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Recent studies report that socioeconomic status (SES) correlates with brain structure. Yet, such findings are variable and little is known about underlying causes. We present a well-powered voxel-based analysis of grey matter volume (GMV) across levels of SES, finding many small SES effects widely distributed across the brain, including cortical, subcortical and cerebellar regions. We also construct a polygenic index of SES to control for the additive effects of common genetic variation related to SES, which attenuates observed SES-GMV relations, to different degrees in different areas. Remaining variance, which may be attributable to environmental factors, is substantially accounted for by body mass index, a marker for lifestyle related to SES. In sum, SES affects multiple brain regions through measurable genetic and environmental effects.One-sentence SummarySocioeconomic status is linked with brain anatomy through a varying balance of genetic and environmental influences.

Additional co-authors: Ivan Ropovik, Balazs Aczel, Lena F. Aeschbach, Luca Andrighetto, Jack D. Arnal, Holly Arrow, Peter Babincak, Bence E. Bakos, Gabriel Banik, Ernest Baskin, Radomir Belopavlovic, Michael H. Bernstein, Michal Bialek, Nicholas G. Bloxsom, Bojana Bodroža, Diane B. V. Bonfiglio, Leanne Boucher, Florian Bruhlmann, Claudia C. Brumbaugh, Erica Casini, Yiling Chen, Carlo Chiorri, William J. Chopik, Oliver Christ, Antonia M. Ciunci, Heather M. Claypool, Sean Coary, Marija V. Cˇolic, W. Matthew Collins, Paul G. Curran, Chris R. Day, Anna Dreber, John E. Edlund, Filipe Falcao, Anna Fedor, Lily Feinberg, Ian R. Ferguson, Maire Ford, Michael C. Frank, Emily Fryberger, Alexander Garinther, Katarzyna Gawryluk, Kayla Ashbaugh, Mauro Giacomantonio, Steffen R. Giessner, Jon E. Grahe, Rosanna E. Guadagno, Ewa Halasa, Rias A. Hilliard, Joachim Huffmeier, Sean Hughes, Katarzyna Idzikowska, Michael Inzlicht, Alan Jern, William Jimenez-Leal, Magnus Johannesson, Jennifer A. Joy-Gaba, Mathias Kauff, Danielle J. Kellier, Grecia Kessinger, Mallory C. Kidwell, Amanda M. Kimbrough, Josiah P. J. King, Vanessa S. Kolb, Sabina Kolodziej, Marton Kovacs, Karolina Krasuska, Sue Kraus, Lacy E. Krueger, Katarzyna Kuchno, Caio Ambrosio Lage, Eleanor V. Langford, Carmel A. Levitan, Tiago Jesse Souza de Lima, Hause Lin, Samuel Lins, Jia E. Loy, Dylan Manfredi, Łukasz Markiewicz, Madhavi Menon, Brett Mercier, Mitchell Metzger, Venus Meyet, Jeremy K. Miller, Andres Montealegre, Don A. Moore, Rafal Muda, Gideon Nave, Austin Lee Nichols, Sarah A. Novak, Christian Nunnally, Ana Orlic, Anna Palinkas, Angelo Panno, Kimberly P. Parks, Ivana Pedovic, Emilian Pekala, Matthew R. Penner, Sebastiaan Pessers, Boban Petrovic, Thomas Pfeiffer, Damian Pienkosz, Emanuele Preti, Danka Puric, Tiago Ramos, Jonathan Ravid, Timothy S. Razza, Katrin Rentzsch, Juliette Richetin, Sean C. Rife, Anna Dalla Rosa, Kaylis Hase Rudy, Janos Salamon, Blair Saunders, Przemyslaw Sawicki, Kathleen Schmidt, Kurt Schuepfer, Thomas Schultze, Stefan Schulz-Hardt, Astrid Schutz, Ani N. Shabazian, Rachel L. Shubella, Adam Siegel, Ruben Silva, Barbara Sioma, Lauren Skorb, Luana Elayne Cunha de Souza, Sara Steegen, L. A. R. Stein, R. Weylin Sternglanz, Darko Stojilovic, Daniel Storage, Gavin Brent Sullivan, Barnabas Szaszi, Peter Szecsi, Orsolya Szoke, Attila Szuts, Manuela Thomae, Natasha D. Tidwell, Carly Tocco, Ann-Kathrin Torka, Francis Tuerlinckx, Wolf Vanpaemel, Leigh Ann Vaughn, Michelangelo Vianello, Domenico Viganola, Maria Vlachou, Ryan J. Walker, Sophia C. Weissgerber, Aaron L. Wichman, Bradford J. Wiggins, Daniel Wolf, Michael J. Wood, David Zealley, Iris Žeželj, Mark Zrubka, and Brian A. Nosek

As part of the Many Labs 5 project, we ran a replication of van Dijk, van Kleef, Steinel, and van Beest’s (2008) study examining the effect of emotions in negotiations. They reported that when the consequences of rejection were low, subjects offered fewer chips to angry bargaining partners than to happy partners. We ran this replication under three protocols: the protocol used in the Reproducibility Project: Psychology, a revised protocol, and an online protocol. The effect averaged one ninth the size of the originally reported effect and was significant only for the revised protocol. However, the difference between the original and revised protocols was not significant.

