Saturday, August 7, 2021

Squirrel parkour

Acrobatic squirrels learn to leap and land on tree branches without falling. Nathaniel H. Hunt et al. Science  Aug 6 2021:Vol. 373, Issue 6555, pp. 697-700. DOI: 10.1126/science.abe5753

Squirrel parkour

Every day, there are acrobatic extravaganzas going on above our heads. Squirrels navigate remarkably complex and unpredictable environments as they leap from branch to branch, and mistakes can be fatal. These feats require a complex combination of evolved biomechanical adaptations and learned behaviors. Hunt et al. characterized the integration of these features in a series of experiments with free-living fox squirrels (see the Perspective by Adolph and Young). They found that the squirrels' remarkable and consistent success was due to a combination of learned impulse generation when assessing the balance between distance and branch flexibility and the addition of innovative leaps and landings in the face of increasingly difficult challenges.

Abstract: Arboreal animals often leap through complex canopies to travel and avoid predators. Their success at making split-second, potentially life-threatening decisions of biomechanical capability depends on their skillful use of acrobatic maneuvers and learning from past efforts. Here, we found that free-ranging fox squirrels (Sciurus niger) leaping across unfamiliar, simulated branches decided where to launch by balancing a trade-off between gap distance and branch-bending compliance. Squirrels quickly learned to modify impulse generation upon repeated leaps from unfamiliar, compliant beams. A repertoire of agile landing maneuvers enabled targeted leaping without falling. Unanticipated adaptive landing and leaping “parkour” behavior revealed an innovative solution for particularly challenging leaps. Squirrels deciding and learning how to launch and land demonstrates the synergistic roles of biomechanics and cognition in robust gap-crossing strategies.

Humans resist unequal distributions of goods in their social interactions, even if it requires foregoing personal gains—Study Finds A Causal Role of the Insula in Aversion to Social Inequity Via Lesion Evidence

Lesion Evidence for a Causal Role of the Insula in Aversion to Social Inequity. Felix Jan Nitsch, Hannah Strenger, Stefan Knecht, Bettina Studer. Social Cognitive and Affective Neuroscience, nsab098, August 6 2021.

Abstract: Humans resist unequal distributions of goods in their social interactions, even if it requires foregoing personal gains. Functional neuroimaging studies implicate the insula in this aversion to social inequity and in fairness-related decisions, but a causal contribution has not yet been established. We compared the responses of 30 patients with lesions to the insula on a multiple-trial version of the one-shot Ultimatum Game, a neuroeconomic social exchange paradigm where a sum of money is split between two players, to those of 30 matched patients with brain injuries sparing the insula. Insula lesion patients accepted offers of an unequal disadvantageous split significantly more often than comparison lesion patients. Computational modeling confirmed that this difference in choice behavior was due to decreased aversion to disadvantageous inequity following insula damage, rather than due to increased decision noise or non-consideration of inequity. Our results provide novel evidence that the insula is causally involved in aversion to inequity and in value-based choices in the context of social interactions.

Keywords: inequity aversion, insula, computational modeling, social decision-making, value-based choices

Politically partisan left-right online news echo chambers are real, but only a minority of approximately 5% of internet news users inhabit them; the continued popularity of mainstream outlets often preclude the formation of large partisan echo chambers

How Many People Live in Politically Partisan Online News Echo Chambers in Different Countries? Richard Fletcher, Craig T. Robertson, Rasmus Kleis Nielsen. Journal of Quantitative Description: Digital Media, Vol. 1 (2021). Aug 4 2021.

Abstract: Concern over online news echo chambers has been a consistent theme in recent debates on how people get news and information. Yet, we lack a basic descriptive understanding of how many people occupy bounded online news spaces in different countries. Using online survey data from seven countries we find that (i) politically partisan left-right online news echo chambers are real, but only a minority of approximately 5% of internet news users inhabit them, (ii) in every country covered, more people consume no online news at all than occupy partisan online echo chambers, and (iii) except for the US, decisions over the inclusion or exclusion of particular news outlets make little difference to echo chamber estimates. Differences within and between media systems mean we should be very cautious about direct comparisons between different echo chambers, but underlying patterns of audience overlap, and the continued popularity of mainstream outlets, often preclude the formation of large partisan echo chambers.

