Rolf Degen summarizing... Deepfakes are much less impactful than the scaremongering in the media might lead you to believe

You Won't Believe What They Just Said! The Effects of Political Deepfakes Embedded as Vox Populi on Social Media. Michael Hameleers, Toni G. L. A. van der Meer, Tom Dobber. Social Media + Society, August 25, 2022. https://doi.org/10.1177/20563051221116346

Abstract: Disinformation has been regarded as a key threat to democracy. Yet, we know little about the effects of different modalities of disinformation, or the impact of disinformation disseminated through (inauthentic) social media accounts of ordinary citizens. To test the effects of different forms of disinformation and their embedding, we conducted an experimental study in the Netherlands (N = 1,244). In this experiment, we investigated the effects of disinformation (contrasted to both similar and dissimilar authentic political speeches), the role of modality (textual manipulation versus a deepfake), and the disinformation’s embedding on social media (absent, endorsed or discredited by an (in)authentic citizen). Our main findings indicate that deepfakes are less credible than authentic news on the same topic. Deepfakes are not more persuasive than textual disinformation. Although we did find that disinformation has effects on the perceived credibility and source evaluations of people who tend to agree with the stance of the disinformation’s arguments, our findings suggest that the strong societal concerns on deepfakes’ destabilizing impact on democracy are not completely justified.

Keywords: deepfakes, disinformation, endorsement, misinformation

Discussion

Although previous research has experimentally tested the impact of political deepfakes (Dobber et al., 2020; Vaccari & Chadwick, 2020), important questions remain: Do deepfakes in the political realm have a persuasive advantage over textual modes of deception, and are its effects contingent upon the endorsement by (fake) social media accounts in a “participatory” disinformation order (Lukito et al., 2020; Starbird, 2019)? Our main findings indicate that disinformation was rated as substantially less credible than an unrelated authentic speech. However, disinformation was not rated as substantially less credible than malinformation based on an authentic speech of the depicted political actor. Finally, exposure to a deepfake did not yield stronger effects than exposure to textual disinformation.

These findings contradict the ubiquitous concerns on deepfakes in the current digital information age and are not in line with literature on the persuasiveness of multimodal framing (Powell et al., 2018) or deepfakes (Lee & Shin, 2021). To some extent, the lack of effects is in line with previous research on deepfakes indicating that deepfakes do not directly mislead news users (Dobber et al., 2020; Vaccari & Chadwick, 2020). Rather, deepfakes may have a more indirect effect by making recipients unsure on what or whom to believe, which, in turn, reduces people’s trust in (online) news (Vaccari & Chadwick, 2020).

Regarding the embedding of disinformation on social media, we found that discrediting the fabricated statements can make disinformation appear more credible. The social endorsement cue does not have this effect. However, endorsing a disinformation message on social media resulted in a more positive evaluation of the depicted politician compared to the absence of such an endorsement. This can be understood as an in-group serving bias: The presence of a source cue similar to the recipient may enhance credibility. These findings show that disinformation agents employing trolls or bots that use inauthentic social media profiles are only effective in increasing the message’s credibility when a fake message is discredited. The democratic implications of these findings are optimistic: Deepfakes, at least based on the current state-of-the-art, do not seem to be as dangerous for society as assumed (Paris & Donovan, 2020). While concerns about information pollution and eroding public trust remain, deepfakes’ ability to destabilize democracy should not be overstated.

We did find some support for the conditional effects of deepfakes and textual disinformation. Overall, disinformation is more effective in affecting the credibility ratings and positive evaluations of the depicted politician among news users already inclined to support the attitudinal stance of disinformation’s statements—which is in line with extant research on the indirect impact of disinformation campaigns (e.g., Schaewitz et al., 2020). We can understand this as a confirmation bias (e.g., Knobloch-Westerwick et al., 2017): Disinformation that is congruent with people’s prior beliefs may reinforce these existing beliefs. Yet, we did not find support for a moderating role of prior levels of issue agreement on disinformation’s impact on message congruent beliefs. We can explain this as a ceiling effect: People already inclined to support the attitudinal stance of disinformation are not further bolstering their beliefs based on one single message that reassures the attitudes they already hold.

Despite contributing to our understanding of the political consequences of exposure to socially endorsed deepfakes, this article has a number of limitations. As the deepfake was almost as credible as an authentic decontextualized video (malinformation), we believe that the lack of effects was not only due to technological failures of the deepfake itself but also the lack of plausibility of the extremist political statements associated with the more moderate political actor. Yet, we aimed to strike a balance between actually voiced statements by the political actor and a delegitimizing narrative that would harm the political actor by making him look bad. To achieve this, some deviation from the truth and familiar statements was needed. The finding that people do not clearly differentiate between fabricated disinformation and decontextualized malinformation is an important finding in its own right: In times when the truth has become more relative (e.g., Van Aelst et al., 2017), people may also distrust authentic information when it triggers suspicion due to its unusual nature.

This specific trade-off between audiovisual credibility and argumentative discrepancies needs to be teased out further in the future: How far can a deepfake deviate from a political actor’s profile to still be perceived as credible, and what persuasive techniques can be used to make inauthentic arguments seem real? Hence, future research may experiment with different conditions that are more or less plausible and more or less distant to the everyday communication of a known target. They may also more centrally take into account people’s existing knowledge and beliefs related to the depicted politician’s issue positions. If deepfakes are no longer credible when they deviate too much from reality, this may have positive implications for democracy: There are limits to the “fake reality” shown in synthetic videos, and deepfakes are not capable of making everyone say anything while remaining credible.

We should also note that the construct of perceived credibility we used may mean different things for different participants. While some may interpret the statements as referring to the authenticity of the presented materials, others may see it as the “truth value” of the statements themselves (Lewandowsky, 2021). Against this backdrop, some participants may find a deepfake uncredible because the statements do not have truth value, whereas others detect deception in the presentation of the video. Although robustness checks distinguishing between these drivers of credibility do not point to substantial differences, we suggest future research to rely on a more comprehensive multidimensional measure of credibility that distinguishes between these interpretations. In addition, although exposure to one short deepfake on its own may not affect polarization or political evaluations, the cumulative (targeted or algorithmic) exposure to attitude-consistent disinformation may, over time, exert a stronger influence on people’s beliefs and behaviors. Finally, future research may also need to take individual-level differences into account that could predict susceptibility and resilience to disinformation, such as people’s trust in social versus mainstream media, and formats more likely to contain disinformation.

As a key take-away point, we stress that although the disrupting impact of deepfakes on democracy should not be overstated, deepfakes’ ability to become part of native online political discussions may offer a persuasive advantage when it can find nuanced ways to delegitimize political actors or amplify the political beliefs of targeted groups in society via social media.