We propose that autonomy is a crucial aspect of consumer choice. We offer a definition that situates autonomy among related constructs in philosophy and psychology, contrast actual with perceived autonomy in consumer contexts, examine the resilience of perceived autonomy, and sketch out an agenda for research into the role of perceived autonomy in an evolving marketplace increasingly characterized by automation.

Android robots that resemble humans closely, but not perfectly, can provoke negative feelings of dislike and eeriness in humans (the “Uncanny Valley” effect). We investigated whether category confusion between the perceptual categories of “robot” and “human” contributes to Uncanny Valley aversion. Using a novel, validated corpus of 182 images of real robot and human faces, we precisely estimated the shape of the Uncanny Valley and the location of the perceived robot/human boundary. To implicitly measure confusion, we tracked 358 participants’ mouse trajectories as they categorized the faces. We observed a clear Uncanny Valley, though with some interesting differences from standard theoretical predictions; the initial apex of likability for highly mechanical robots indicated that these robots were still moderately dislikable, and the Uncanny Valley itself was positioned closer to the mechanical than to the human-like end of the spectrum. We also observed a pattern of categorization suggesting that humans do perceive a categorical robot/human boundary. Yet in contrast to predictions of the category confusion mechanism hypothesis, the locations of the Uncanny Valley and of the category boundary did not coincide, and mediation analyses further failed to support a mechanistic role of category confusion. These results suggest category confusion does not explain the Uncanny Valley effect.

We study dynamic unstructured bargaining with deadlines and one-sided private information about the amount available to share (the “pie size”). Using mechanism design theory, we show that given the players’ incentives, the equilibrium incidence of bargaining failures (“strikes”) should increase with the pie size, and we derive a condition under which strikes are efficient. In our setting, no equilibrium satisfies both equality and efficiency in all pie sizes. We derive two equilibria that resolve the trade-off between equality and efficiency by favoring either equality or efficiency. Using a novel experimental paradigm, we confirm that strike incidence is decreasing in the pie size. Subjects reach equal splits in small pie games (in which strikes are efficient), while most payoffs are close to either the efficient or the equal equilibrium prediction, when the pie is large. We employ a machine learning approach to show that bargaining process features recorded early in the game improve out-of-sample prediction of disagreements at the deadline. The process feature predictions are as accurate as predictions from pie sizes only, and adding process and pie data together improves predictions even more. Data are available at https://doi.org/10.1287/mnsc.2017.2965 . This paper was accepted by Uri Gneezy, behavioral economics.

Humans survive and thrive through social exchange. Yet, social dependency also comes at a cost. Perceived social isolation, or loneliness, affects physical and mental health, cognitive performance, overall life expectancy, and increases vulnerability to Alzheimer's disease-related dementias. Despite severe consequences on behavior and health, the neural basis of loneliness remains elusive. Using the UK Biobank population imaging-genetics cohort (n = ~40,000, aged 40-69 years when recruited, mean age = 54.9), we test for signatures of loneliness in grey matter morphology, intrinsic functional coupling, and fiber tract microstructure. The loneliness-linked neurobiological profiles converge on a collection of brain regions known as the 'default network'. This higher associative network shows more consistent loneliness associations in grey matter volume than other cortical brain networks. Lonely individuals display stronger functional communication in the default network, and greater microstructural integrity of its fornix pathway. The findings fit with the possibility that the up-regulation of these neural circuits supports mentalizing, reminiscence and imagination to fill the social void.

It has been suggested that there are two distinct and parallel mechanisms for controlling instrumental behavior in mammals: goal-directed actions and habits. To gain an understanding of how these two systems interact to control behavior, it is essential to characterize the mechanisms by which the balance between these systems is influenced by experience. Studies in rodents have shown that the amount of training governs the relative expression of these two systems: behavior is goal-directed following moderate training, but the more extensively an instrumental action is trained, the more it becomes habitual. It is less clear whether humans exhibit similar training effects on the expression of goal-directed and habitual behavior, as human studies have reported contradictory findings. To tackle these contradictory findings, we formed a consortium, where four laboratories undertook a pre-registered experimental induction of habits by manipulating the amount of training. There was no statistical evidence for a main effect of the amount of training on the formation and expression of habits. However, exploratory analyses suggest a moderating effect of the affective component of stress on the impact of training over habit expression. Participants who were lower in affective stress appeared to be initially goal-directed, but became habitual with increased training, whereas participants who were high in affective stress were already habitual even after moderate training, thereby manifesting insensitivity to overtraining effects. Our findings highlight the importance of the role of moderating variables such as individual differences in stress and anxiety when studying the experimental induction of habits in humans.