Keywords: echo chambers, selective exposure, algorithmic selection, news audiences, polarization

Check also  Users do not universally interpret high numbers of “likes” for messages congruent to their own attitudes as valid evidence for the public agreeing with them, especially if their interest in a topic is high:

Luzsa, R., & Mayr, S. (2021). False consensus in the echo chamber: Exposure to favorably biased social media news feeds leads to increased perception of public support for own opinions. Cyberpsychology: Journal of Psychosocial Research on Cyberspace, 15(1), Article 3.

And: Humans in specific instances are psychologically prepared to prioritize misinformation over truth to, inter alia, mobilize the ingroup against the outgroup & signal commitment to the group to fellow ingroup members

Petersen, Michael Bang, Mathias Osmundsen, and John Tooby. 2020. “The Evolutionary Psychology of Conflict and the Functions of Falsehood.” PsyArXiv. August 29.

And: Echo Chambers Exist! (But They're Full of Opposing Views). Jonathan Bright, Nahema Marchal, Bharath Ganesh, Stevan Rudinac. arXiv Jan 30 2020. arXiv:2001.11461.

And: The rise in the political polarization in recent decades is not accounted for by the dramatic rise in internet use; claims that partisans inhabit wildly segregated echo chambers/filter bubbles are largely overstated:
Deri, Sebastian. 2019. “Internet Use and Political Polarization: A Review.” PsyArXiv. November 6.

And Testing popular news discourse on the “echo chamber” effect: Does political polarisation occur among those relying on social media as their primary politics news source? Nguyen, A. and Vu, H.T. First Monday, 24 (5), 6. Jun 4 2019.

Check also
Why Smart People Are Vulnerable to Putting Tribe Before Truth. Dan M Kahan. Scientific American, Dec 03 2018.

Baum, J., Rabovsky, M., Rose, S. B., & Abdel Rahman, R. (2018). Clear judgments based on unclear evidence: Person evaluation is strongly influenced by untrustworthy gossip. Emotion,

The key mechanism that generates scientific polarization involves treating evidence generated by other agents as uncertain when their beliefs are relatively different from one’s own:

Scientific polarization. Cailin O’Connor, James Owen Weatherall. European Journal for Philosophy of Science. October 2018, Volume 8, Issue 3, pp 855–875.

Polarized Mass or Polarized Few? Assessing the Parallel Rise of Survey Nonresponse and Measures of Polarization. Amnon Cavari and Guy Freedman. The Journal of Politics,

Tappin, Ben M., and Ryan McKay. 2018. “Moral Polarization and Out-party Hate in the US Political Context.” PsyArXiv. November 2.

Forecasting tournaments, epistemic humility and attitude depolarization. Barbara Mellers, PhilipTetlock, Hal R. Arkes. Cognition,

Does residential sorting explain geographic polarization? Gregory J. Martin & Steven W. Webster. Political Science Research and Methods,

Liberals and conservatives have mainly moved further apart on a wide variety of policy issues; the divergence is substantial quantitatively and in its plausible political impact: intra party moderation has become increasingly unlikely:

Peltzman, Sam, Polarizing Currents within Purple America (August 20, 2018). SSRN:

Does Having a Political Discussion Help or Hurt Intergroup Perceptions? Drawing Guidance From Social Identity Theory and the Contact Hypothesis. Robert M. Bond, Hillary C. Shulman, Michael Gilbert. Bond Vol 12 (2018),

All the interactions took the form of subjects rating stories offering ‘ammunition’ for their own side of the controversial issue as possessing greater intrinsic news importance:

Perceptions of newsworthiness are contaminated by a political usefulness bias. Harold Pashler, Gail Heriot. Royal Society Open Science,

When do we care about political neutrality? The hypocritical nature of reaction to political bias. Omer Yair, Raanan Sulitzeanu-Kenan. PLOS,

Democrats & Republicans were both more likely to believe news about the value-upholding behavior of their in-group or the value-undermining behavior of their out-group; Republicans were more likely to believe & want to share apolitical fake news:

Pereira, Andrea, and Jay Van Bavel. 2018. “Identity Concerns Drive Belief in Fake News.” PsyArXiv. September 11.

