Monday, November 23, 2020

Regional and network neural activity reflect men’s preference for greater socioeconomic status during impression formation

Regional and network neural activity reflect men’s preference for greater socioeconomic status during impression formation. Denise M. Barth, Bradley D. Mattan, Tzipporah P. Dang & Jasmin Cloutier. Scientific Reports volume 10, Article number: 20302. Nov 20 2020. https://www.nature.com/articles/s41598-020-76847-z

Abstract: Evidence from social psychology suggests that men compared to women more readily display and pursue control over human resources or capital. However, studying how status and gender shape deliberate impression formation is difficult due to social desirability concerns. Using univariate and multivariate fMRI analyses (n = 65), we examined how gender and socioeconomic status (SES) may influence brain responses during deliberate but private impression formation. Men more than women showed greater activity in the VMPFC and NAcc when forming impressions of high-SES (vs. low-SES) targets. Seed partial least squares (PLS) analysis showed that this SES-based increase in VMPFC activity was associated with greater co-activation across an evaluative network for the high-SES versus low-SES univariate comparison. A data-driven task PLS analysis also showed greater co-activation in an extended network consisting of regions involved in salience detection, attention, and task engagement as a function of increasing target SES. This co-activating network was most pronounced for men. These findings provide evidence that high-SES targets elicit neural responses indicative of positivity, reward, and salience during impression formation among men. Contributions to a network neuroscience understanding of status perception and implications for gender- and status-based impression formation are discussed.


Discussion

Across complementary univariate and multivariate analyses, the present findings reveal consistent evidence of greater sensitivity to status (viz., SES) in men than in women. In line with previous findings6,28, we observed greater activity in brain regions indexing positive evaluations of others26 and social reward/salience (e.g., NAcc, amygdala) as men (but not women) formed impressions of high-SES (vs. low-SES) faces. Seed PLS analyses revealed that preferential responses to high (vs. low) SES in the VMPFC were associated with greater co-activation in contrast images reflecting high SES > low SES within an extended network involved in person evaluation and mentalizing, including the precuneus, temporoparietal junction, insula, and orbitofrontal cortex. This co-activation pattern was similar for women and men, suggesting that despite a greater VMPFC preference for high SES in men, both genders show similar patterns of functional connectivity when they do show a pro-high-SES bias in the VMPFC. Beyond our focal regions of interest involved in person evaluation, an exploratory task PLS analysis revealed a coordinated network of brain regions that was sensitive to high-SES (vs. low-SES) faces. Again, this pattern was only reliably observed for men in our sample. The functional network emerging from these analyses is consistent with greater relevance and/or engagement with status cues in men. Taken together, the findings provide evidence that high versus low SES is associated with neural responses indicative of positivity, reward, and salience during impression formation for men. The present findings are noteworthy for their contribution to a network neuroscience understanding of status perception but also for their implications regarding how gender and status interact to shape our impressions of others. We elaborate on these implications in separate sections below. Additionally, by examining both target and perceiver gender, this work provides greater representation in samples than is often used for psychophysiological studies and avoids the potential pitfall of assuming that women respond to status in the same way that men do66. Indeed, as the present and previous work suggest, this is only sometimes the case.

Toward a network neuroscience approach to social hierarchy perception

The present study is among the first to use a multivariate brain network approach to investigate status-based impression formation. This data-driven approach revealed a functional brain network responsive to perceiving high-SES compared to low-SES people, particularly in men. This network shows considerable overlap with a previously identified set of regions involved in status-based attention6,67 and more broadly with networks believed to support salience detection60,62 and attention61,62. However, the observed co-activation network extended beyond these core networks, possibly implicating broader domain-general networks supporting focused task engagement62,63,64,65. Complementing our ROI approach, which focused on brain regions previously shown to support status-based evaluations6,28, the preferential involvement of this large brain network was also driven primarily by men in our sample (see Fig. 5). Taken together, these findings suggest that men may be especially engaged when forming impressions of high-SES people and that these impressions are likely positive14.

