abstract: Evolutionary theorizing suggests that chronological age, because it is so strongly linked with key reproductive qualities like fertility, should be an exceptionally consequential variable in mate selection. We review voluminous evidence for mate preferences for age and the substantial and varied behavioral sequelae of those preferences. These include (a) in actual marriage decisions, men choose younger wives, and women choose older husbands, on average in all of the dozens of cultures studied; (b) in personal advertisements, men and women seek partners consistent with their expressed age preferences; (c) chronological age determines number of “hits” received in online dating services; (d) the age of potential bride influences the amount of money spent on premarriage customs; (e) men’s mate retention effort, including commitment manipulation, resource provisioning, and intrasexual threats, is significantly predicted by the wife’s age; and (f) chronological age is an important sex-linked cause of divorce. The far-reaching ramifications of age also extend to (g) tactics of intrasexual competition, (h) predictors of mate value discrepancies, (i) victims of sex crimes, and (j) prostitution patterns. Finally, chronological age predicts (k) probability of remarriage, and (l) the age gap between grooms and brides upon remarriage. We synthesize evidence from diverse methods, across different cultures, and over time spans of centuries. Massive converging evidence provides a powerful, yet complex, understanding of the evolutionary importance of age in multiple mating outcomes over the human life span.

Popular version: What We Know About Age Gaps in Dating, Love, and Marriage. Theresa E DiDonato. Psychology Today, Apr 10, 2019. https://www.psychologytoday.com/ca/blog/meet-catch-and-keep/201904/what-we-know-about-age-gaps-in-dating-love-and-marriage

Those with posttraumatic stress disorder frequently experience unwanted memories of their traumas, even when making explicit efforts to avoid them, while healthy individuals can suppress those memories

Behavioral and neural correlates of memory suppression in PTSD. Danielle R. Sullivan et al. Journal of Psychiatric Research, Volume 112, May 2019, Pages 30-37. https://doi.org/10.1016/j.jpsychires.2019.02.015

Highlights
•    Trauma exposure is associated with behavioral difficulties in memory suppression.
•    Right middle frontal gyrus activity is reduced during memory suppression after trauma exposure.
•    Trait suppression is negatively correlated with reduced right middle frontal gyrus activity.

Abstract: Previous work has shown that healthy individuals can actively suppress emotional memories through recruitment of the lateral prefrontal cortex. By contrast, individuals with posttraumatic stress disorder (PTSD) frequently experience unwanted memories of their traumatic experiences, even when making explicit efforts to avoid them. However, little is known regarding the behavioral and neural effects of memory suppression among individuals with PTSD. We examined memory suppression associated with PTSD using the Think-No-Think paradigm in an event-related functional magnetic resonance imaging (fMRI) study. We studied three groups: PTSD (n = 16), trauma exposure without PTSD (n = 19), and controls (i.e., no trauma exposure or PTSD; n = 13). There was a main effect of memory suppression such that participants remembered fewer face-picture pairs during the suppress condition than the remember condition. However, trauma-exposed participants (regardless of PTSD status) were less likely to successfully suppress memory than non-trauma-exposed controls. Neuroimaging data revealed that trauma-exposed individuals showed reduced activation in the right middle frontal gyrus during memory suppression. These results suggest that trauma exposure is associated with neural and behavioral disruptions in memory suppression and point to the possibility that difficulty in active suppression of memories may be just one of several likely factors contributing to the development of PTSD.


We see evidence of an evolutionary design supportive of attachment as well as reproductive exigencies of procreative well-being; there is an ethological case to be made for considering pornography use as a public health risk

Procreative well-being and pornography – analyzing the script. Public health implications revealed through an ethological lens. Mark H. Butler.Marriage & Family Review, Apr 9 2019. https://doi.org/10.1080/01494929.2019.1588187