In self-judgment, the "best option illusion" leads to Dunning-Kruger (failure to recognize our own incompetence). In social judgment, it leads to the Cassandra quandary (failure to identify when another person’s competence exceeds our own): The best option illusion in self and social assessment. David Dunning. Self and Identity,

People are more inaccurate when forecasting their own future prospects than when forecasting others, in part the result of biased visual experience. People orient visual attention and resolve visual ambiguity in ways that support self-interests: "Visual experience in self and social judgment: How a biased majority claim a superior minority." Emily Balcetis & Stephanie A. Cardenas. Self and Identity,

Can we change our biased minds? Michael Gross. Current Biology, Volume 27, Issue 20, 23 October 2017, Pages R1089–R1091.
Summary: A simple test taken by millions of people reveals that virtually everybody has implicit biases that they are unaware of and that may clash with their explicit beliefs. From policing to scientific publishing, all activities that deal with people are at risk of making wrong decisions due to bias. Raising awareness is the first step towards improving the outcomes.

People believe that future others' preferences and beliefs will change to align with their own:
The Belief in a Favorable Future. Todd Rogers, Don Moore and Michael Norton. Psychological Science, Volume 28, issue 9, page(s): 1290-1301,

Kahan, Dan M. and Landrum, Asheley and Carpenter, Katie and Helft, Laura and Jamieson, Kathleen Hall, Science Curiosity and Political Information Processing (August 1, 2016). Advances in Political Psychology, Forthcoming; Yale Law & Economics Research Paper No. 561. SSRN:
Abstract: This paper describes evidence suggesting that science curiosity counteracts politically biased information processing. This finding is in tension with two bodies of research. The first casts doubt on the existence of “curiosity” as a measurable disposition. The other suggests that individual differences in cognition related to science comprehension - of which science curiosity, if it exists, would presumably be one - do not mitigate politically biased information processing but instead aggravate it. The paper describes the scale-development strategy employed to overcome the problems associated with measuring science curiosity. It also reports data, observational and experimental, showing that science curiosity promotes open-minded engagement with information that is contrary to individuals’ political predispositions. We conclude by identifying a series of concrete research questions posed by these results.

Facebook news and (de)polarization: reinforcing spirals in the 2016 US election. Michael A. Beam, Myiah J. Hutchens & Jay D. Hmielowski. Information, Communication & Society,

The Partisan Brain: An Identity-Based Model of Political Belief. Jay J. Van Bavel, Andrea Pereira. Trends in Cognitive Sciences,

The Parties in our Heads: Misperceptions About Party Composition and Their Consequences. Douglas J. Ahler, Gaurav Sood. Aug 2017,

The echo chamber is overstated: the moderating effect of political interest and diverse media. Elizabeth Dubois & Grant Blank. Information, Communication & Society,

Processing political misinformation: comprehending the Trump phenomenon. Briony Swire, Adam J. Berinsky, Stephan Lewandowsky, Ullrich K. H. Ecker. Royal Society Open Science, published on-line March 01 2017. DOI: 10.1098/rsos.160802,

Competing cues: Older adults rely on knowledge in the face of fluency. By Brashier, Nadia M.; Umanath, Sharda; Cabeza, Roberto; Marsh, Elizabeth J. Psychology and Aging, Vol 32(4), Jun 2017, 331-337.

Stanley, M. L., Dougherty, A. M., Yang, B. W., Henne, P., & De Brigard, F. (2017). Reasons Probably Won’t Change Your Mind: The Role of Reasons in Revising Moral Decisions. Journal of Experimental Psychology: General.

Science Denial Across the Political Divide — Liberals and Conservatives Are Similarly Motivated to Deny Attitude-Inconsistent Science. Anthony N. Washburn, Linda J. Skitka. Social Psychological and Personality Science, 10.1177/1948550617731500.

Biased Policy Professionals. Sheheryar Banuri, Stefan Dercon, and Varun Gauri. World Bank Policy Research Working Paper 8113.

Dispelling the Myth: Training in Education or Neuroscience Decreases but Does Not Eliminate Beliefs in Neuromyths. Kelly Macdonald et al. Frontiers in Psychology, Aug 10 2017.

Individuals with greater science literacy and education have more polarized beliefs on controversial science topics. Caitlin Drummond and Baruch Fischhoff. Proceedings of the National Academy of Sciences, vol. 114 no. 36, pp 9587–9592, doi: 10.1073/pnas.1704882114,

Expert ability can actually impair the accuracy of expert perception when judging others' performance: Adaptation and fallibility in experts' judgments of novice performers. By Larson, J. S., & Billeter, D. M. (2017). Journal of Experimental Psychology: Learning, Memory, and Cognition, 43(2), 271–288.