It is worth noting that the inferior parietal cortex emerged as one component of the status-based attention network identified through task PLS analysis. This region has been implicated in computing social distances68,69,70,71,72, showing greater activity for difficult comparisons between two closely ranked individuals compared to easy comparisons between very differently ranked individuals71. The involvement of the inferior parietal cortex in the SES-based functional network suggests that men in our sample may dedicate greater attention to differentiating SES when forming impressions of others, particularly when those individuals are high in SES. This interpretation would be consistent with findings from the human and animal literature that high-status (vs. low-status) individuals more readily attract and/or re-direct attention6,73,74,75,76 and are more easily remembered76.

Implications for status and gender of the perceiver

One key takeaway in the present study is that the participant’s gender consistently altered sensitivity to perceived SES. In multiple regions thought to support status-based evaluations6,25,28, men more reliably showed neural responses that were more indicative of positive impressions for high- versus low-status targets. Men also showed greater coordination for increasing target SES in an extended set of regions implicated in salience, attention, and task engagement as discussed in the preceding section. In other words, men more than women showed evidence of positive evaluations and more deliberative engagement with high-SES faces during impression formation. This finding is consistent with evolutionary psychological accounts suggesting that men more readily display, attend to, and/or pursue higher status18,77,78.

Notably, the effect of perceiver gender on neural responses to target SES was not further modulated by target gender. Based in part on predictions derived from theories of sexual selection19, it has been argued that women and men may prefer different dimensions of status, both for themselves77,78 and for potential heterosexual mates19,20,79. Despite some support for this theory in the behavioral literature, it receives little support from the extant albeit sparse neuroimaging literature on gender and status36. One important caveat is that no fMRI study to date has explicitly invoked a context relevant to mating.

Implications for status and gender in person perception

Operationalizing target status

Status can be conveyed along multiple dimensions ranging from commonly studied attributes like dominance36 and finances23,24,80 to social categories such as race21,22,81 and gender36. One important aspect of this study is its focus on SES instead of dominance, which has perhaps received greater attention so far in neuroimaging studies of gender in hierarchical contexts36. As a measure of social rank, SES comprises an individual’s standing in terms of education, income, and occupational prestige82. Although SES may convey dominance in some contexts, these two constructs are not the same6,83. Accordingly, neural responses to perceived dominance may not reflect responses to status when it is operationalized in terms of SES. Indeed, previous work suggests that VMPFC responses to high status depend on the dimension of status in question, with greater responses for high moral status than for high financial status23,24.

In addition to the dimension of status in question, it is also important to consider the means by which status is conveyed. In the present study, status was conveyed through colored cues previously paired with high or low SES. This approach is particularly important for neuroimaging studies of status due to potential confounds that exist in more naturalistic and subtle cues of status such as facial cues84 and clothing81,85,86,87. For example, clothing can shape impressions of dominance85, competence86,87, and attractiveness88, all of which are imperfectly tied to perceptions of status83. This is important for neuroimaging studies of status for two reasons. First, using such cues makes it difficult to distinguish whether purported effects of social rank may instead be due to related but non-equivalent attributes such as competence. Second, this problem would be compounded when comparing the perception of two groups that stereotypically differ in terms of competence87. The present study largely bypasses these limitations by relying on ascribed SES knowledge through color assignment rather than clothing or facial expressions.

Absence of effects of target gender

Although the gender of perceivers shaped neural responses to target status during impression formation, these responses did not differ based on the gender of targets. This is noteworthy for a few reasons. First, participants did explicitly rate women are more likeable than men after scanning, suggesting that they did attend to gender to some extent. Additionally, previous work has revealed distinct neural correlates of target gender, regardless of whether gender is explicitly processed36,89. Given the relative salience of social category cues such as gender90,91, we anticipated that gender might interact with target status. Indeed, Marsh and colleagues36 observed greater responses in the VMPFC and right amygdala for increasingly dominant body postures of only the woman targets. However, as previously mentioned, the fact that status was based on different dimensions (SES vs. dominance) and antecedents (perceptual attributes vs. person knowledge) may explain these differences. Furthermore, neuroimaging work examining status-based impression formation in the presence of another salient social category (viz., race) also only found effects of status21,22. One possibility is that participants disregarded initial impressions based on gender information by focusing on the available status knowledge to form more individuated impressions92.