We review the evidence linking gender to dishonesty and conclude that men are often more dishonest than women, especially in competitive settings where lies advance self-interest

Gender Similarities and Differences in Dishonesty. Jessica A. Kennedy, Laura J. Kray. Current Opinion in Psychology, August 24 2022, 101461. https://doi.org/10.1016/j.copsyc.2022.101461

Abstract: We review the evidence linking gender to dishonesty and conclude that men are often more dishonest than women, especially in competitive settings where lies advance self-interest. However, gender differences in dishonesty are often small and mutable across situations. We propose that attending to self-regulatory constructs such as moral identity might help researchers move beyond the evolutionary-cultural debates over the origin of gender differences toward identifying factors that promote honesty from both genders.

Keywords: Gender differencesSex differencesDishonestyHonestyTruthMoralityEthics

We experimentally manipulated the reported age of unfamiliar technology and found that people evaluate it more favorably when it is described as originating before (vs. after) their birth

The Golden Age Is Behind Us: How the Status Quo Impacts the Evaluation of Technology. Adam H. Smiley, Matthew Fisher. Psychological Science, August 24, 2022. https://doi.org/10.1177/09567976221102868

Abstract: New technology invariably provokes concerns over potential societal impacts. Even as risks often fail to materialize, the fear continues. The current research explored the psychological underpinnings of this pattern. Across four studies (N = 2,454 adults recruited via Amazon Mechanical Turk), we found evidence for the role of status quo thinking in evaluating technology. In Study 1, we experimentally manipulated the reported age of unfamiliar technology and found that people evaluate it more favorably when it is described as originating before (vs. after) their birth. In Studies 2 through 4, participants’ age at the time of invention strongly predicts attitudes toward a wide range of real-world technologies. Finally, we found that individual differences in status-quo-based decision-making moderated evaluations of technology. These studies provide insight into how people respond to the rapidly changing technological landscape.

Keywords: psychology of technology, status quo, judgment, open data, open materials, preregistered

Contrary to findings from previous correlational studies, we do not find any significant impact of social media usage as it was defined in our study on well-being and academic success

Effects of restricting social media usage on wellbeing and performance: A randomized control trial among students. Avinash Collis, Felix Eggers. PLoS, August 24, 2022. https://doi.org/10.1371/journal.pone.0272416

Abstract: Recent research has shown that social media services create large consumer surplus. Despite their positive impact on economic welfare, concerns are raised about the negative association between social media usage and well-being or performance. However, causal empirical evidence is still scarce. To address this research gap, we conduct a randomized controlled trial among students in which we track participants’ daily digital activities over the course of three quarters of an academic year. In the experiment, we randomly allocate half of the sample to a treatment condition in which social media usage (Facebook, Instagram, and Snapchat) is restricted to a maximum of 10 minutes per day. We find that participants in the treatment group substitute social media for instant messaging and do not decrease their total time spent on digital devices. Contrary to findings from previous correlational studies, we do not find any significant impact of social media usage as it was defined in our study on well-being and academic success. Our results also suggest that antitrust authorities should consider instant messaging and social media services as direct competitors before approving acquisitions.

Discussion

In this paper, we analyzed the effects of restricting social media usage. We did not find significant causal effects of social media usage on well-being or academic performance, other than students attempting (but not succeeding) to pass more courses or courses with more credits. However, we found robust evidence of substitution effects that can potentially explain the null finding. Specifically, we showed that social media and instant messaging apps can be substitutes. The European Commission approved Facebook’s acquisition of WhatsApp in 2014 based on Facebook’s claim that it operates in a different market and does not compete directly with WhatsApp [52]. Our results indicate that they are in fact direct competitors. After acquiring WhatsApp, Facebook started automatically matching its users’ profiles with their WhatsApp accounts and has started integrating WhatsApp, Instagram and Facebook user accounts [53]. The European Commission fined Facebook €110 million in 2017 for this practice because Facebook had provided misleading information about the feasibility of automatically matching profiles during its acquisition of WhatsApp. However while announcing this fine, the Commission still maintained its belief that Facebook and WhatsApp do not directly compete with each other [54]. Antitrust authorities should consider the market power of this combined entity if the world’s biggest social media platforms are integrated with the world’s biggest instant messaging platform. This finding also raises the question how to properly define social networks, for future academic studies or antitrust cases.

While we found null results estimating the causal impact of social media usage on well-being and academic performance, and not all null results matter, we believe that null results are interesting and important in this context. The media has hyped correlational studies showing a negative association between social media usage and well-being and it is important to balance this narrative through causal evidence. A limitation of our study is the lack of a larger sample size to detect smaller effects. While these small effects might not be economically significant, more research is needed using massive samples. Future research can also look at differences between Android and iOS users in more detail with larger samples since we lack power to analyze these differences in our current study. However, it is challenging to recruit a large number of subjects from a representative sample for a long-term study. Direct collaborations with social media platforms or internet service providers (which control internet traffic) could be a way of obtaining data from larger samples. These would also facilitate more targeted interventions such as restricting only content consumption or social interactions on social media [18].

It is interesting to notice that while social media generates large amount of consumer surplus [3], it doesn’t seem to affect the subjective well-being of users. Future research can explore this wedge between consumer surplus and subjective well-being and see whether they are correlated for some products and uncorrelated for others. Future research should also explore the addictiveness of social media in more detail [55]. Our findings in block 3 show that the students in the treatment condition go back to their old habits and do not adopt a lower social media usage that they experienced in block 2. On the other hand, showing students how much time they are spending on social networks via the software seems to have an overall negative trend on its usage (comparing usage in block 1 and block 3). Curing social media addiction (if it is indeed addiction) might therefore be a longer process. Future research can look at mechanisms for the emergence of social media addiction, for e.g. through targeted advertising or news feed algorithms and features of social media apps (e.g. video sharing) which are correlated with addiction.

Moreover, due to our student sample implications for the general population are limited. It could be that students use social media mostly for communication purposes and therefore show significant substitution effects with instant messaging. We might see different effects for users who visit social media for content consumption, e.g., watching videos, instead of social interaction [18]. In this regard, newer social media services such as TikTok might have a different effect. However, these and other comparable social media services were not relevant at the time we conducted the study (as we measured in block 1). More research is needed looking at emerging social media platforms such as TikTok. Moreover, one could define social media more broadly to include instant messaging services and implement a stricter restriction involving all types of communication and social networking apps. However, conducting such a study for any length of time is a challenging endeavor.

Additionally, while we study the impact of social media on students and academic performance, future research can look at workplace settings and study the impact of social media and its substitutes on worker productivity and well-being. We believe that rigorous causal evidence through randomized controlled trials and objectively measured time spent is the way forward in addressing questions regarding the impact of technology on well-being.

The widespread adoption of most major technologies in the past such as radio, television, video games and computers was followed with unfounded fears about their impact on well-being. This story repeats again with social media. We find that social media usage does not cause lower well-being or poor academic performance. Rather, we demonstrate that students find other means of social networking using instant messaging when exogenously restricting their social media usage. To conclude: You can take social networking away from the students, but you cannot take students away from their social network.