It has been suggested that there are two distinct and parallel mechanisms for controlling instrumental behavior in mammals: goal-directed actions and habits. To gain an understanding of how these two systems interact to control behavior, it is essential to characterize the mechanisms by which the balance between these systems is influenced by experience. Studies in rodents have shown that the amount of training governs the relative expression of these two systems: Behavior is goal-directed following moderate training, but the more extensively an instrumental action is trained, the more it becomes habitual. It is less clear whether humans exhibit similar training effects on the expression of goal-directed and habitual behavior, as human studies have reported contradictory findings. To tackle these contradictory findings, we formed a consortium, where four laboratories undertook a preregistered experimental induction of habits by manipulating the amount of training. There was no statistical evidence for a main effect of the amount of training on the formation and expression of habits. However, exploratory analyses suggest a moderating effect of the affective component of stress on the impact of training over habit expression. Participants who were lower in affective stress appeared to be initially goal-directed, but became habitual with increased training, whereas participants who were high in affective stress were already habitual even after moderate training, thereby manifesting insensitivity to overtraining effects. Our findings highlight the importance of the role of moderating variables such as individual differences in stress and anxiety when studying the experimental induction of habits in humans.

Research in the field of multisensory perception shows that what we hear can influence what we see in a wide range of perceptual tasks. It is however unknown whether this extends to the visual perception of risk, despite the importance of the question in many applied domains where properly assessing risk is crucial, starting with financial trading. To fill this knowledge gap, we ran interviews with professional traders and conducted three laboratory studies using judgments of financial asset risk as a testbed. We provide evidence that the presence of ambient sound impacts risk perception, possibly due to the combination of facilitatory and synesthetic effects of general relevance to the perception of risk in many species as well as humans. We discuss the implications of our findings for various applied domains (e.g., financial, medical, and military decision-making), and raise new questions for future research.

The second-to-fourth digit ratio (2D:4D) has been associated with sexual dimorphism, with a lower 2D:4D in males. A large body of research has relied on the 2D:4D as a proxy for prenatal androgen exposure, and includes reports of relationships between 2D:4D and a wide range of human traits. Here, we examine the validity of the 2D:4D proxy by studying the association between 2D:4D and classical Congenital Adrenal Hyperplasia (CAH) due to 21-hydroxylase deficiency, a condition characterized by excessive prenatal exposure to androgens during most of the gestational period. To this end, we retrospectively examine 513 serial radiographs of the left hand obtained clinically in 90 youth with classical CAH (45 female) and 70 control youth (31 female). Replicating previous reports, we observe associations of the 2D:4D with sex (lower 2D:4D in males) and age (increase of 2D:4D through development). However, we find no evidence for differences in 2D:4D between CAH and controls (full sample: β = −0.001 (−0.008, 0.006)]; females: β = −0.004 [−0.015, 0.007]; males: β = 0.001, [−0.008, 0.011]). Although our findings do not rule out a small association between the 2D:4D and CAH, they cast doubt on the usefulness of the 2D:4D as a biomarker for prenatal androgen exposure in behavioral research.

Economic preferences may be shaped by exposure to sex hormones around birth. Prior studies of economic preferences and numerous other phenotypic characteristics use digit ratios (2D : 4D), a purported proxy for prenatal testosterone exposure, whose validity has recently been questioned. We use direct measures of neonatal sex hormones (testosterone and oestrogen), measured from umbilical cord blood ( n = 200) to investigate their association with later-life economic preferences (risk preferences, competitiveness, time preferences and social preferences) in an Australian cohort (Raine Study Gen2). We find no significant associations between testosterone at birth and preferences, except for competitiveness, where the effect runs opposite to the expected direction. Point estimates are between 0.05–0.09 percentage points (pp) and 0.003–0.14 s.d. We similarly find no significant associations between 2D : 4D and preferences ( n = 533, point estimates 0.003–0.02 pp and 0.001–0.06 s.d.). Our sample size allows detecting effects larger than 0.11 pp or 0.22 s.d. for testosterone at birth, and 0.07 pp or 0.14 s.d. for 2D : 4D ( α = 0.05 and power = 0.90). Equivalence tests show that most effects are unlikely to be larger than these bounds. Our results suggest a reinterpretation of prior findings relating 2D : 4D to economic preferences, and highlight the importance of future large-sample studies that permit detection of small effects.