The absence of effects of target gender is also noteworthy from the perspective of some proposals arising from evolutionary psychology. Due in part to a lower minimal male investment in child-rearing93, evolutionary psychologists argue that males were frequently engaged in ancestral conflicts within and between groups, resulting in greater natural selection of physical and psychological characteristics associated with dominance in males than in females18. This relationship between sex and social hierarchy cues may also extend to social constructions such as the clothes we wear. For example, previous work has shown that men wearing high-status attire are more readily attended94 and rated as more competent87 than women wearing high-status attire. In contrast with this previous work, the present study showed no unique effects of SES for faces depicting men compared to women. One possibility is that conveying status through person knowledge rather than appearance eliminates potential gender bias in how status shapes social attention and evaluations6.

Alternative interpretation

Prior to concluding, it is worth considering an alternative interpretation of the present work. Given that the impression formation task did not include a control task condition, one could argue that our findings are not related to the status information ascribed to each target during impression formation. In this perspective, one could imagine obtaining similar findings if the faces of women and men were grouped based on other social information than social status such as their preference for different kinds of food. If so, then our findings might mean that men are more sensitive than women to social information in general rather than social status, per se.

Notwithstanding existing research suggesting that, in some instances, women may be more sensitive to social information than men95,96,97, we believe it is more parsimonious to focus our interpretation in the context of status sensitivity, rather than sensitivity to social information more generally, for three reasons. (1) Given that the face stimuli were equated across various dimensions and counterbalanced across participants within gender, we think it would be prudent not to over-generalize our findings to other social information. (2) The present findings are consistent with the literature suggesting greater status-driven perception and behaviors in men10,14,15,16,17,18,98. (3) Assuming that men were more sensitive to social information in general, it is unclear why men didn’t also show greater neural sensitivity to perceived gender, a dimension that has demonstrable biological and psychological relevance as a function of perceiver gender19,20. The present study was focused primarily on SES as the perceived status dimension, finding evidence of greater neural sensitivity to high (vs. low) SES in men compared to women. Importantly, SES is but one possible dimension of social status, being composed of subcomponents (e.g., income, education, occupational prestige) that may or may not elicit the same kinds of evaluations6,28,83. Other social hierarchies that have been studied using fMRI include hierarchies based on dominance/ability/competence31,99, power80,100, and moral character23,24. With few exceptions23,24, these studies have focused on just one hierarchy dimension and often just one gender, usually men. In general, these studies frequently find the VMPFC and NAcc are responsive to high-ranking individuals. Other work by Kumaran and colleagues suggests that the VMPFC in particular may be implicated in updating social hierarchy knowledge in hierarchies involving the self100. However, it is unclear whether these effects are similarly driven by men as they were for SES in the present study. In future research, it will be important to replicate and extend the present work to determine whether men also show greater neural sensitivity to high status compared to women for other status dimensions as well as for social dimensions that are potentially ordinal but not frequently used to delineate hierarchies (e.g., age).

In sum, we believe our present findings can be interpreted as a gender-specific differential in sensitivity to perceived status. However, we do not believe that men’s greater sensitivity to SES in this study precludes the possibility that women (or men) might be more responsive to other social information in other contexts. For example, it is possible that subsequent studies may uncover a preference in women for other dimensions of status such as communal/moral character23,24,77 or that women may value high-SES individuals more than men in certain contexts. These questions among others are ripe for future inquiry and consistent with recent calls to explore how perceiver gender may differentially shape sensitivity to other dimensions of social information66. We hope that this study will pave the way for future work exploring gender differences in sensitivity to different forms of social information.

We investigate how a person’s happiness is affected by the incomes of her neighbours and coworkers: Workplace rank matters much more than neighbourhood rank

The effects of neighbourhood and workplace income comparisons on subjective wellbeing. Shakked Noy, Isabelle Sin. Journal of Economic Behavior & Organization, November 23 2020. https://doi.org/10.1016/j.jebo.2020.11.008

Rolf Degen's take: https://twitter.com/DegenRolf/status/1330877507931938818

Abstract: We investigate how a person’s happiness is affected by the incomes of her neighbours and coworkers. Using an unprecedentedly rich combination of administrative and survey data, we establish two central results. First, a person’s happiness is sensitive to her ordinal rank within her peer income distribution: people are happier the higher their income rank. Second, workplace rank matters much more than neighbourhood rank. We confirm that our results reflect a causal effect of peer income by implementing sensitivity analyses, identifying off changes in peer income over time for immobile people, exploiting plausibly exogenous moves between workplaces triggered by mass layoffs, and testing for the effects of unobservable group-level confounders.