No Evidence That Siblings’ Gender Affects Personality Across Nine Countries

No Evidence That Siblings’ Gender Affects Personality Across Nine Countries. Thomas Dudek et al. Psychological Science, August 23, 2022. https://doi.org/10.1177/09567976221094630

Abstract: Does growing up with a sister rather than a brother affect personality? In this article, we provide a comprehensive analysis of the effects of siblings’ gender on adults’ personality, using data from 85,887 people from 12 large representative surveys covering nine countries (United States, United Kingdom, The Netherlands, Germany, Switzerland, Australia, Mexico, China, and Indonesia). We investigated the personality traits of risk tolerance, trust, patience, locus of control, and the Big Five. We found no meaningful causal effects of the gender of the next younger sibling and no associations with the gender of the next older sibling. Given the high statistical power and consistent results in the overall sample and relevant subsamples, our results suggest that siblings’ gender does not systematically affect personality.

Keywords: personality, siblings, gender, open materials

Discussion

Overall, we conclude that siblings’ gender does not meaningfully affect personality. Although data came from only nine countries (with a predominance on Western countries), the consistently small associations challenge the notion that any type of universal, gendered sibship dynamics affects personality. This conclusion also aligns with recent findings suggesting that one’s ordinal position among siblings does not meaningfully affect personality (Botzet et al., 2021; Damian & Roberts, 2015b; Lejarraga et al., 2019; Rohrer et al., 2015, 2017). Of course, it is possible that the effects of siblings’ gender and birth-order position are even more subtle and thus not detectable even when very large samples are investigated. This interpretation would align with recent suggestions that environmental influences, just like genetic influences, may be driven by thousands of factors, each with very small effect sizes (von Stumm & d’Apice, 2022). However, taking findings from behavioral genetics into account, it seems like these environmental causes are more likely to be found outside of the family environment (Briley & Tucker-Drob, 2014; Vukasović & Bratko, 2015).

It is also possible that the proposed mechanisms of both social-learning and sibling-differentiation theory apply in varying degrees in different families, resulting in average effects that net out at zero but that may occasionally “show up” in individual studies as significant effects. However, this account does not provide the most parsimonious explanation for discrepancies between our study and the past literature on the topic. Given inconsistent methodologies and small sample sizes, it seems reasonable that at least some of the incoherence can be attributed to publication bias (Ioannidis, 2005), which can result in a “continuous stream of conflicting results” (Damian & Roberts, 2015a). Furthermore, both social learning and sibling differentiation suggest that the effects of siblings’ gender are mediated through siblings’ personality—but the link between gender and personality is only of medium strength in the first place, even when an index designed to maximize differences is used. Thus, large effects of sibling gender may be implausible to begin with.

Lastly, sibling gender may not affect the widely used broad personality measures that we investigated, but recent economic research suggests that it does affect important life outcomes. Findings suggest that brothers decrease women’s labor earnings and that this may be partly driven by increased traditional family attitudes (Brenøe, 2022; Cools & Patacchini, 2019; Rao & Chatterjee, 2018). Investigating the specific mechanisms behind this brother-earnings penalty—whether they are psychological, sociological, or economic in nature—seems a worthwhile research endeavor. Our findings suggest that personality differences do not play a major part in this story.

Sniffing of Body Odors and Individual Significance of Olfaction Are Associated with Sexual Desire: A Cross-Cultural Study in China, India, and the USA

Sniffing of Body Odors and Individual Significance of Olfaction Are Associated with Sexual Desire: A Cross-Cultural Study in China, India, and the USA. Zi-lin Li, Thomas Hummel & Lai-quan Zou. Archives of Sexual Behavior, Aug 23 2022. https://rd.springer.com/article/10.1007/s10508-022-02398-1

Abstract: Olfactory sensations contribute to sexual desire and sexual behavior. However, the degree to which individual importance of olfactory function and body odors relate to sexual desire is not known. This study was conducted to preliminarily examine these relationships among Chinese college students (N = 1903) via the Importance of Olfaction Questionnaire, the Body Odor Sniffing Questionnaire, and the Sexual Desire Inventory, which were used to measure subjective significance of olfaction, frequency of sniffing self or others, and sexual desire, respectively. Individuals who assigned higher importance to olfaction or engaged more in body odor sniffing showed stronger sexual desire. We further explored these associations in different cultures to determine whether cultural consistency existed. We conducted a second study to make cross-cultural comparisons between Indian (N = 313) and US (N = 249) populations. For both countries, a higher importance placed on olfaction and a higher prevalence of body odor sniffing were consistently associated with stronger sexual desire. In conclusion, our study confirmed that people who placed more value on olfactory function or engaged more in body odor sniffing showed stronger sexual desire. These correlations were consistent for both sexes and across different cultures, further indicating the importance of olfaction in sexuality.

A Meta-analysis of the Effects of Trigger Warnings, Content Warnings, and Content Notes: No effect on affective responses to negative material nor on educational outcomes

Bridgland, Victoria, Payton J. Jones, and Benjamin W. Bellet. 2022. “A Meta-analysis of the Effects of Trigger Warnings, Content Warnings, and Content Notes.” OSF Preprints. August 23. doi:10.31219/osf.io/qav9m

Abstract: Trigger warnings, content warnings, or content notes are alerts about upcoming content that may contain themes related to past negative experiences. Advocates claim that warnings help people to emotionally prepare for or completely avoid distressing material. Critics argue that warnings both contribute to a culture of avoidance at odds with evidence-based treatment practices and instill fear about upcoming content. Recently, a body of psychological research has begun to investigate these claims empirically. We present the results of a meta-analysis of all empirical studies on the effects of these warnings. Overall, we found that warnings have no effect on affective responses to negative material nor on educational outcomes (i.e., comprehension). However, warnings reliably increase anticipatory affect. Findings on avoidance were mixed, suggesting either that warnings have no effect on engagement with material, or that they increase engagement with negative material under specific circumstances. Limitations and implications for policy and therapeutic practice are discussed.

Abstinence from alcohol appears to be associated with an increased risk for all-cause dementia

The relationship between alcohol use and dementia in adults aged over 60 years: A combined analysis of prospective, individual-participant data from 15 international studies. Louise Mewton et al. Addiction, August 22 2022. https://doi.org/10.1111/add.16035

Abstract

Aim: To synthesise international findings on the alcohol-dementia relationship, including representation from low- and middle-income countries.

Methods: Individual participant data meta-analysis of 15 prospective epidemiological cohort studies from countries situated in six continents. Cox regression investigated the dementia risk associated with alcohol use in older adults aged over 60 years. Additional analyses assessed the alcohol-dementia relationship in the sample stratified by sex and by continent. Participants included 24,478 community dwelling individuals without a history of dementia at baseline and at least one follow-up dementia assessment. The main outcome measure was all-cause dementia as determined by clinical interview.