How do features of movie content relate to the psychological makeup of the audiences they attract? We study this question by employing advanced analytical tools to a new rich dataset that combines detailed characterizations of movies and their plots with personality measures of social-media users who “liked” them. We identify novel associations between movie features such as quality, revenue and genre, and the personality dimensions of their fans. We then use machine-learning to show that movie plots—captured via text—predict the personalities of fans beyond all other variables studied. We further use text analytical methods to quantify how different psychological themes (e.g., leisure) and unique concepts that organically emerge from the data (e.g., adultery) relate to fans’ personalities, and show that movie plots align with the characteristic ways in which their fans think, feel, and behave. For example, films with anxiety have neurotic fans, where social films attract extraverted fans. Our findings provide fine-grained mappings between dimensions of personality and movie preferences, facilitate scalable automated assessment of audience psychographics, and showcase a text-analytic framework for studying how features of multidimensional cultural products relate to psychological characteristics of their consumers.

Knight, McShane, et al. (2020) report three experiments on testosterone’s effect on the Cognitive Reflection Test (CRT). The experiments were designed and executed independently of each other and of our previous work (Nave, Nadler, Zava & Camerer, 2017). We thank Knight, McShane, et al. for conducting these experiments and summarizing their results, and we agree that one experiment is obviously not enough for establishing an empirical fact. The individual experiments and their meta-analytic summary are consistent with both the null hypothesis and Nave et al.’s conclusions (see Table S6 in Knight, McShane, et al.’s Supplemental Material), and there is evidence for variation in effects across experiments. In what follows, we reflect on design differences among the experiments and the collective evidence that their data contain.

The second-to-fourth digit ratio (2D:4D) has been associated with sexual dimorphism, with a lower 2D:4D in males. A large body of research has relied on the 2D:4D as a proxy for prenatal androgen exposure, and includes reports of relationships between 2D:4D and a wide range of human traits. Here, we examine the validity of the 2D:4D proxy by studying the association between 2D:4D and classical Congenital Adrenal Hyperplasia (CAH) due to 21-hydroxylase deficiency, a condition characterized by excessive prenatal exposure to androgens during most of the gestational period. To this end, we retrospectively examine serial radiographs of the left hand obtained clinically in 91 youth with classical CAH (49.5% female) and 70 control youth (44.3% female). Replicating previous reports, we observe associations of the 2D:4D with sex (lower 2D:4D in males), age (increase of 2D:4D through development) and ethnicity (lower 2D:4D in Hispanic individuals). However, we find no evidence for differences in 2D:4D between CAH and controls (full sample: □ = 0.0003 [-0.007, 0.008]; females: □ = −0.004 [-0.015, 0.007]; males: □ = 0.003, [-0.007, 0.013]). Although our findings do not rule out a small association between the 2D:4D and CAH, they cast doubt on the usefulness of the 2D:4D as a biomarker for prenatal androgen exposure in behavioral research.

The ratio of length between the second and fourth fingers (2D:4D) is commonly used as an indicator of prenatal sex hormone exposure. Several approaches have been used to try to validate the measure, including examining 2D:4D in people with congenital adrenal hyperplasia (CAH), a suite of conditions characterised by elevated adrenal androgen production secondary to defective steroidogenesis. We present a systematic review and meta-analysis that examines the relationship between these two variables. Twelve articles relating to nine CAH cohorts were identified, and 2D:4D comparisons have been made between cases and controls in eight of these cohorts. Altogether, at least one 2D:4D variable has been compared between n = 251 females with CAH and n = 358 unaffected females, and between n = 108 males with CAH and n = 204 unaffected males. A previous meta-analysis (Hönekopp and Watson, 2010) reported lower right hand (R2D:4D) and left hand (L2D:4D) digit ratios in patients with CAH relative to sex-matched controls. Our meta-analysis showed the same pattern, with medium effect sizes for R2D:4D and small effect sizes for L2D:4D. Differences of small magnitude were also observed for M2D:4D, and no significant effects were observed for D[R-L]. Notably, the only effects that remained statistically significant when stratified by sex were R2D:4D in males and L2D:4D in females, and the average effect size had reduced by 46.70% since the meta-analysis of Hönekopp and Watson (2010). We also found that individual comparisons in this literature were considerably underpowered, and that patterns of sexual dimorphism in 2D:4D were similar in CAH samples as in typically developing populations. Findings are discussed in relation to the prenatal androgen hypothesis as well as alternative explanations.

A positive relationship between brain volume and intelligence has been suspected since the 19th century, and empirical studies seem to support this hypothesis. However, this claim is controversial because of concerns about publication bias and the lack of systematic control for critical confounding factors (e.g., height, population structure). We conducted a preregistered study of the relationship between brain volume and cognitive performance using a new sample of adults from the United Kingdom that is about 70% larger than the combined samples of all previous investigations on this subject ( N = 13,608). Our analyses systematically controlled for sex, age, height, socioeconomic status, and population structure, and our analyses were free of publication bias. We found a robust association between total brain volume and fluid intelligence ( r = .19), which is consistent with previous findings in the literature after controlling for measurement quality of intelligence in our data. We also found a positive relationship between total brain volume and educational attainment ( r = .12). These relationships were mainly driven by gray matter (rather than white matter or fluid volume), and effect sizes were similar for both sexes and across age groups.