Abstract: An ethological model of human procreative well-being is proposed and the goodness-of-fit of pornography’s script to that model is considered. Deducing an evolutionary template for procreative well-being from an ethological analysis links attachment dynamics to procreative success. Alongside parent–child attachment, pair-bond attachment in the procreative couple looms large as an element of optimal procreative relationship structure and quality. Key elements of pair-bond attachment are documented. Turning next to an empirical examination of the sexual behavioral system in humans, we see evidence of an evolutionary design supportive of attachment as well as reproductive exigencies of procreative well-being. Sexual system mechanisms promoting both reproduction and attachment are evident in the evolutionary design. We next employ script theory to identify key elements of the sexual script promulgated by pornography. Joining these two analyses, we compare the evolutionary, attachment-based template for procreative success in juxtaposition to pornography’s sexual script to evaluate the goodness-of-fit of pornography use to attachment success and, by extension, procreative well-being. We conclude that there is an ethological case to be made for considering pornography use as a public health risk. Implications of the model of procreative well-being for the practice of couple therapy are given mention.

Keywords: attachment, ethology, family, marriage, pornography, procreative well-being, sexual behavioral system, sociobiology

Long-term benefit of Microbiota Transfer Therapy on autism symptoms and gut/fecal microbiota

Long-term benefit of Microbiota Transfer Therapy on autism symptoms and gut microbiota. Dae-Wook Kang, James B. Adams, Devon M. Coleman, Elena L. Pollard, Juan Maldonado, Sharon McDonough-Means, J. Gregory Caporaso & Rosa Krajmalnik-Brown. Scientific Reports, volume 9, Article number: 5821 (2019). Apr 9. https://www.nature.com/articles/s41598-019-42183-0

Abstract: Many studies have reported abnormal gut microbiota in individuals with Autism Spectrum Disorders (ASD), suggesting a link between gut microbiome and autism-like behaviors. Modifying the gut microbiome is a potential route to improve gastrointestinal (GI) and behavioral symptoms in children with ASD, and fecal microbiota transplant could transform the dysbiotic gut microbiome toward a healthy one by delivering a large number of commensal microbes from a healthy donor. We previously performed an open-label trial of Microbiota Transfer Therapy (MTT) that combined antibiotics, a bowel cleanse, a stomach-acid suppressant, and fecal microbiota transplant, and observed significant improvements in GI symptoms, autism-related symptoms, and gut microbiota. Here, we report on a follow-up with the same 18 participants two years after treatment was completed. Notably, most improvements in GI symptoms were maintained, and autism-related symptoms improved even more after the end of treatment. Important changes in gut microbiota at the end of treatment remained at follow-up, including significant increases in bacterial diversity and relative abundances of Bifidobacteria and Prevotella. Our observations demonstrate the long-term safety and efficacy of MTT as a potential therapy to treat children with ASD who have GI problems, and warrant a double-blind, placebo-controlled trial in the future.

From 2018: Concern for Group Reputation Increases Prosociality in Young Children

From 2018: Concern for Group Reputation Increases Prosociality in Young Children. Jan M. Engelmann, Esther Herrmann, Michael Tomasello. Psychol Sci. 2018 Feb;29(2):181-190. doi: 10.1177/0956797617733830

Abstract: The motivation to build and maintain a positive personal reputation promotes prosocial behavior. But individuals also identify with their groups, and so it is possible that the desire to maintain or enhance group reputation may have similar effects. Here, we show that 5-year-old children actively invest in the reputation of their group by acting more generously when their group’s reputation is at stake. Children shared significantly more resources with fictitious other children not only when their individual donations were public rather than private but also when their group’s donations (effacing individual donations) were public rather than private. These results provide the first experimental evidence that concern for group reputation can lead to higher levels of prosociality.

Keywords: cooperation, reputation, group reputation, open data

Check also Botto, Sara Valencia, & Rochat, Philippe. (2018). Sensitivity to the evaluation of others emerges by 24 months. Developmental Psychology, 54(9), 1723-1734. https://www.bipartisanalliance.com/2018/08/children-reproduced-outcomes-that-were.html

Angry people are more likely to engage in debates with those of similar & opposing views, & seek out information confirming their views more frequently; anxious individuals tend to seek out information contradicting their opinions

Anger, Fear, and Echo Chambers: The Emotional Basis for Online Behavior. Dag Wollebæk et al. Social Media + Society, April 9, 2019. https://doi.org/10.1177/2056305119829859