Results: At baseline, the mean age across studies was 71.8 (standard deviation 7.5, range 60-102 years), 14,260 (58.3%) were female, and 13,269 (54.2%) were current drinkers. During 151,636 person-years of follow-up, there were 2,124 incident cases of dementia (14.0 per 1,000 person-years). When compared with abstainers, the risk for dementia was lower in occasional (hazard ratio [HR]: 0.78; 95% confidence interval [CI]: 0.68-0.89), light-moderate (HR: 0.78; 95% CI: 0.70-0.87) and moderate-heavy drinkers (HR: 0.62; 95% CI: 0.51-0.77). There was no evidence of differences between lifetime abstainers and former drinkers in terms of dementia risk (HR: 0.98; 95% CI: 0.81-1.18). In dose-response analyses, moderate drinking up to 40g/day was associated with a lower risk of dementia when compared with lifetime abstaining. Among current drinkers, there was no consistent evidence for differences in terms of dementia risk. Results were similar when the sample was stratified by sex. When analysed at the continent level, there was considerable heterogeneity in the alcohol-dementia relationship.

Conclusions: Abstinence from alcohol appears to be associated with an increased risk for all-cause dementia. Among current drinkers, there appears to be no consistent evidence to suggest that the amount of alcohol consumed in later life is associated with dementia risk.

On average, refugees assimilate both culturally and economically; however, while refugees assigned to more hostile regions converge to local culture more quickly, they do not exhibit faster economic assimilation

Scared Straight? Threat and Assimilation of Refugees in Germany. Philipp Jaschke, Sulin Sardoschau & Marco Tabellini. NBER Working Paper 30381. Aug 2022. DOI 10.3386/w30381

Abstract: This paper studies the effects of threat on convergence to local culture and economic assimilation of refugees, exploiting plausibly exogenous variation in their allocation across German regions between 2013 and 2016. We combine novel survey data on cultural preferences and economic outcomes of refugees with corresponding information on locals, and construct a threat index that integrates contemporaneous and historical variables. On average, refugees assimilate both culturally and economically. However, while refugees assigned to more hostile regions converge to local culture more quickly, they do not exhibit faster economic assimilation. Our evidence suggests that refugees exert more assimilation effort in response to local threat, but do not integrate faster because of higher discrimination in more hostile regions.

Failed replication: The “brain drain” effect of Ward et al. (2017), the purported effect on cognitive performance due to the mere presence of one's smartphone

Reexamining the “brain drain” effect: A replication of Ward et al. (2017). Ana C.Ruiz Pardo, John Paul Minda. Acta Psychologica, Volume 230, October 2022, 103717. https://doi.org/10.1016/j.actpsy.2022.103717

Abstract: The present study was a pre-registered direct replication of Ward et al.'s (2017) second experiment (OSF pre-registration found at: https://osf.io/5fq4r). This replication assigned both smartphone location (on desk, in pocket/bag, or outside of the testing room) and smartphone power (on, or off) for a total of six conditions. Participants completed an automated operation span (OSpan) task, a Cue-Dependent Go/No-Go task, and the smartphone attachment and dependency inventory. It was hypothesized that performance on an attention-demanding task (i.e., the OSpan task) would be worse for those in closer proximity to their smartphone (on desk) and that those with greater smartphone attachment and dependency would have a larger “brain drain” effect. Using the same tasks and conditions as in Ward et al.'s (2017) second experiment, the present study found that the “brain drain” effect did not replicate: there was no difference between smartphone location conditions on performance on either the o-span task or the go/no-go task. These findings demonstrate that the mere presence of one's smartphone may not be enough to affect cognitive performance. Understanding these effects is crucial in a time where smartphones are a basic necessity.

Keywords: Smartphone presenceAttentionResponse inhibitionSmartphone dependency

4. Discussion

Smartphones provide an easy and effective method of communicating with the world right at our fingertips. The rising prevalence of smartphones (Pew Research Center, 2019) has prompted research including possible behavioural addictions (WHO, 2015) and how these might affect cognitive abilities. Although there are many benefits to using a smartphone in terms of communication, the present study investigated how smartphones affect performance on cognitively demanding tasks. This was done by reexamining the “brain drain” effect (i.e., those who were in closer proximity to their smartphone performed worse on a cognitively demanding task, which is moderated by smartphone reliance) found by Ward et al.'s (2017) second experiment. The three main hypotheses (i.e., location effect, power effect, and moderation effect) from Ward et al. (2017) were evaluated in the present study.

4.1. The OSpan Task and the Cue-Dependent Go/No-Go task

There were no significant main or interaction effects of smartphone location on performance on OSpan absolute score. There was a significant main effect of cue type and an interaction effect of cue type and smartphone location on omission errors in the Cue-Dependent Go/No-Go task (Bezdjian et al., 2009). However, this effect was explored with tests of simple main effects and found no significant effect of smartphone location for either cue type. Overall, the present study did replicate Ward et al.'s null effect on the Cue-Dependent Go/No-Go task performance. More notably, however, the present study's findings failed to replicate Ward et al.'s main effect concerning performance on the OSpan task (Unsworth et al., 2005). Therefore, the “brain drain” effect was not replicated in the present study. The smartphone power effect hypothesis was supported: there was no significant difference between power conditions (i.e., powered ON vs. OFF) on performance for both tasks. This was a replication of Ward et al.'s findings.

4.2. Factor analysis of the smartphone attachment and dependency inventory

Findings from a principal components analysis on the smartphone attachment and dependency inventory (Ward et al., 2017) partially supported the two-factor findings from Ward et al. (i.e., smartphone dependence and emotional attachment), but also added a third factor: smartphone distractibility.

4.3. Moderation analysis on OSpan Score

Finally, the moderation effect did not replicate: smartphone dependency, emotional attachment, and distractibility were not significant moderators of OSpan performance. In contrast with Ward and colleagues, emotional attachment showed a trend for those in the desk condition, where higher emotional attachment predicted lower OSpan performance. It should be noted that this analysis was completed as a pre-registered analysis and was exploratory in nature. Overall, the present study demonstrated that the “brain drain” effect may not be a replicable effect of smartphone presence on cognition. Possible reasons for this are given.