Public Perceptions of Partisan Selective Exposure. Perryman, Mallory R. The University of Wisconsin - Madison, ProQuest Dissertations Publishing, 2017. 10607943.

The Myth of Partisan Selective Exposure: A Portrait of the Online Political News Audience. Jacob L. Nelson, and James G. Webster. Social Media + Society,

Echo Chamber? What Echo Chamber? Reviewing the Evidence. Axel Bruns. Future of Journalism 2017 Conference.

Fake news and post-truth pronouncements in general and in early human development. Victor Grech. Early Human Development,

Consumption of fake news is a consequence, not a cause of their readers’ voting preferences. Kahan, Dan M., Misinformation and Identity-Protective Cognition (October 2, 2017). Social Science Research Network,

Fake News & Ideological (a)symmetries in Perceptions of Media Legitimacy: Partisans are motivated to believe fake news & dismiss true news that contradicts their position as fake news

Harper, Craig A., and Thom Baguley. 2019. ““You Are Fake News”: Ideological (a)symmetries in Perceptions of Media Legitimacy” PsyArXiv. January 23. doi:10.31234/

Twitter: While partisan opinion leaders are certainly polarized, centrist/non-political voices are much more likely to produce the most visible information; & there is little evidence of echo-chambers in consumption
Mukerjee, Subhayan, Kokil Jaidka, and Yphtach Lelkes. 2020. “The Ideological Landscape of Twitter: Comparing the Production Versus Consumption of Information on the Platform.” OSF Preprints. June 23.

Contrary to this prediction, we found that moderate and uncertain participants showed a nonreciprocal attraction towards extreme and confident individuals:
Zimmerman, Federico, Gerry Garbulsky, Dan Ariely, Mariano Sigman, and Joaquin Navajas. 2020. “The Nonreciprocal and Polarizing Nature of Interpersonal Attraction in Political Discussions.” PsyArXiv. August 21.

Cross-Partisan Discussions on YouTube: Conservatives Talk to Liberals but Liberals Don't Talk to Conservatives. Siqi Wu, Paul Resnick. arXiv Apr 12 2021.

To quantify partisan audience bias, we developed a domain-level score by leveraging the sharing propensities of registered voters on a large Twitter panel; we found little evidence for the "filter bubble'' hypothesis 

Auditing Partisan Audience Bias within Google Search. Ronald E. Robertson et al. Proceedings of the ACM on Human-Computer Interaction - CSCW archive. Volume 2 Issue CSCW, November 2018, Article No. 148, doi: 10.1145/3274417.

Few people are actually trapped in filter bubbles. Why do they like to say that they are? Plus: Are your Google results really that different from your neighbor’s? Laura Hazard Owen. NiemanLab, Dec 07 2018.

UPDATED with later information

Young, Dannagal G. 2021. “Young and Miller, Political Communication in Oxford Handbook of Poli Psych 3rd Ed.” OSF Preprints. August 27. doi:10.31219/,

Exposure to partisan and centrist news websites – no matter if it is congenial or cross-cutting – does not enhance polarization; null effects are found among strong & weak partisans, & for Democrats & Republicans alike:

Wojcieszak, Magdalena, Sjifra E. de Leeuw, Ericka Menchen-Trevino, Seungsu Lee, Ke M. Huang-Isherwood, and Brian Weeks. 2021. “Wojcieszak Et Al No Polarization from Partisan News IJPP Forthcoming.” OSF Preprints. September 1 2021.

No support was found for the hypothesis that social media use contributed to the level of affective polarization; instead, it was the level of affective polarization that affected subsequent use of social media:

Affective polarization in the digital age: Testing the direction of the relationship between social media and users’ feelings for out-group parties. Maria Nordbrandt. New Media & Society, September 19, 2021.

The population is widely exposed to online false news; however, echo chambers are minimal, and the most avid readers of false news content regularly expose themselves to mainstream news sources

Zhang, Jiding and Moon, Ken and Veeraraghavan, Senthil K., Does Fake News Create Echo Chambers? (June 23, 2022). SSRN.

The impact of social media on beliefs or actual outcomes has been either non-existent or inconclusive; people who believe in conspiracies gravitate toward groups that espouse these

Processes of Persuasion and Social Influence in Conspiracy Beliefs. Dolores Albarracin. Current Opinion in Psychology, September 5 2022, 101463.