Being able to replicate scientific findings is crucial for scientific progress1,2,3,4,5,6,7,8,9,10,11,12,13,14,15. We replicate 21 systematically selected experimental studies in the social sciences published in Nature and Science between 2010 and 201516,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36. The replications follow analysis plans reviewed by the original authors and pre-registered prior to the replications. The replications are high powered, with sample sizes on average about five times higher than in the original studies. We find a significant effect in the same direction as the original study for 13 (62%) studies, and the effect size of the replications is on average about 50% of the original effect size. Replicability varies between 12 (57%) and 14 (67%) studies for complementary replicability indicators. Consistent with these results, the estimated true-positive rate is 67% in a Bayesian analysis. The relative effect size of true positives is estimated to be 71%, suggesting that both false positives and inflated effect sizes of true positives contribute to imperfect reproducibility. Furthermore, we find that peer beliefs of replicability are strongly related to replicability, suggesting that the research community could predict which results would replicate and that failures to replicate were not the result of chance alone.

In nonhumans, the sex steroid testosterone regulates reproductive behaviors such as fighting between males and mating. In humans, correlational studies have linked testosterone with aggression and disorders associated with poor impulse control, but the neuropsychological processes at work are poorly understood. Building on a dual-process framework, we propose a mechanism underlying testosterone’s behavioral effects in humans: reduction in cognitive reflection. In the largest study of behavioral effects of testosterone administration to date, 243 men received either testosterone or placebo and took the Cognitive Reflection Test (CRT), which estimates the capacity to override incorrect intuitive judgments with deliberate correct responses. Testosterone administration reduced CRT scores. The effect remained after we controlled for age, mood, math skills, whether participants believed they had received the placebo or testosterone, and the effects of 14 additional hormones, and it held for each of the CRT questions in isolation. Our findings suggest a mechanism underlying testosterone’s diverse effects on humans’ judgments and decision making and provide novel, clear, and testable predictions.

A critical component of both economic and perceptual decision making under uncertainty is the belief-formation process. However, most research has studied belief formation in economic and perceptual decision making in isolation. One reason for this separate treatment may be the assumption that there are distinct psychological mechanisms that underlie belief formation in economic and perceptual decisions. An alternative theory is that there exists a common mechanism that governs belief formation in both domains. Here, we test this alternative theory by combining a novel computational modeling technique with two well-known experimental paradigms. We estimate a drift-diffusion model (DDM) and provide an analytical method to decode prior beliefs from DDM parameters. Subjects in our experiment exhibit strong extrapolative beliefs in both paradigms. In line with the common mechanism hypothesis, we find that a single computational model explains belief formation in both tasks and that individual differences in belief formation are correlated across tasks. Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2016.2453 . This paper was accepted by Yuval Rottenstreich, judgment and decision making.

Risen and Gilovich (2008) found that subjects believed that “tempting fate” would be punished with ironic bad outcomes (a main effect), and that this effect was magnified when subjects were under cognitive load (an interaction). A previous replication study (Frank & Mathur, 2016) that used an online implementation of the protocol on Amazon Mechanical Turk failed to replicate both the main effect and the interaction. Before this replication was run, the authors of the original study expressed concern that the cognitive-load manipulation may be less effective when implemented online than when implemented in the lab and that subjects recruited online may also respond differently to the specific experimental scenario chosen for the replication. A later, large replication project, Many Labs 2 (Klein et al. 2018), replicated the main effect (though the effect size was smaller than in the original study), but the interaction was not assessed. Attempting to replicate the interaction while addressing the original authors’ concerns regarding the protocol for the first replication study, we developed a new protocol in collaboration with the original authors. We used four university sites ( N = 754) chosen for similarity to the site of the original study to conduct a high-powered, preregistered replication focused primarily on the interaction effect. Results from these sites did not support the interaction or the main effect and were comparable to results obtained at six additional universities that were less similar to the original site. Post hoc analyses did not provide strong evidence for statistical inconsistency between the original study’s estimates and our estimates; that is, the original study’s results would not have been extremely unlikely in the estimated distribution of population effects in our sites. We also collected data from a new Mechanical Turk sample under the first replication study’s protocol, and results were not meaningfully different from those obtained with the new protocol at universities similar to the original site. Secondary analyses failed to support proposed substantive mechanisms for the failure to replicate.

Previous research points to the heritability of risk-taking behaviour. However, evidence on how genetic dispositions are translated into risky behaviour is scarce. Here, we report a genetically-informed neuroimaging study of real-world risky behaviour across the domains of drinking, smoking, driving, and sexual behaviour, in a European sample from the UK Biobank (N= 12,675). We find negative associations between risky behaviour and grey matter volume (GMV) in distinct brain regions, including amygdala, ventral striatum, hypothalamus, and dorsolateral prefrontal cortex (dlPFC). These effects replicate in an independent sample recruited from the same population (N=13,004). Polygenic risk scores for risky behaviour, derived from a genome-wide association study in an independent sample (N=297,025), are inversely associated with GMV in dlPFC, putamen, and hypothalamus. This relation mediates ~2.2% of the association between genes and behaviour. Our results highlight distinct heritable neuroanatomical features as manifestations of the genetic propensity for risk taking.One Sentence SummaryRisky behaviour and its genetic associations are linked to less grey matter volume in distinct brain regions.