4.4. Failure to replicate the “brain drain” effect

A stark difference in performance was observed between the present study's OSpan performance and in Ward et al.'s (2017) second experiment. This was one of the critical results in Ward et al., because they described the OSpan as a difficult working memory task intended to be sensitive to a decrease in cognitive capacity. They argued that this difficulty difference was the reason why they found an effect on OSpan performance but not on the Cue-Dependent Go/No-Go (Bezdjian et al., 2009) performance, and indeed this was the locus of the “brain drain” effect. However, participants in our study did not find the OSpan as challenging and the presence of their own smartphone on the desk did not seem to interfere with their performance on the task. Not only was the mean-difference in OSpan performance for the present study much smaller than for Ward et al. but also, the average performance between the present study and Ward et al. implies that participants in the present study did not find the OSpan task as challenging as in Ward et al.'s study. This difference was also seen when compared to Ward et al.'s first experiment, where average OSpan performance was lower than a score of 34. These differences may explain why participants in our experiment did not experience a “brain drain” in their performance: the task did not diminish participant’s available cognitive capacity. In fact, the present study showed participants with perfect performance on both the math and letter recall components and, consequently, there was a possible ceiling effect. This defeated the purpose of the OSpan as a more difficult cognitive task. Therefore, to determine the underlying mechanisms behind smartphones' impact on cognition, future work should use reliable and normed cognitive tasks. The Cambridge Brain Sciences (CBS; Hampshire et al., 2012) test battery, for example, evaluates a broad range of cognitive abilities such as selective attention, response inhibition, reasoning, and working memory. These short cognitive tests have been used across different populations (Wild et al., 2018) to test people across three main components (i.e., short-term memory, reasoning, and verbal ability) with varying difficulty levels. Therefore, using this test battery could examine how smartphone presence affects an overview of cognitive aspects and could explain why the present study did not replicate the “brain drain” effect.

Another limitation to consider in the present study was the measure for smartphone reliance. In order to directly compare the present study to Ward et al.'s second experiment, the smartphone attachment and dependency inventory (Ward et al., 2017) was used to measure participant’s smartphone attachment and dependency (i.e., reliance). However, current research typically uses additional measures to measure things such as nomophobia (i.e., the fear of being without one's phone or the internet; (Yildirim & Correia, 2015) and smartphone involvement (Walsh et al., 2010). Although the use of the smartphone attachment and dependency inventory (Ward et al., 2017) allowed the present study to directly compare findings to Ward et al.'s second experiment, measuring smartphone reliance based on only one scale limited the present study. Therefore, future research should expand on other measures of smartphone reliance.

Additionally, it should be noted that the present study focused on a North American population to compare directly to Ward et al.'s original study. However, as smartphone prevalence emerges globally and differently across countries (Silver, 2019), future research should consider comparing different countries' smartphone use.

In a large Dutch twin sample, we found that genetic variance accounted for 74% and 77% of whether people were pescatarian or vegetarian, respectively; the remaining variance was accounted for by non-shared environmental influences

The heritability of pescetarianism and vegetarianism. Laura W. Wesseldijk et al. Food Quality and Preference, August 23 2022, 104705. https://doi.org/10.1016/j.foodqual.2022.104705

Highlights

• Pescetarianism is 74% heritable and vegetarianism 77%.

• Genetic influences account for 70-80% of individual differences in abstinence from eating beef, pork, poultry, fish and shellfish.

• Individuals did not eat pork mostly because of health reasons, poultry, fish and shellfish because of dislike, and beef because of beliefs.

• Regardless of the different reasons for abstinence, heritability estimates were of a similar large magnitude.

Abstract: Genetic factors have a substantial influence on individuals' food preferences, but less is known about their influence on abstinence from eating meat and fish. Here we looked at the influence genetics may have on pescetarianism (not eating meat but eating fish) and vegetarianism (not eating meat and fish) in a Dutch twin sample (N = 8,196). We also examined genetic and environmental influences on abstinence from eating beef, pork, poultry, fish or shellfish separately and explored the reasons individuals gave for not eating these types of meat and fish (e.g., disliking, health concerns or beliefs). Abstinence from eating various meats or (shell)fish varied from 5.3% for beef to 46% for shellfish, and 3.7% did not eat meat (1.9% was pescatarian and 1.8% vegetarian). The prevalence of all abstinences was higher in women than men. Genetic factors accounted for 74% and 77% of variation in pescetarianism and vegetarianism, respectively, with the remaining variance accounted for by non-shared environmental influences. Heritability for abstinence from eating beef, pork, poultry, fish or shellfish ranged from 70 to 80%. Abstention from pork was mostly due to health concerns, abstention from poultry, fish and shellfish because of dislike, and abstention from beef because of beliefs (i.e., religion or convictions). Most pescatarians and vegetarians reported beliefs as one of their reason for abstinence (∼75%). Overall, regardless of the fact that different reasons seem to play a role in pescetarianism, vegetarianism and abstinence from eating different meats and fish, genetic factors undergirded all with a similar large magnitude.

 

See also Where the Rubber Meats the Road: Relationships between Vegetarianism and Socio-political Attitudes and Voting Behavior. John B. Nezlek & Catherine A. Forestell. Jul 15 2019. Ecology of Food and Nutrition, Volume 58, 2019 - Issue 6, pp 548.559. https://www.bipartisanalliance.com/2020/01/possible-genetic-predisposition-to.html

4. Discussion

In a large Dutch twin sample, we found that genetic variance accounted for 74% and 77% of whether people were pescatarian or vegetarian, respectively. The remaining variance was accounted for by non-shared environmental influences. Hence, we detected no effect of the common environment, which should include social transmission from parents and other forms of environmental exposures shared by twins. These results are in line with findings from the recent Finnish study that found vegetarianism/veganism to be 76% heritable (Çınar et al., 2021). We replicated the heritability estimate in a sample of a similar age (Finnish sample M = 29.51 years, SD = 7.84, Dutch sample M = 35.25 years, SD = 15.26), though with a much lower prevalence of vegetarianism. This is, however, roughly in line with country-specific prevalence for vegetarianism (approximately 4-5% in the Netherlands and 11% in Finland) (Motrøen, 2020, van Rossum et al., 2020). Furthermore, we found the degree of genetic influences on abstaining from beef, pork, poultry, fish and shellfish to all be roughly around 70 to 80%. Notably, common environment factors were strongest for abstention from pork (28%), though the influence was non-significant with an alpha of .01 (corrected for multiple testing). In a previous study, the heritability of food preference was explored in the same sample (Vink et al., 2020). The broad sense heritability for liking of meat and fish, measured on a continuous scale, varied between 41% and 60%. This suggests that genetic factors play a larger role in abstinence from eating meat and fish than in the liking of these foods.

Pork was the only type of meat that individuals in our sample abstained from mostly because of health concerns. Beliefs, which was often selected as a reason not to eat particular types of meat (especially for beef and not eating meat), could reflect religion or conviction (in the survey the example given was veganism). We recommend future studies to differentiate the reason ‘beliefs’ and ask in more depth about the specific beliefs or convictions, like type of religion, mitigation, climate change or animal welfare. No information on religion was obtained in the current study. However, information obtained for 79.2% of the sample from one or more other surveys showed that 22% of the sample reported having no religious affiliation, 77.5% reported a religious affiliation at one point in their lives and 0.5% indicated some belief but no affiliation with a specific religion. The vast majority of those ever affiliated with a religion indicated to be Christian or to be raised as Christian and only a small minority indicated affiliations with religions that forbid the consumption of pork, beef, or both. It is therefore unlikely that beliefs reflect the influence of religion. Interestingly, people mostly abstained from poultry, fish and shellfish due to dislike. Some individuals reported 'other reasons' for their abstinence from eating meat or fish. We can only speculate about what those other reasons could be. Given that concerns about animal welfare and environmental sustainability were not among the response options, these 'other reasons' could have reflected such concerns. Additionally, some people might not eat certain types of meat or fish because they are too expensive (like shellfish), although the prevalence of being pescatarian and vegetarian was higher among higher educated participants (with probably higher incomes) than moderate or lower educated participants. Overall, regardless of the fact that different reasons seem to motivate abstention from beef, poultry, pork, fish or shellfish, genetic factors undergirded abstinence from eating all types of meat and fish with a similar magnitude (around 70-80%).