Keywords: Subjective wellbeingIncome comparisonsRelative income

JEL D63I31J31


We may have been looking for a lawfulness in human behavior that exists only in our minds; there are no specific non-verbal behavioral signals that accompany lying or deceitful behavior

Research on Nonverbal Signs of Lies and Deceit: A Blind Alley. Tim Brennen and Svein Magnussen. Front. Psychol., Nov 2020, doi: 10.3389/fpsyg.2020.613410

Rolf Degen's take: https://twitter.com/DegenRolf/status/1330870990402973697

Research on the detection of lies and deceit has a prominent place in the field of psychology and law with a substantial research literature published in this field of inquiry during the last five to six decades (Vrij, 2000(Vrij, , 2008Vrij et al., 2019). There are good reasons for this interest in lie detection. We are all everyday liars, some of us more prolific than others, we lie in personal and professional relationships (Serota et al., 2010;Serota & Levine, 2015;Halevy et al., 2014;Verigin et al., 2019), and lying in public by politicians and other public figures has a long and continuing history (Peters, 2015). However, despite the personal problems that serious everyday lies may cause and the human tragedies political lies may cause, it is lying in court that appears to be the principle motivation for the scientific interest in lie detection.Lying in court is a threat to fair trials and the rule of law. Lying witnesses may lead to the exoneration of guilty persons or to the conviction of innocent ones. In the US it is well documented that innocent people have been convicted because witnesses were lying in court (Garrett, 2010(Garrett, , 2011www.innocenceproject.com). In evaluating the reliability and the truthfulness of a testimony, the court considers other evidence presented to the court, the known facts about the case and the testimonies by other witnesses. Inconsistency with the physical evidence or the testimonies of other witnesses might indicate that the witness is untruthful, or it may simply reflect the fact that the witness has observed, interpreted, and later remembered the critical events incorrectly --normal human errors all too well known in the eyewitness literature (Loftus, 2005;Wells & Loftus, 2013;Howe & Knott, 2015).When the facts of the case are not well known, witness testimonies, including the testimony from alleged victims, may be critical to a verdict, and these testimonies are sometimes from witnesses who hold a personal stake in the case and shun self-incriminating statements. In many countries, a witness lying in court risks being charged with perjury -the accused typically does not risk such a reaction -but there are still cases where witnesses lie. In such cases, when there is a possibility that one or more of the witnesses are lying and the court's verdict depends upon the perceived credibility of the witnesses, the issue arises of distinguishing between lying and truthful witnesses. Is it possible to identify liars versus truth tellers based on the non-verbal signals transmitted by the sender?

...

We may have been looking for a lawfulness in human behavior that exists only in our minds. Is the rational course simply to drop this line of research? We believe it is. The creative studies carried out during the last few decades have been important in showing that psychological folklore, the ideas we share about behavioral signals of lies and deceit are not correct. This debunking function of science is extremely important. But we now have sufficient evidence that there are no specific non-verbal behavioral signals that accompany lying or deceitful behavior. We can safely recommend that courts disregard such behavioral signals when appraising the credibility of victims, witnesses and suspected offenders. For psychology and law researchers it may be time to move on.