Abstract: Emotions, such as anger and fear, have been shown to influence people’s political behavior. However, few studies link emotions specifically to how people debate political issues and seek political information online. In this article, we examine how anger and fear are related to politics-oriented digital behavior, attempting to bridge the gap between the thus far disconnected literature on political psychology and the digital media. Based on survey data, we show that anger and fear are connected to distinct behaviors online. Angry people are more likely to engage in debates with people having both similar and opposing views. They also seek out information confirming their views more frequently. Anxious individuals, by contrast, tend to seek out information contradicting their opinions. These findings reiterate predictions made in the extant literature concerning the role of emotions in politics. Thus, we argue that anger reinforces echo chamber dynamics and trench warfare dynamics in the digital public sphere, while fear counteracts these dynamics.

Keywords: emotions, echo chambers, trench warfare dynamics, anger, anxiety, online political behavior

Genetic selection/concentration is not an explanation for neighbourhood gradients in obesity & mental health problems; a modest genetic selection/concentration was evident for teen pregnancy and poor educational outcomes

Genetics and the geography of health, behaviour and attainment. Daniel W. Belsky, Avshalom Caspi, Louise Arseneault, David L. Corcoran, Benjamin W. Domingue, Kathleen Mullan Harris, Renate M. Houts, Jonathan S. Mill, Terrie E. Moffitt, Joseph Prinz, Karen Sugden, Jasmin Wertz, Benjamin Williams & Candice L. Odgers. Nature Human Behaviour (2019), April 8 2019, https://www.nature.com/articles/s41562-019-0562-1

Abstract: Young people’s life chances can be predicted by characteristics of their neighbourhood1. Children growing up in disadvantaged neighbourhoods exhibit worse physical and mental health and suffer poorer educational and economic outcomes than children growing up in advantaged neighbourhoods. Increasing recognition that aspects of social inequalities tend, in fact, to be geographical inequalities2,3,4,5 is stimulating research and focusing policy interest on the role of place in shaping health, behaviour and social outcomes. Where neighbourhood effects are causal, neighbourhood-level interventions can be effective. Where neighbourhood effects reflect selection of families with different characteristics into different neighbourhoods, interventions should instead target families or individuals directly. To test how selection may affect different neighbourhood-linked problems, we linked neighbourhood data with genetic, health and social outcome data for >7,000 European-descent UK and US young people in the E-Risk and Add Health studies. We tested selection/concentration of genetic risks for obesity, schizophrenia, teen pregnancy and poor educational outcomes in high-risk neighbourhoods, including genetic analysis of neighbourhood mobility. Findings argue against genetic selection/concentration as an explanation for neighbourhood gradients in obesity and mental health problems. By contrast, modest genetic selection/concentration was evident for teen pregnancy and poor educational outcomes, suggesting that neighbourhood effects for these outcomes should be interpreted with care.

Tuesday, April 9, 2019

We construct more precise and robust measures of GDP per capita using nighttime lights; we find that GDP per capita measures are less precise for middle and low income countries

Illuminating Economic Growth. Yingyao Hu, Jiaxiong Yao. IMF Working Paper No. 19/77. https://www.imf.org/en/Publications/WP/Issues/2019/04/09/Illuminating-Economic-Growth-46670

Summary: This paper seeks to illuminate the uncertainty in official GDP per capita measures using auxiliary data. Using satellite-recorded nighttime lights as an additional measurement of true GDP per capita, we provide a statistical framework, in which the error in official GDP per capita may depend on the country’s statistical capacity and the relationship between nighttime lights and true GDP per capita can be nonlinear and vary with geographic location. This paper uses recently developed results for measurement error models to identify and estimate the nonlinear relationship between nighttime lights and true GDP per capita and the nonparametric distribution of errors in official GDP per capita data. We then construct more precise and robust measures of GDP per capita using nighttime lights, official national accounts data, statistical capacity, and geographic locations. We find that GDP per capita measures are less precise for middle and low income countries and nighttime lights can play a bigger role in improving such measures.