This study has limitations. We made use of self-reports. Whereas participants in the earlier Finnish sample answered yes or no to being vegetarian or vegan (Çınar et al., 2021), participants in the current study were designated as pescatarian or vegetarian based on reporting abstaining from eating specific types of meat and fish. It is possible that, in the Finnish sample, being vegetarian was interpreted as abstaining from eating meat, but not fish, or as abstaining only from certain types of meat. Conversely, some participants in the current study could abstain from beef, pork or poultry, but eat a different type of meat. Further, standard assumptions of classical twin modeling apply here (Verweij, Mosing, Zietsch, & Medland, 2012). Inferences are limited to the population which was approached for the study. The factors underlying vegetarianism in other populations might be different, especially for populations from different cultures, with different religions and/or a higher prevalence of vegetarianism. Lastly, we were initially also interested in investigating environmental and genetic influences on abstaining from all types of meats, fish and dairy (i.e., being vegan). However, our sample included only 20 vegans. Similarly, the majority of pescatarians and vegetarians were female and the data therefore did not allow to investigate sex differences in the genetic architecture. Larger sample sizes are needed to examine genetic influences on veganism, differences between males and females in the heritability of food abstinence, and genetic correlations between abstinence from different types of food. Genetic correlations (with either twin studies or molecular genetic approaches) between vegetarianism and other variables (e.g., education or personality traits) could shed light on the mechanisms underlying dietary choices. We would expect that abstaining for reasons like beliefs with respect to sustainability and animal welfare are more related to genetic factors for personality, while abstaining for reasons like dislike or allergy are more related to genetic factors for more biological processes (for example, genes that code for taste receptors). For this second scenario, we expect that molecular genetic studies will identify genetic variants that shed more light on the underlying biological mechanisms (e.g., genes related to taste, as has been found for coriander abstinence (Eriksson et al., 2012), versus genes related to personality).

To conclude, we confirmed that genetic factors play a large role in individual's choice to be pescatarian, vegetarian or to not eat meat (74-80%) in a Dutch population. Genetic influences on abstaining from beef, pork, poultry, fish and shellfish ranged from 70 to 80%, regardless of the fact that different reasons seem to motivate abstinence from these different types of food. Future research should further investigate genetic correlations and genetic influences on associations between vegetarianism and other psychological traits. 

Once amongst the tallest people in the world, the generations of bison-reliant people born after the slaughter lost their entire height advantage

The Slaughter of the Bison and Reversal of Fortunes on the Great Plains. Donn. L. Feir, Rob Gillezeau & Maggie E.C. Jones. NBER Working Paper 30368, August 2022. DOI 10.3386/w30368

Abstract: In the late nineteenth century, the North American bison was brought to the brink of extinction in just over a decade. We demonstrate that the loss of the bison had immediate, negative consequences for the Native Americans who relied on them and ultimately resulted in a permanent reversal of fortunes. Once amongst the tallest people in the world, the generations of bison-reliant people born after the slaughter lost their entire height advantage. By the early twentieth century, child mortality was 16 percentage points higher and the probability of reporting an occupation 29.7 percentage points lower in bison nations compared to nations that were never reliant on the bison. Throughout the latter half of the twentieth century and into the present, income per capita has remained 28 percent lower, on average, for bison nations. This persistent gap cannot be explained by differences in agricultural productivity, self-governance, or application of the Dawes Act. We provide evidence that this historical shock altered the dynamic path of development for formerly bison-reliant nations. We demonstrate that limited access to credit constrained the ability of bison nations to adjust through respecialization and migration.

VII. Conclusion

At the beginning of the nineteenth century, the North American bison roamed the Great Plains in the tens of millions, but by 1880, the bison were nearly extinct, the result of a mass slaughter that occurred within as little as 10 years. This is the first paper to empirically quantify the persistent effects of the slaughter on the Native American nations who relied on the bison for over 10,000 years prior to its extinction. We compile historical, anthropological, geographic, and modern economic data to show that the elimination of the bison affected the well-being of the Indigenous peoples who relied on them, both immediately after the bison’s decline, and up to 150 years later. We argue that the loss of the bison resulted in a reversal of fortunes: historically, bison-reliant societies were among the most well-off people on the continent, but today, they are among the poorest.

We study the dynamic path of development through which this shock has persisted into the present day and demonstrate that early access to credit could have mitigated the persistent effects of the loss of the bison. While the loss of the bison was a unique historical event, large regional economic shocks are not. Similarly, Native Americans occupy a unique institutional space in the United States but barriers to adjustment, like costly migration, low levels of development, and credit constraints are common. The experiences of the formerly bison-reliant peoples, important in their own right, also shed light on how economic shocks can persist for decades in the absence of access to other financial resources.

Women were seven times more likely to lose work during the nationwide lockdown, and conditional on losing work, eleven times more likely to not return to work subsequently, compared to men; and on and on

Down and out? The gendered impact of the Covid-19 pandemic on India’s labour market. Rosa Abraham, Amit Basole & Surbhi Kesar. Economia Politica volume 39, pages 101–128. Jul 14 2022. https://link.springer.com/article/10.1007/s40888-021-00234-8

Abstract: The Covid-19 pandemic has created unprecedented disruptions in labour markets across the world including loss of employment and decline in incomes. Using panel data from India, we investigate the differential impact of the shock on labour market outcomes for male and female workers. We find that, conditional on being in the workforce prior to the pandemic, women were seven times more likely to lose work during the nationwide lockdown, and conditional on losing work, eleven times more likely to not return to work subsequently, compared to men. Using logit regressions on a sample stratified by gender, we find that daily wage and young workers, whether men or women, were more likely to face job loss. Education shielded male workers from job loss, whereas highly educated female workers were more vulnerable to job loss. Marriage had contrasting effects for men and women, with married women less likely to return to work and married men more likely to return to work. Religion and gender intersect to exacerbate the disproportionate impact, with Muslim women more likely to not return to work, unlike Muslim men for whom we find religion having no significant impact. Finally, for those workers who did return to work, we find that a large share of men in the workforce moved to self-employment or daily wage work, in agriculture, trade or construction. For women, on the other hand, there is limited movement into alternate employment arrangements or industries. This suggests that typical ‘fallback’ options for employment do not exist for women. During such a shock, women are forced to exit the workforce whereas men negotiate across industries and employment arrangements.