Research on the detection of lies and deceit has a prominent place in the field of psychology and law with a substantial research literature published in this field of inquiry during the last five to six decades (Vrij, 2000(Vrij, , 2008Vrij et al., 2019). There are good reasons for this interest in lie detection. We are all everyday liars, some of us more prolific than others, we lie in personal and professional relationships (Serota et al., 2010;Serota & Levine, 2015;Halevy et al., 2014;Verigin et al., 2019), and lying in public by politicians and other public figures has a long and continuing history (Peters, 2015). However, despite the personal problems that serious everyday lies may cause and the human tragedies political lies may cause, it is lying in court that appears to be the principle motivation for the scientific interest in lie detection. Lying in court is a threat to fair trials and the rule of law. Lying witnesses may lead to the exoneration of guilty persons or to the conviction of innocent ones. In the US it is well documented that innocent people have been convicted because witnesses were lying in court (Garrett, 2010(Garrett, , 2011www.innocenceproject.com). In evaluating the reliability and the truthfulness of a testimony, the court considers other evidence presented to the court, the known facts about the case and the testimonies by other witnesses. Inconsistency with the physical evidence or the testimonies of other witnesses might indicate that the witness is untruthful, or it may simply reflect the fact that the witness has observed, interpreted, and later remembered the critical events incorrectly --normal human errors all too well known in the eyewitness literature (Loftus, 2005;Wells & Loftus, 2013;Howe & Knott, 2015).When the facts of the case are not well known, witness testimonies, including the testimony from alleged victims, may be critical to a verdict, and these testimonies are sometimes from witnesses who hold a personal stake in the case and shun self-incriminating statements. In many countries, a witness lying in court risks being charged with perjury -the accused typically does not risk such a reaction -but there are still cases where witnesses lie. In such cases, when there is a possibility that one or more of the witnesses are lying and the court's verdict depends upon the perceived credibility of the witnesses, the issue arises of distinguishing between lying and truthful witnesses. Is it possible to identify liars versus truth tellers based on the non-verbal signals transmitted by the sender?

...

We may have been looking for a lawfulness in human behavior that exists only in our minds. Is the rational course simply to drop this line of research? We believe it is. The creative studies carried out during the last few decades have been important in showing that psychological folklore, the ideas we share about behavioral signals of lies and deceit are not correct. This debunking function of science is extremely important. But we now have sufficient evidence that there are no specific non-verbal behavioral signals that accompany lying or deceitful behavior. We can safely recommend that courts disregard such behavioral signals when appraising the credibility of victims, witnesses and suspected offenders. For psychology and law researchers it may be time to move on.

Sexual Minorities: Increased hours per day on Twitter and the greater likelihood of making downward social comparisons were the primary social media behaviors

A Comparison of Social Media Behaviors Between Sexual Minorities and Heterosexual Individuals. Sierra Kaiser  et al. Computers in Human Behavior, November 23 2020, 106638. https://doi.org/10.1016/j.chb.2020.106638

Rof Degen's take: https://twitter.com/DegenRolf/status/1330755397087621122

Highlights

• Increased hours per day on Twitter and the greater likelihood of making downward social comparisons were the primary social media behaviors associated with the sexual minority group.

• Sexual minority groups, who are already at higher risk for depression and suicide, may benefit from being informed on the possible contribution of excessive social media use on mental health and differing ways to decrease use.

• By aiding sexual minorities in their conscious awareness of their social media use, efforts may be made to help deter the negative psychological effects that is associated with prolonged social media exposure.

Abstract

Introduction: This study’s aim was to identify key differences in social media behaviors of sexual minorities compared to heterosexuals. Importantly, identifying which social media behaviors are more prevalent for sexual minorities helps understand online behavioral differences and promote psychological well-being.

Method: Participants were recruited online (N = 1,294) indicating use of Facebook or Twitter. They completed validated psychosocial questionnaires and responded to questions regarding specific social media behaviors. Univariate comparisons assessed differences in social media behaviors between the sexual minority group (n = 178) and the heterosexual group (n = 1,116). A stepwise binary logistic regression model identified the specific social media behaviors that were most associated with the sexual minority group.

Results: The univariate comparisons identified many differences in social media behavior between the sexual minority and heterosexual groups. Based on the multivariate analyses, the key social media behaviors most associated with the sexual minority group included more hours on Twitter and a higher likelihood of downward social comparisons.

Conclusion: Due to the pervasiveness of social media, potentially negative impacts associated with the social media behaviors of sexual minorities should be further examined. Additionally, positive outcomes to social media behaviors should also be assessed to promote healthier social media use among sexual minorities.