Abstract: If conspiracy beliefs were an individual process, no conspiracy theory would be alike. Instead, these beliefs are promoted by individuals or social groups through the media or informal channels of communication, leading to identical beliefs being espoused by different people and social groups. This paper reviews the role of the social influence as a basis for conspiracy beliefs and describes the role of legacy media, discussions with others, and social media, as well as the underlying informational and normative mechanisms. The role of trust is also considered, including how trust in science can increase vulnerability to conspiracy theories by opening audiences up to the influence of pseudo-scientists. Mitigating the impact of these influences will require research attention to processes that go beyond correction, elucidating the interpersonal consequences of corrections within contemporary information wars.

Found that anal sex had a much later age of initiation compared to oral and vaginal sex; anal sex is a less common and more sexually advanced behavior and may require greater preparation compared to oral and vaginal varieties

Roberts H, Clark A, Sherman C, Heitzeg MM, Hicks BM (2021) Age, sex, and other demographic trends in sexual behavior in the United States: Initial findings of the sexual behaviors, internet use, and psychological adjustment survey. PLoS ONE 16(8): e0255371.

Abstract: It remains unclear how the seemingly ubiquitous use of the internet impacts user’s offline personal relationships, particularly those that are romantic or sexual. Therefore, we conducted a national online survey to better understand the associations among internet use, sexual behavior, and adjustment called the Sexual Behaviors, Internet Use, and Psychological Adjustment Survey (SIPS). Here, we report patterns of sexual behavior in a sample of adults (N = 1987; ages 18–70) in the United States to establish its representativeness and consistency with similar recent surveys. We found age- and sex-related trends in oral, vaginal, and anal sex in terms of prevalence, frequency, number of partners, and age of initiation consistent with prior studies. We also detected differences in sexual behaviors based on relationship status and sexual orientation, but small and relatively few significant differences across racial and ethnic groups. The results confirm and expand upon trends identified in prior national surveys of sexual behavior, establishing the representativeness of the SIPS sample for use in future research examining the links among sexual behaviors and romantic relationships, internet use, and adjustment.


We sought to evaluate the representativeness of the SIPS sample—a national survey conducted to better understand relationships among sexual behavior, internet use, and psychological adjustment—by examining whether the rates and demographic trends in sexual behavior replicated prior estimates from similar national surveys. Sample estimates of the prevalence, frequency, number of partners, and age of initiation in oral, vaginal, and anal sex were broadly consistent with prior studies, as were subgroup analyses examining differences in sexual behavior associated with relationship status, sexual orientation, race, and ethnicity.

Trends associated with age and sex

Results for age and sex trends in the prevalence, frequency, number of partners, and age of initiation were consistent with and expand upon previous nationally representative online samples [12]. We replicated the finding of high rates of lifetime participation in oral and vaginal sex (>80%), and a much lower, but not trivial, rate of anal sex (<40%). As our subgroup analyses on sexual orientation revealed, this difference is largely attributable to the low proportion of homosexual men in an unselected national sample. This is to be expected in population samples, where rates of non-heterosexual orientation and male-male sexual behavior are relatively low, and heterosexual couples are more likely to choose to engage in oral and vaginal sex. For example, only 17.6% of respondents reported a non-heterosexual orientation in the current sample, and only 34.4% of respondents endorsing 100% heterosexual orientation reported ever having engaged in anal sex, whereas 61.7% of respondents endorsing 100% homosexual orientation reported engaging in anal sex. The lower levels of anal sex among heterosexual participants may be explained by the stigma associated with anal sex, for example, beliefs that anal sex is immoral or “dirty,” along with historical restrictions on activities such as sodomy and same-sex marriage [2728].

We also replicated prior findings that the frequency of these sexual behaviors was highest in middle adulthood [1229]. The associations between frequency of sex and age may be at least partially attributable to relationship status. That is, people in serious relationships tend to have more frequent sex than single people, and people tend to form more serious relationships in young and middle adulthood. For example, the average age of first marriage in the United States was 29 years old in 2020 [30]. The frequency of sex may also be influenced by fertility and intention to birth children, a process that must occur before menopause (typically, before ages 45–55 years old) [3132].