Discussion and conclusion

The stringent economic lockdown in India affected workers across regions, industries, and employment arrangements. However, the impact has been quite gendered in its nature. Women, in particular, have been more adversely affected relative to men in terms of their labour market participation. Our findings suggest that during the lockdown, women were far more likely to lose work compared to men. Moreover, even after the lifting of the lockdown and with easing of mobility and other restrictions, women’s recovery into employment has been substantially lower compared to men. While men experienced an almost-complete recovery into employment, a significant proportion of women experienced job loss of a more permanent nature. In an economy where women’s work participation rates have been historically low and declining (Mehrotra & Parida, 2017), this adverse impact and muted recovery of women’s workforce participation is particularly worrying.

Possible reasons for this gender disparity can be attributed both to the supply side as well as the demand-side factors. On the supply side, increased burden of household work, lack of socially or market-provided childcare options and shutdown of schools could force women to stay at home, as well as spend more time in care and other unpaid activities, as compared to men. Consistent with this, Deshpande (2020) confirms muted employment recovery for women with young children. While our regression estimates do not find a significant impact on the presence of children, we find that that women from larger households (and hence having more domestic work) were less likely to return to work.

On the demand side, it has been argued that the disproportionately higher impact on women can be explained on the basis of women having a higher employment in those sectors most affected by the pandemic, such as health and education, and being employed in more tenuous employment contracts (World Bank, 2020a). This occupational and industrial segregation exposes women far more than men to the economic impacts of the pandemic (Oxfam, 2021). However, the results from our regression estimates show that the disproportionate impact on women remains even after controlling for industry and employment arrangements. Women, irrespective of the nature or industry of work, are more vulnerable to lose work and not return to work.

It is likely that other supply side factors that are not captured in our estimates explain the higher impact on and muted recovery of women in the workforce. In the face of an overall decline in labour demand, gender norms that ensure that scarce economic opportunities flow to men in preference to women, could constrain women’s (re-)entry into the labour market. Such gender norms may also explain the relative lack of fallback options for women within the workforce, forcing them to move out entirely. In the face of such a shock, while men negotiate labour market spaces by moving across sectors and industries, women are often left with little or no choice and are forced to exit.

Further, continued restrictions on mobility and limited functioning of public transport facilities also differentially impact women more since they are relatively more dependent on public transport (Shah et al., 2017). For many women workers, increased police patrolling for enforcing social isolation rules have also exposed them to more instances of harassment and aggression, further affecting their return to work (ISST, 2020).

Taken together, our results point to large movements downwards and outwards, particularly for women workers. We believe that this study as well as other similar emerging analyses from India and elsewhere contribute to our rapidly evolving understanding of the differential impacts of the pandemic. These insights should prove useful in designing more effective policy support measures to counteract these effects and chart a path to a robust and inclusive recovery.

Men's almost universally greater tendency to overestimate their abilities is likely the heritage of a long evolutionary urge to achieve the upper hand in the mating game

The Cocksure Conundrum: How Evolution Created a Gendered Currency of Corporate Overconfidence. Richard Ronay, William W. Maddux & William von Hippel. Adaptive Human Behavior and Physiology, Aug 19 2022. https://rd.springer.com/article/10.1007/s40750-022-00197-5

Abstract: Biological differences between men and women mandate that women’s obligatory investment in reproduction is significantly greater than that of men. As a result, women have evolved to be the “choosier” of the two sexes and men have evolved to compete for female choice. To the degree that overconfidence is an effective tool for attracting mates and driving away competitors, greater competition among men suggests that they should express more overconfidence than women. Thus, sexual selection may be the primary reason why overconfidence is typically more pronounced in men than it is in women. Sexual selection may also be a distal, causal factor in what we describe as a cult of overconfidence pervading modern organizations and institutions. Whereas overconfidence was once regulated and constrained by features of ancestral life, levels of social mobility and accountability in contemporary society and modern organizations make it increasingly difficult to keep this gendered bias in check.

Why are People Overconfident?

Psychological explanations for the widespread tendency towards self-aggrandizement have focused primarily on intrapersonal hedonic benefits, such as higher self-esteem for those who believe they are better than others, and reduced reactivity to stressful events (e.g., Dunning et al., 1995; Taylor & Brown, 1988). An alternative possibility, however, is that overconfidence may be an evolved strategy of considerable utility for achieving status and other types of social currency, such as alliance formation, persuasion and influence, romantic attraction, and ultimately reproduction (von Hippel & Trivers, 2011a).

Individual differences in traits that lead to differential “fitness” within a given ecology result in reproductive variance (i.e., natural selection; Darwin, 1859; Andersson & Iwassa, 1996)). As a result, certain individuals’ expressed traits enable them to leave a greater genetic footprint than that of others. Across generations, this process leads to a proliferation of whatever genes assist in survival and reproduction. And so the footprint grows. The pan-cultural nature of the overconfidence bias (Sedikides et al., 2003) suggests that it may well be one such adaptive trait, selected for over many thousands of generations (Johnson & Fowler, 2011), likely predating the separation of our hominin ancestors from the ancestors of modern chimpanzees (e.g., Moore et al., 2009; Noë et al., 1980). Indeed, Daniel Kahneman speaks of overconfidence as being fundamentally built into the structures of human reasoning (Shariatmadari, 2015).

Given that overconfidence can lead to faulty assessments of one’s circumstances, and hence potentially perilous decisions, it seems odd that overconfidence might have provided an advantage in the context of natural selection. Believing oneself single-handedly capable of bringing down a woolly mammoth was unlikely to have been a winning attitude for our ancestors. Nonetheless, in competitive settings marked by uncertainty, overconfidence has the potential to maximize individual outcomes, so long as the associated costs of failure are outweighed by the benefits of possible success (Johnson & Fowler, 2011; Számadó, 2000). In other words, when the potential gains of achieving a particular goal outweigh the potential costs of failing, risky strategies such as overconfidence have adaptive utility (Adams & Mesterton-Gibbons, 1995; Számadó, 2003).

This perspective is consistent with Error Management Theory (Haselton & Buss, 2000), which predicts the emergence of psychological biases when; (1) the decision had recurrent impacts on fitness (reproductive success), (2) the decision is based on uncertain information, (3) the costs of false positives and false negatives were recurrently asymmetrical over evolutionary time. Overconfidence in one’s abilities meet these criteria quite well under many circumstances.

First, overconfidence potentially impacts fitness by helping individuals compete for sexual opportunity (Murphy et al., 2015) as well as other material and social resources that contribute to reproduction, such as status, prestige, and material rewards (e.g., Henrich & Gil-White, 2001). Second, uncertainty would have been a necessary condition for overconfidence to evolve, as certainty does away with the need for competition and signaling. In such cases, the strongest or most obviously qualified rival simply takes the desired resource. Indeed, as the uncertainty of contested outcomes increases, so too does the utility of overconfidence (Johnson & Fowler, 2011). Third, the costs in lost opportunities associated with being underconfident, or even accurate, are often greater than the costs associated with being overconfident, particularly when people compete with each other over limited resources (Soldà et al., 2021).