As part of the Many Labs 5 project, we ran a replication of Van Dijk, Van Kleef, Steinel, & Van Beest’s (2008) study “A social functional approach to emotions in bargaining: When communicating anger pays and when it backfires,” which examined the effect of emotions in negotiations. Van Dijk et al. (2008) report that when the consequences of rejection were low, subjects offered fewer chips to angry bargaining partners when compared to happy partners. In the current study, we ran this replication under three protocols: the protocol used in the Replication Project (2015), a revised protocol, and an online protocol.

Replications in psychological science sometimes fail to reproduce prior findings. If replications use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data collection peer review by experts may address shortcomings and increase replicability rates. We selected 10 replications from the Reproducibility Project: Psychology (RP:P; Open Science Collaboration, 2015) in which the original authors had expressed concerns about the replication designs before data collection and only one of which was “statistically significant” (p < .05). Commenters suggested that lack of adherence to expert review and low-powered tests were the reasons that most of these RP:P studies failed to replicate (Gilbert et al., 2016). We revised the replication protocols and received formal peer review prior to conducting new replications. We administered the RP:P and Revised protocols in multiple laboratories (Median number of laboratories per original study = 6.5; Range 3 to 9; Median total sample = 1279.5; Range 276 to 3512) for high-powered tests of each original finding with both protocols. Overall, Revised protocols produced similar effect sizes as RP:P protocols following the preregistered analysis plan (Δr = .002 or .014, depending on analytic approach). The median effect size for Revised protocols (r = .05) was similar to RP:P protocols (r = .04) and the original RP:P replications (r = .11), and smaller than the original studies (r = .37). The cumulative evidence of original study and three replication attempts suggests that effect sizes for all 10 (median r = .07; range .00 to .15) are 78% smaller on average than original findings (median r = .37; range .19 to .50), with very precisely estimated effects.

The capacity to infer others' mental states (known as ‘mind reading’ and ‘cognitive empathy’) is essential for social interactions across species, and its impairment characterizes psychopathological conditions such as autism spectrum disorder and schizophrenia. Previous studies reported that testosterone administration impaired cognitive empathy in healthy humans, and that a putative biomarker of prenatal testosterone exposure (finger digit ratios) moderated the effect. However, empirical support for the relationship has relied on small sample studies with mixed evidence. We investigate the reliability and generalizability of the relationship in two large-scale double-blind placebo-controlled experiments in young men ( n = 243 and n = 400), using two different testosterone administration protocols. We find no evidence that cognitive empathy is impaired by testosterone administration or associated with digit ratios. With an unprecedented combined sample size, these results counter current theories and previous high-profile reports, and demonstrate that previous investigations of this topic have been statistically underpowered.

The impact of testosterone on decision-making is a growing literature, with several reports of economically relevant outcomes. Similar to Wibral et al. (2012), we investigate the effects of exogenous testosterone administration on deception in a double-blind placebo controlled study. Participants (N = 242) were asked to roll a die in private and were paid according to their reported roll, which creates the opportunity to lie about the outcome to increase earnings. We find evidence for self-serving lying in both treatment and control groups and a statistically insignificant negative effect (d = −0.17, 95% CI[−0.42, 0.08]) indicating more honest behavior (i.e., lower reports) following testosterone administration. Although insignificant, the direction was the same as in the Wibral et al. study, and the meta-analytic effect of the two studies demonstrates lower reporting (i.e., more honesty) following testosterone (vs. placebo) administration, significant at the 0.05 level (d = −0.27, 95% CI[−0.49, −0.06]). We discuss how our results and methodology compare with Wibral et al. and identify potential causes for differences in findings. Finally, we consider several plausible connections between testosterone and lying that may be further investigated using alternative methodologies.

People are exposed to persuasive communication across many different contexts: Governments, companies, and political parties use persuasive appeals to encourage people to eat healthier, purchase a particular product, or vote for a specific candidate. Laboratory studies show that such persuasive appeals are more effective in influencing behavior when they are tailored to individuals' unique psychological characteristics. However, the investigation of large-scale psychological persuasion in the real world has been hindered by the questionnaire-based nature of psychological assessment. Recent research, however, shows that people's psychological characteristics can be accurately predicted from their digital footprints, such as their Facebook Likes or Tweets. Capitalizing on this form of psychological assessment from digital footprints, we test the effects of psychological persuasion on people's actual behavior in an ecologically valid setting. In three field experiments that reached over 3.5 million individuals with psychologically tailored advertising, we find that matching the content of persuasive appeals to individuals' psychological characteristics significantly altered their behavior as measured by clicks and purchases. Persuasive appeals that were matched to people's extraversion or openness-to-experience level resulted in up to 40% more clicks and up to 50% more purchases than their mismatching or unpersonalized counterparts. Our findings suggest that the application of psychological targeting makes it possible to influence the behavior of large groups of people by tailoring persuasive appeals to the psychological needs of the target audiences. We discuss both the potential benefits of this method for helping individuals make better decisions and the potential pitfalls related to manipulation and privacy.