Keywords: Sexual MinorityLGBQSocial MediaDownward Social Comparisons


Sunday, November 22, 2020

The preference for music genres did not contribute to the happiness of any country; happiness increased with lesser Homicide rates and higher Substance abuse

Kapoor, Ishaan, Junmoni Borgohain, and Manas K. Mandal. 2020. “Can Music Genre Determine the Happiness of a Country?.” PsyArXiv. November 22. doi:10.31234/osf.io/f8eur

Abstract: Music not only serves as an important source in regulating moods but also transcends itself in impacting the happiness of individuals. However, it is not well documented that explores what specific music genre(s) are preferred in countries, whether specific preferences affect happiness, and if moderators such as Suicide, Homicide, Substance abuse and Alcohol abuse interact with genres to determine happiness. To examine this, data were collected from secondary sources from Our World in Data repository and World Happiness Report and Google trends. It was found that the preference for music genres did not contribute to the happiness of any country. However, music genres such as Rap & RnB predicted Homicide, and EDM was associated with Substance abuse. At the same time, genres did not qualify significantly for explaining the variance observed in other moderating variables such as Suicide, Alcohol abuse and Homicide. Regression analysis revealed that happiness increased with lesser Homicide rates and higher Substance abuse


Does Self-rated Attractiveness Predict Women’s Preferences for Facial Masculinity? Data from an Arab Sample

Alharbi, Sarah A., Iris J. Holzleitner, Anthony J. Lee, Selahattin A. Saribay, and Benedict C. Jones. 2020. “Does Self-rated Attractiveness Predict Women’s Preferences for Facial Masculinity? Data from an Arab Sample.” PsyArXiv. November 18. doi:10.31234/osf.io/de4yu

Abstract: Because more attractive women may be better able to attract and/or retain masculine mates, many researchers have proposed that women who consider themselves to be more physically attractive will show stronger preferences for men displaying masculine facial characteristics. Empirical evidence for this putative association between women’s self-rated attractiveness and preference for facial masculinity has come almost entirely from studies of Western women. To investigate whether this pattern of results also occurs in a sample of non-Western women, we investigated the relationship between self-rated attractiveness and facial-masculinity preferences in a sample of Arab women (N = 281). By contrast with previous findings for Western women’s self-rated attractiveness, we observed no compelling evidence that Arab women who considered themselves to be more attractive showed stronger preferences for masculine men. This result suggests that associations between self-rated attractiveness and masculinity preferences might be somewhat culture specific, potentially reflecting cultural differences in typical mating strategies.


Saturday, November 21, 2020

Sexual selection appears to have shaped the acoustic signals of diverse species, including humans; deep, resonant vocalizations in particular may function in attracting mates and/or intimidating same-sex competitors

Linking human male vocal parameters to perceptions, body morphology, strength and hormonal profiles in contexts of sexual selection. Christoph Schild et al. Nov 2020. http://www.larspenke.eu/pdfs/Schild_et_al_in_press_-_Linking_human_male_voice_characteristics.pdf

Abstract: Sexual selection appears to have shaped the acoustic signals of diverse species, including humans. Deep, resonant vocalizations in particular may function in attracting mates and/or intimidating same-sex competitors. Evidence for these adaptive functions in human males derives predominantly from perception studies in which vocal acoustic parameters were manipulated using specialist software. This approach affords tight experimental control but provides little ecological validity, especially when the target acoustic parameters vary naturally with other parameters. Furthermore, such experimental studies provide no information about what acoustic variables indicate about the speaker – that is, why attention to vocal cues may be favored in intrasexual and intersexual contexts. Using voice recordings with high ecological validity from 160 male speakers and biomarkers of condition, including baseline cortisol and testosterone levels, body morphology and strength, we tested a series of pre-registered hypotheses relating to both perceptions and underlying condition of the speaker. We found negative curvilinear and negative linear relationships between male fundamental frequency (fo) and female perceptions of attractiveness and male perceptions of dominance. In addition, cortisol and testosterone negatively interacted in predicting fo, and strength and measures of body size negatively predicted formant frequencies (Pf). Meta-analyses of the present results and those from two previous samples confirmed that fo negatively predicted testosterone only among men with lower cortisol levels. This research offers empirical evidence of possible evolutionary functions for attention to men’s vocal characteristics in contexts of sexual selection.