Space ‘colonization’ will take place and will likely be fully automated; space mining will be the primary goal of space colonies; automation may lead to a technological singularity

Why space colonization will be fully automated. Riccardo Campa, Konrad Szocik, Martin Braddock. Technological Forecasting and Social Change, April 8 2019. https://doi.org/10.1016/j.techfore.2019.03.021

Highlights
•    Humans cannot survive for long periods of time in outer space.
•    Space ‘colonization’ will take place and will likely be fully automated.
•    Space mining will be the primary goal of space colonies.
•    Automation may lead to a technological singularity.
•    Space automation could limit the negative effects of an hostile Superintelligence.

Abstract: In this article we explore a possible scenario of space colonization and its consequences for planet Earth. We argue that in the short term space colonization will take place, but not in the form often presented in scientific and science fiction literature. Space colonies will be fully automated. There are three main reasons to believe that this is the most plausible scenario: 1) space mining is very profitable; 2) humans cannot survive for long periods of time in outer space limiting the prospects for human space colonization (HSC), and 3) automation is already a leading trend on Earth. Crewed missions will have an ancillary function, while machines or human/machine avatars will ‘inhabit’ other celestial bodies, in order to pursue economic enterprises and progress scientific discovery. We also propose some considerations on the speculative hypothesis, elaborated by a few leading futurists, that the development of machine-based learning Artificial Intelligence would lead to the so-called Singularity. In relation to this scenario, we argue that fully automated space colonization (FASC) could be a solution to prevent unwanted side effects of the Singularity, such as competition for resources between humankind and a hostile Artificial Intelligence.

Male‐mediated prenatal loss can provide greater reproductive benefits to males than infanticide; compared to infanticide, male‐mediated prenatal loss may be more prevalent and of greater role in mammalian species than thought

Male‐mediated prenatal loss: Functions and mechanisms. Matthew N. Zipple et al. Evolutionary Anthropology: Issues, News, and Reviews, April 6 2019. https://doi.org/10.1002/evan.21776

ABSTRACT: Sexually selected infanticide has been the subject of intense empirical and theoretical study for decades; a related phenomenon, male‐mediated prenatal loss, has received much less attention in evolutionary studies. Male‐mediated prenatal loss occurs when inseminated or pregnant females terminate reproductive effort following exposure to a nonsire male, either through implantation failure or pregnancy termination. Male‐mediated prenatal loss encompasses two sub‐phenomena: sexually selected feticide and the Bruce effect. In this review, we provide a framework that explains the relationship between feticide and the Bruce effect and describes what is known about the proximate and ultimate mechanisms involved in each. Using a simple model, we demonstrate that male‐mediated prenatal loss can provide greater reproductive benefits to males than infanticide. We therefore suggest that, compared to infanticide, male‐mediated prenatal loss may be more prevalent in mammalian species and may have played a greater role in their social evolution than has previously been documented.

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Bruce Effect in Wikipedia:

Evolutionary benefits

Males

When given the opportunity, male mice tend to direct their urine in the female’s direction.[23] This allows males to improve their fitness success by “sabotaging” the pregnancy of a male competitor,[3] and more quickly returning the female to estrus.[24] The Bruce effect can also aid in maintaining social status, with dominant males leaving more urinal scent markings,[25] and so blocking the pregnancies initiated by subordinate males.

Females

Females can control their likelihood of terminating pregnancy by pursuing or avoiding novel male contact during their most susceptible periods.[26] In this way, females can exert a post-copulatory mate choice, reserving their reproductive resources for the highest-quality male. Certainly, females are more likely to seek proximity to dominant males.[26] In many rodent species, males kill unrelated young; pregnancy block may avoid the wasted investment of gestating offspring likely to be killed at birth.[5][27] The Bruce effect is most common in polygynous rodent species, for which the risk of infanticide is highest.[28]

The mu-opioid system can influence higher-level cognitive function via modulation of valuation & motivation, influencing decision making & cognitive control by increasing the subjective value of reward & reducing aversive arousal

The role of the opioid system in decision making and cognitive control: A review. Henk van Steenbergen, Marie Eikemo, Siri Leknes. Cognitive, Affective, & Behavioral Neuroscience, April 8 2019. https://link.springer.com/article/10.3758/s13415-019-00710-6