We also replicated prior findings that men reported a greater number of sexual partners than women throughout their lifetime [101220]. Men’s report of the number of sexual partners also exhibited higher variance than women’s report of the number of sexual partners. This was primarily due to a small proportion of men that reported an especially high number of sexual partners, increasing both the mean and variance of the number of sexual partners relative to women [33]. We also identified a considerably lower median value for the number of sexual partners compared to the mean value across gender, further illustrating the influence of the small proportion of respondents reporting a very high number of partners, with the effect being stronger in men compared to women. Further, in a study addressing why estimates of sexual partners are often higher in men than women, Mitchell et al. [34] found that men tend to estimate their number of sexual partners (often rounding up to numbers that end in 0 or 5) whereas women tend to count them, a reporting error which may have affected the point estimates in our sample.

We also found that anal sex had a much later age of initiation compared to oral and vaginal sex [18]. This is consistent with the lower prevalence rate of anal sex relative vaginal and oral sex. That is, anal sex is a less common and more sexually advanced behavior and may require greater preparation compared to oral and vaginal sex [35]. This may pose a barrier to populations with limited access to certain sexual wellness resources (i.e., lubrication).

Trends associated with relationship status, sexual orientation, race, and ethnicity

We also found that numerous aspects of sexual behavior varied by subgroups of relationship status, sexual orientation, race, and ethnicity. As oral, vaginal, or anal sex are all partnered behaviors, it follows that participating in ongoing romantic and sexual relationships facilitates access to potential sex partners, access that is more limited or at least not as readily available to people not participating in such relationships. This finding is in line with prior research, confirming that while single people may have greater opportunities for casual sex with a greater number of partners, people in a relationship have more frequent sex [1416]. Interestingly, people that reported being in a casual relationship(s) reported a higher frequency of sex and more sexual partners, though they constituted a small proportion of the sample.

Consistent with prior findings regarding sexual orientation, heterosexual and bisexual men reported higher rates of vaginal sex than homosexual men. This finding is easily understood via anatomical constraints, that is, vaginal sex is not possible in cisgender male-male partnerships. Further, homosexual males reported higher rates of anal sex than heterosexual and bisexual males. As discussed previously, the stigma surrounding anal sex may account for lower rates of anal sex in non-homosexual subgroups. We also found that bisexual respondents participated in a wide variety of sexual behavior and reported a particularly high frequency of sex and earlier age of sexual initiation compared to other sexual orientation groups. Similar trends were also observed for respondents that endorsed a mostly heterosexual or mostly homosexual orientation. Some prior work suggests that sexual minority groups have more liberal attitudes about sex compared to heterosexual people, that is, a greater acceptance of recreational sex, potentially contributing to an earlier age of sexual initiation and a higher frequency of sex [3637].

Results for racial differences in sexual behaviors were less consistent with prior findings. We did detect a significant difference for earlier ages of initiation for oral and vaginal sex for White and Black participants relative to Asian participants, and that Black participants reported more lifetime vaginal sex partners than White participants. Although the effects were small (Cohen’s d < .30), we did observe a trend for Black participants to report a higher frequency, more partners, and an earlier age of initiation for oral and vaginal sex than White and Asian participants as reported in prior studies [14152123]. The lack of significant differences could be due to a different design than most prior studies of general sexual behavior (i.e., our use of internet-based recruitment and survey methods assessing oral, vaginal, and anal sex separately). While Herbenick and colleagues [12] examined oral, vaginal, and anal sex trends in an online-based survey, they did not report on racial differences, which would have provided a useful comparison for the current study and allowed us to explore if racial differences in sexual behavior are smaller or less robust relative to factors such as relationship status and sexual orientation, or if racial differences in sexual behavior in the US are narrowing over time. Additionally, research is limited as to why these racial differences in normative sexual behavior may be present. It will be useful for future studies to expand analyses beyond simple group differences, and to test if additional covariates (e.g., cultural attitudes about sex and relationships) can account for any racial differences in these sexual behaviors.

For ethnicity, we also found that Hispanic respondents reported a higher frequency of oral, vaginal, and anal sex than non-Hispanic respondents, as well as slightly fewer lifetime vaginal sex partners and an earlier age of initiation of anal sex. To our knowledge, all prior studies explicitly examining ethnic differences in sexual behavior did so using the umbrella term “sexual intercourse” [1415]. We assessed sexual behavior in greater detail, specifying between oral, vaginal, and anal sex, expanding upon prior examinations of ethnic differences in sexual behavior. It will be important to replicate and dismantle such differences in future research.