Check also Voice Pitch Seems A Valid Indicator of One’s Unfaithfulness in Committed Relationships:

Voice Pitch – A Valid Indicator of One’s Unfaithfulness in Committed Relationships? Christoph Schild, Julia Stern, Lars Penke & Ingo Zettler. Adaptive Human Behavior and Physiology, Oct 16 2020. https://www.bipartisanalliance.com/2020/10/voice-pitch-seems-valid-indicator-of.html


How Cheating in Romance Might Signal Positive Well-Being in Adolescents, favoring adolescents’ personal growth, because of the need to explore new sensations and feelings that arise during this period

The Relationship Between the Motivation to Commit Infidelity and Negative Affect and Self-Esteem: How Cheating in Romance Might Signal Positive Well-Being in Adolescents. Ana M. Beltrán-Morillas et al. Psychological Reports, November 16, 2020. https://doi.org/10.1177/0033294120973947

Abstract: Infidelity occurs in adult romantic relationships quite often; however, little is known about this relational phenomenon in the adolescent stage, despite its being a surprisingly common behavior. Through a correlational study, we set out to examine how the various documented motivations to engage in an act of infidelity are associated with negative emotional responses, self-esteem, and psychological well-being. In a sample of Spanish adolescents (N = 346 [Mage = 15.71, SD = 1.27; range from 13 to 19]), results showed that committing an act of infidelity due to sexual or emotional dissatisfaction (vs. neglect and anger) is related to higher levels of psychological well-being by undermining negative affect, thereby increasing the levels of self-esteem. The discussion of the findings emphasizes that infidelity could favor adolescents’ personal growth, because of the need to explore new sensations and feelings that arise during this period.

Keywords: Adolescence, infidelity, negative affect, psychological well-being, self-esteem


At least 89 nonhuman primate species eat meat; the main importance of meat is probably as a source of vitamins, minerals, and micronutrients

Meat eating by nonhuman primates: A review and synthesis. David P. Watts. Journal of Human Evolution, Volume 149, December 2020, 102882. https://doi.org/10.1016/j.jhevol.2020.102882

Highlights

• At least 89 nonhuman primate species representing 39 genera and 12 families eat meat.

• Birds are the most common prey taxon, followed by reptiles, amphibians, mammals, and fish.

• Most primates eat meat rarely, if at all, but meat sometimes provides substantial immediate energy and protein gains.

• The main importance of meat is probably as a source of vitamins, minerals, and micronutrients.

• Chimpanzees eat more meat than all other nonhuman primates, but much less than African hunter-gatherers.

• Nonhuman primates only hunt prey much smaller than themselves. Only some capuchins and some chimpanzees use tools to assist in prey capture.

Abstract: Most nonhuman primates prey on vertebrates. Meat-eating, defined as ingestion of vertebrate tissue, occurs in 12 families, ≥39 genera, and ≥89 species. It is most common in capuchins (Cebus and Sapajus spp.), baboons (Papio spp.), bonobos (Pan paniscus), and chimpanzees (Pan troglodytes) and modestly common in blue monkeys (Cercopithecus mitis), callitrichids (Callithrix spp. and Saguinus spp.), and squirrel monkeys (Saimiri spp.). It is uncommon in other cercopithecines, rare in other haplorhines and in lemurs, and virtually absent in colobines. Birds are the prey class eaten by the most species (≥53), followed by reptiles (≥48), amphibians (≥38), mammals (≥35), and fish (≥7). Major hypotheses for the importance of meat eating are that it is (1) mainly an energy source, especially (1a) when plant-source foods (PSFs) with high energy return rates are scarce (energy shortfall hypothesis); (2) mainly a protein source; and (3) mainly a source of micronutrients scarce in PSFs. Meat eating bouts sometimes provide substantial energy and protein, and some chimpanzees gain substantial protein from meat monthly or annually. However, meat typically accounts for only small proportions of feeding time and of total energy and protein intake, and quantitative data are inconsistent with the energy shortfall hypothesis. PSFs and/or invertebrates are presumably the main protein sources, even for chimpanzees. Support is strongest for the micronutrient hypothesis. Most chimpanzees eat far less meat than recorded for hunter-gatherers, but the highest chimpanzee estimates approach the lowest for African hunter-gatherers. In fundamental contrast to the human predatory pattern, other primates only eat vertebrates much smaller than they are, tool-assisted predation is rare except in some capuchins and chimpanzees, and tool use in carcass processing is virtually absent. However, harvesting of small prey deserves more attention with reference to the archaeological and ethnographic record.

Keywords: PrimatesMeat eatingNutritionChimpanzeesCapuchinsBaboons