Abstract: The opioid system regulates affective processing, including pain, pleasure, and reward. Restricting the role of this system to hedonic modulation may be an underestimation, however. Opioid receptors are distributed widely in the human brain, including the more “cognitive” regions in the frontal and parietal lobes. Nonhuman animal research points to opioid modulation of cognitive and decision-making processes. We review emerging evidence on whether acute opioid drug modulation in healthy humans can influence cognitive function, such as how we choose between actions of different values and how we control our behavior in the face of distracting information. Specifically, we review studies employing opioid agonists or antagonists together with experimental paradigms of reward-based decision making, impulsivity, executive functioning, attention, inhibition, and effort. Although this field is still in its infancy, the emerging picture suggests that the mu-opioid system can influence higher-level cognitive function via modulation of valuation, motivation, and control circuits dense in mu-opioid receptors, including orbitofrontal cortex, basal ganglia, amygdalae, anterior cingulate cortex, and prefrontal cortex. The framework that we put forward proposes that opioids influence decision making and cognitive control by increasing the subjective value of reward and reducing aversive arousal. We highlight potential mechanisms that might underlie the effects of mu-opioid signaling on decision making and cognitive control and provide directions for future research.

Keywords: Opioid system Cognitive control Decision making Executive function Value-based choice Reward Drugs Mu-opioid receptors Affect Mood Morphine Hedonic states

We see our past good deeds as more revealing of our present self than our past bad deeds, & we make inferences about our present personality from positive past behaviors, but not from negative ones; it is different with the others

Andreas Steimer, André Mata, and Cláudia Simão (2019). Ascribing Meaning to the Past: Self–Other Differences in Weighing Good and Bad Deeds. Social Cognition: Vol. 37, No. 2, pp. 174-196. https://doi.org/10.1521/soco.2019.37.2.174

Abstract: In three studies, this research found evidence for self-serving tendencies and a self–other asymmetry in the way people ascribe meaning to past behavior: Participants saw their past good deeds as more revealing of their present self than their past bad deeds (Studies 1–2), and they made inferences about their present personality from positive past behaviors, but not from negative ones (Study 3). In contrast, participants perceived the past behavior of others as diagnostic of their present personality (Study 2), and they made inferences about others' present traits from that behavior (Study 3), regardless of whether it was positive or negative. In support of a motivational account, we also found evidence for moderated mediation of our effect (Study 2), such that the valence effect on ascribing meaning to the past was mediated by desirability only when self-relevance was high (i.e., for the self), not when it was low (i.e., for others). Implications of this self–other asymmetry are discussed.

KEYWORDS: meaning, autobiographic memory, person memory, motivated reasoning, self–other differences, belief updating, true self

Testing the potential of 50 kHz rat calls as a species-specific rat attractant for pest control

Testing the potential of 50 kHz rat calls as a species-specific rat attractant. Nicola B. Davidson, Jane L. Hurst. PLOS, April 8, 2019. https://doi.org/10.1371/journal.pone.0211601

Abstract: The control of mammalian pests relies heavily on the use of pesticides that are often avoided and are not species-specific. These problems are particularly acute for pesticides used to control rats (Rattus spp.). The efficacy and targeting of control could be improved by attracting animals to control measures using species-specific cues. One cue that has the potential to attract rats is the 50 kHz calls they emit in positive social situations. Here we test the potential of these rat calls as a species-specific attractant by examining the response of laboratory rats (Rattus norvegicus; n = 48) and non-target bank voles (Myodes glareolus; n = 16) to 50 kHz calls from either sex in a compartmentalised laboratory arena. Sounds of rat movement and white noise acted as control treatments, with each sound tested against a silent control in the opposite side of the arena. When sound cues were played above an empty bait box, rats were attracted to spend time close to 50 kHz rat calls, climbing on top of boxes, regardless of the sex of subject or caller. When either 50 kHz rat calls or rat movement sounds were played inside an empty bait box, rats of both sexes spent 3–4 fold more time inside boxes and visited more frequently. Rats were not attracted by intermittent white noise. Bank voles were neither attracted to, nor avoided, 50 kHz rat calls played inside empty bait boxes. Our findings show that 50 kHz rat calls are an effective attractant for rats of both sexes under laboratory conditions, while not attracting non-target bank voles. These calls are strong candidates for providing a species-specific lure that may be attractive even in the absence of food bait, but further trials will be needed to assess their efficacy under field conditions.