While the online survey design provided for a highly efficient mode of data of collection for a national sample, several limitations should be noted. Although the Qualtrics XM platform ensures a sample that mirrors the US general population for the quota variables, all participating respondents had either internet or cell phone access. Though the large majority of the U.S. population does have internet access, there remains a small percentage who do not. Also, while Qualtrics guarantees specific quotas, it does not guarantee representation on other non-quota variables. Furthermore, due to time constraints, we focused on assessing oral, vaginal, and anal sex. Other surveys have asked about a wide range of sexual behaviors including solo behaviors, participation in group sex, use of sex toys, and various kink behaviors. While we did not include that breadth, we were able to delve into greater detail of oral, vaginal, and anal sex than some prior reports.

Additionally, multivariate logistic and linear regression models were used to explore the effects of Age, Age2, Sex, and their interactions on oral, vaginal, and anal sex. We did not, however, perform these analyses within demographic subgroups. While one-way ANOVAs were useful in testing for mean differences across subgroups, we did not test for interactions among age, sex, and the other demographic variables. Given we identified numerous group differences in sexual behavior, this will be an important goal for future research, though some subgroup analyses may require larger sample sizes than the SIPS to provide adequate power to detect differences (e.g., non-heterosexual orientation subgroups). There are also other demographic variables that we did not examine (e.g., income, education), as well as other behaviors (e.g., internet use, substance use) and psychological characteristics (e.g., personality) that are associated with sexual behavior, some of which we intend to examine in future reports. Subgroups could also be further dissected in large samples, e.g., sexual attraction as a distinct facet of sexual orientation [38]. There are other demographic variables that we did not examine (e.g., income, education), as well as other behaviors (e.g., internet use, pornography consumption, substance use) and psychological characteristics (e.g., personality) that may be associated with sexual behavior, some of which we intend to examine in future reports [3940].

Overall, the results are consistent with most prior findings regarding patterns of oral, vaginal, and anal sex in the United States, and help establish the representativeness of the SIPS sample. The evidence for its representativeness provides a basis on which future investigations can examine and make valid inferences regarding associations among sexual behavior, technology, and adjustment. Future reports will analyze additional correlates of sexual behavior, including social media and dating app use, substance use, mental health, personality, and interpersonal relationship traits to explore how modern technology usage impacts the expression of sexual and romantic behavior.

The agony of partner choice: Excessive partner availability increased fear of being single, and perceived overload, and decreased self-esteem

The agony of partner choice: The effect of excessive partner availability on fear of being single, self-esteem, and partner choice overload. Marina F. Thomas, Alice Binder, Jörg Matthes. Computers in Human Behavior, August 6 2021, 106977.


• Survey (Study 1) and experiment (Study 2) both showed adverse effects of excessive partner availability.

• In Study 1, dating app use related to increased partner availability, which in turn related to higher fear of being single.

• In Study 2, we manipulated low, moderate, or high partner availability by assigning 11, 31, or 91 dating app profiles.

• Higher partner availability increased fear of being single, and perceived overload, and decreased self-esteem.

Abstract: Dating apps advertise with high availability of potential partners because users seem to prefer extensive choice. However, on the basis of consumer decision making research, we theorized that such excessive choice could have adverse effects, specifically on fear of being single, self-esteem, and partner choice overload. In Study 1, a survey with 667 adults between 18 and 67, dating app use was associated with an increased perception that the number of potential partners is numerous which, in turn, predicted higher fear of being single. In Study 2, we replicated the positive effect of partner availability on fear of being single in an experimental design with 248 adults between 18 and 38. We experimentally induced low, moderate, or high partner availability by assigning 11, 31, or 91 dating app profiles of allegedly available potential partners to participants. High (compared to low) partner availability increased fear of being single, decreased participants’ state self-esteem, and increased partner choice overload. Findings demonstrate pitfalls of excessive swiping on dating apps and extend choice overload literature by revealing effects on novel outcomes.

Keywords: Dating app usePartner availabilityFear of being singleSelf-esteemPartner choice overload

Political Taste: Exploring how perception of bitter substances may reveal risk tolerance and political preferences

Friesen, A., Ksiazkiewicz, A., & Gothreau, C. (2021). Political Taste: Exploring how perception of bitter substances may reveal risk tolerance and political preferences. Politics and the Life Sciences, 1-47. doi:10.1017/pls.2021.20

Those who have a higher degree of preference for bitter tastes also tend to be more risk tolerant and to participate in politics.