In modern human cultures where social hierarchies are ubiquitous, people typically signal their hierarchical position through consumption of positional goods—goods that convey one’s social position, such as luxury products. Building on animal research and early correlational human studies linking the sex steroid hormone testosterone with hierarchical social interactions, we investigate the influence of testosterone on men’s preferences for positional goods. Using a placebo-controlled experiment (N = 243) to measure individuals’ desire for status brands and products, we find that administering testosterone increases men’s preference for status brands, compared to brands of similar perceived quality but lower perceived status. Furthermore, testosterone increases positive attitudes toward positional goods when they are described as status-enhancing, but not when they are described as power-enhancing or high in quality. Our results provide novel causal evidence for the biological roots of men’s preferences for status, bridging decades of animal behavioral studies with contemporary consumer research., Testosterone is believed to be involved in social rank-related behavior. Here, the authors show that one dose of testosterone increases men’s preference for “high status” goods and brands, suggesting a role for testosterone in modern consumer behavior in men.

We thank Eckles et al. (1) for their thoughtful comments. The authors point out that the optimization algorithms of Facebook’s advertising platform constitute a potential confound of campaign outcomes. We agree, in general, that such algorithms could pose a threat to the validity of field studies since they introduce unintended variance across the target audiences. However, as we demonstrate below, it is unlikely that such confounds account for the pattern of results presented in our original research (2). First, the authors point toward “statistically significant” differences in the age and gender distributions of target groups. However, it is important to keep in mind that with sample sizes as … [↵][1]1To whom correspondence should be addressed. Email: sm4409{at}gsb.columbia.edu. [1]: #xref-corresp-1-1

Research over the past decade has shown that various personality traits are communicated through musical preferences. One limitation of that research is external validity, as most studies have assessed individual differences in musical preferences using self-reports of music-genre preferences. Are personality traits communicated through behavioral manifestations of musical preferences? We addressed this question in two large-scale online studies with demographically diverse populations. Study 1 ( N = 22,252) shows that reactions to unfamiliar musical excerpts predicted individual differences in personality—most notably, openness and extraversion—above and beyond demographic characteristics. Moreover, these personality traits were differentially associated with particular music-preference dimensions. The results from Study 2 ( N = 21,929) replicated and extended these findings by showing that an active measure of naturally occurring behavior, Facebook Likes for musical artists, also predicted individual differences in personality. In general, our findings establish the robustness and external validity of the links between musical preferences and personality.

Behavioral neuroscientists have shown that the neuropeptide oxytocin (OT) plays a key role in social attachment and affiliation in nonhuman mammals. Inspired by this initial research, many social scientists proceeded to examine the associations of OT with trust in humans over the past decade. To conduct this work, they have (a) examined the effects of exogenous OT increase caused by intranasal administration on trusting behavior, (b) correlated individual difference measures of OT plasma levels with measures of trust, and (c) searched for genetic polymorphisms of the OT receptor gene that might be associated with trust. We discuss the different methods used by OT behavioral researchers and review evidence that links OT to trust in humans. Unfortunately, the simplest promising finding associating intranasal OT with higher trust has not replicated well. Moreover, the plasma OT evidence is flawed by how OT is measured in peripheral bodily fluids. Finally, in recent large-sample studies, researchers failed to find consistent associations of specific OT-related genetic polymorphisms and trust. We conclude that the cumulative evidence does not provide robust convergent evidence that human trust is reliably associated with OT (or caused by it). We end with constructive ideas for improving the robustness and rigor of OT research.

A positive relationship between brain volume and intelligence has been suspected since the 19th century and empirical studies seem to support this hypothesis. However, this claim is not uncontroversial because of concerns about publication bias and the lack of systematic control for critical confounding factors (e.g., height, population structure). We performed a pre-registered study of the relationship between brain volume and cognitive performance in a new adult population sample from the UK that is about 70% larger than all previous investigations on this subject combined (N=13,608). Our analyses systematically controlled for sex, age, height, socioeconomic status and population structure, and is free of publication bias. We find a robust association between total brain volume and fluid intelligence (r=0.19), which is consistent with previous findings in the literature after controlling for measurement quality of intelligence in our data. We also find a positive relationship with educational attainment (r=0.12). These relationships are mainly driven by grey matter (rather than white matter or fluid volume) and effect sizes are similar for both sexes and across age groups.