As a result of these processes, in situations where the potential gains of overconfidence outweigh the potential risks of overclaiming, overconfident individuals may have an advantage. If so, then overconfident displays may be a functional adaptation that help individuals acquire material and social benefits, depending on the relative magnitude of the risks and rewards that a given situation affords (Adams & Mesterton-Gibbons, 1995; Számadó, 2000, 2003). Consistent with the above reasoning, overconfident people gain a host of social and material benefits, such as increased perceptions of competence and a rise in social status and perceived leadership potential (Anderson et al., 2012; Ronay et al., 2019). As status increases, physiological markers of stress such as cortisol decrease (Sherman & Mehta, 2020) and dopamine sensitivity increases (Morgan et al., 2002), providing proximate, secondary mechanisms for the relationship between overconfidence and the maintenance of positive affect in response to social stressors (Ronay et al., 2019). Thus, it comes as no surprise that overconfidence is selected for in CEO appointments, despite the higher probability of overconfident leaders initiating value-destroying investments (Goel & Thakor, 2008) and financial reporting fraud (Schrand & Zechman, 2012). And perhaps, as we outline below, no surprise that fewer than 5% of CEO positions in the US and Europe are held by women (Edgecliffe-Johnson, 2018).

Why are Overconfident People So Often Men?

This distally focused, status-enhancing account of overconfidence has at least one important moderating factor: The available evidence strongly suggests that men tend to be more overconfident than women. For example, men exhibit more overconfidence than women in academic achievement (Bengtsson et al., 2005), finance and trading (Cueva et al., 2019; Prince, 1993), conflict and competitions (Johnson et al., 2006; Niederle & Vesterlund, 2007), science and mathematics (Ehrlinger & Dunning, 2003; Hyde et al., 1990), past performance (Reuben et al., 2012), intelligence (Steinmayr & Spinath, 2009), and on general knowledge and cognitive tasks (O'Laughlin & Brubaker, 1998; Pallier, 2003). By way of example, in one study, 70% of men and 30% of women, overestimated their work performance and professional skills (Lindeman et al., 1995). While under-confidence is generally the exception, it is more often women than men who err on the side of excessive humility (Lenney, 1977; Small et al., 2007), underestimating their chances of success across various outcomes (Erkut, 1983; Mura, 1987). Even successful women are more likely to attribute their triumphs to external causes, such as others in their team, or luck, rather than to personal aptitude (Campbell & Hackett, 1986; Haynes & Heilman, 2013; LaNoue & Curtis, 1985).

One potential origin of these observed gender differences is biased sampling, in that prior research has often assessed overconfidence in what are considered traditionally masculine domains. However, we argue that overconfidence is not a direct product of domain importance, expertise, or even stereotypicality; rather it is a product of the desire to persuade others of one’s competence in a given domain (Hoffman & Yoeli, 2022; von Hippel & Trivers, 2011a). As such, it is not so much the male-bias of the domains that matters, but the degree to which perceived ability in the domain can help people compete with members of the same sex or attract members of the opposite sex.

Thus, our theorizing also suggests that in contexts that stimulate competition between women, we might see stronger expressions of female overconfidence. For instance, given the importance of social support to female reproductive success (Campbell, 2004; Taylor et al., 2000), we might expect greater female overconfidence in domains related to emotional intelligence, such as empathy (Muthukrishna et al., 2018). And given that attractiveness is a primary dimension of competition for women (Blake et al., 2018; Buss, 1989), we might also see greater overconfidence in attractiveness among women than among men. A finding that is potentially consistent with this possibility is that the correlation between self- and other-ratings of physical attractiveness is substantially lower for women (r = 0.29) than it is for men (r = 0.53) (Marcus & Miller, 2003; see also Pereira et al., 2019).

Despite these possibilities, there are two important caveats that suggest male overconfidence is more important than female overconfidence in attracting a mate. First, with greater variability on a trait, competition for that trait becomes more important. In short-term mating the playing field among females is much more equal than it is among males (Brooks, 2021), suggesting that overconfidence is more likely to be wielded by males than females in short-term mating contexts. In long-term mating, competition among females is more focused on male traits that confer status, and as such, we might expect female status competition to increase with greater variability in male status and income. Support for this prediction can be seen in the finding that women’s self-sexualization occurs to a greater extent in environments that are economically unequal (Blake et al., 2018). Maximizing one’s beauty is a fruitful strategy for attracting high-status male partners (Udry & Eckland, 1984), which historically, has been an important strategy (indeed, sometimes the only strategy) for female survival and social mobility (Blake & Brooks, 2019).

But this possibility leads to our second point, which is that competition among females for long term mates is more focused on male traits that are not directly observable and hence can only be detected with greater uncertainty (e.g., the capacity to gain resources and assist in parental care giving; Taylor et al., 2000). As noted above, uncertainty magnifies the impact of overconfidence. As a consequence, overconfidence has more potential to enhance perceptions of important male traits (such as competence) than it does to enhance perceptions of important female traits (such as physical attractiveness). Perhaps for this reason, Blake (2018) finds that expenditure at beauty salons and women’s clothing stores also covaries with economic inequality, as adornments may be a more viable means of amplifying physical attractiveness than overconfidence. Women’s relative overuse of image-enhancing filters and photo editing (Dhir et al., 2016) may stem from similar motivations. The bottom line here is that males’ internal assets are more readily distorted via overconfident claims.

These differences in adaptive pressures are not unique to humans, and although cognitive tools such as language, theory of mind, and episodic foresight have dramatically enhanced the scope of human deception (Dor, 2017; Suddendorf et al., 2022), false signaling in the context of sexual competition is widespread. For instance, Noë et al. (1980) examined the role of dominance in explaining social rank within chimpanzee hierarchies, identifying three categories of dominance displays – agonistic, bluff, and competitive. They found that male chimpanzee’s social rank to be tied to displays of agonistic dominance (direct physical dominance) and bluff displays (closest to overconfidence). Females social rank was linked only with dominance in competition for space – such as giving way when another is approaching; and social competition – such as refraining from interacting with another partner because another chimp usually acts as partner to the third. Consistent with the human data, overconfidence has the greatest utility in the context of agonistic confrontations and bluff displays.

We can see similar effects further afield from our genetic roots: consider male fig wasps who signal their fighting ability during territorial competitions by displaying their impressive mandibles (Moore et al., 2009). Wasps with large mandibles are intimidating as they can inflict significant damage on opponents. Capitalizing on this advantage, there is an atypical male phenotype that develops mandibles 50% larger than expected for body size. These males are competitive signalers and engage in fewer fights than typical males but have higher mating success. Nonetheless, when compelled to combat, they fare poorly and incur more injuries than a typical male. Taken together, these examples from our near and distant cousins suggest that male sexual competition frequently takes the form of exaggerated signaling, a strategy that may be well served by self-deceptive overconfidence (see Angilletta et al., 2019).