Loss aversion is a well-known behavioral regularity in financial decision making, describing humans' tendency to overweigh losses compared to gains of the same amount. Recent research indicates that stress and associated hormonal changes affect loss aversion, yet the underlying neuroendocrine mechanisms are still poorly understood. Here, we investigated the causal influence of two major stress neuromodulators, cortisol and noradrenaline, on loss aversion during financial decision making. In a double-blind, placebo-controlled between-subject design, we orally administered either the α2-adrenergic antagonist yohimbine (increasing noradrenergic stimulation), hydrocortisone, both substances, or a placebo to healthy young men. We tested the treatments' influence on a financial decision-making task measuring loss aversion and risk attitude. We found that both drugs combined, relative to either drug by itself, reduced loss aversion in the absence of an effect on risk attitude or choice consistency. Our data suggest that concurrent glucocorticoid and noradrenergic activity prompts an alignment of reward- with loss-sensitivity, and thus diminishes loss aversion. Our results have implications for the understanding of the susceptibility to biases in decision making.

Psychological and physiological states such as mood, hunger, stress, and sleep deprivation are known to affect decision-making processes and therefore crucially influence consumer behavior. A possible biological mechanism underlying the observed variability of consumer behavior is the context-sensitive variation in the levels of neuromodulators in the brain. In a series of four experimental studies, the authors pharmaceutically reduce the levels of the neurotransmitter serotonin in the brain to diminish the availability of subjects’ cognitive resources. In doing so, they study how serotonin brain levels influence (1) subjects’ tendency to avoid buying and (2) consumers' preference for product options positioned as a compromise in a given choice set rather than for more extreme alternatives (i.e., the compromise effect). Using realistic product choice scenarios in a binding decision framework, they find that a reduction of brain serotonin levels leads to choice deferral and decreases the compromise effect, both as a within-subjects and as a between-subjects choice phenomenon. As such, this study provides neurobiological evidence for the assumption that the compromise effect is the result of deliberate and demanding thought processes rather than intuitive decision making.

The history of humankind is an epic of cooperation, which is ubiquitous across societies and increasing in scale. Much human cooperation occurs where it is risky to cooperate for mutual benefit because successful cooperation depends on a sufficient level of cooperation by others. Here we show that arginine vasopressin (AVP), a neuropeptide that mediates complex mammalian social behaviors such as pair bonding, social recognition and aggression causally increases humans’ willingness to engage in risky, mutually beneficial cooperation. In two double-blind experiments, male participants received either AVP or placebo intranasally and made decisions with financial consequences in the “Stag hunt” cooperation game. AVP increases humans’ willingness to cooperate. That increase is not due to an increase in the general willingness to bear risks or to altruistically help others. Using functional brain imaging, we show that, when subjects make the risky Stag choice, AVP down-regulates the BOLD signal in the left dorsolateral prefrontal cortex (dlPFC), a risk-integration region, and increases the left dlPFC functional connectivity with the ventral pallidum, an AVP receptor-rich region previously associated with AVP-mediated social reward processing in mammals. These findings show a previously unidentified causal role for AVP in social approach behavior in humans, as established by animal research.

The neurohormone oxytocin (OT) has been one the most studied peptides in behavioural sciences over the past two decades. Primarily known for its crucial role in labour and lactation, a rapidly growing literature suggests that intranasal OT (IN-OT) may also play a role in the emotional and social lives of humans. However, the lack of a convincing theoretical framework explaining the effects of IN-OT that would also allow the prediction of which moderators exert their effects and when has raised healthy skepticism regarding the robustness of human behavioural IN-OT research. Poor knowledge of the exact pharmacokinetic properties of OT, as well as crucial statistical and methodological issues and the absence of direct replication efforts, may have lead to a publication bias in the IN-OT literature, with many unpublished studies with null results remaining buried in laboratory drawers. Is there a file drawer problem in IN-OT research? If this is the case, it may also be true in our own laboratory. The present study aims to answer this question, document the extent of the problem and discuss its implications for OT research. For eight studies (including 13 dependent variables overall, as assessed through 25 different paradigms) performed in our laboratory between 2009 and 2014 on 453 subjects, the results obtained were too often not those that were expected. Only five publications emerged from our studies and only one of these reported a null finding. After realising that our publication portfolio has become less and less representative of our actual findings and because the nonpublication of our data might contribute to generating a publication bias in IN-OT research, we decided to retrieve these studies from our drawer and encourage other laboratories to do the same.

Heavy alcohol consumption can have significant deleterious neural consequences, including brain atrophy, neuronal loss, poorer white matter fiber integrity, and cognitive decline. However, the effects of light-to-moderate alcohol consumption on brain structure remain unclear. Here, we examine the associations between alcohol intake and brain structure using multimodal imaging data from 36,678 generally healthy middle-aged and older adults from the UK Biobank, controlling for numerous potential confounds. We find negative associations between alcohol intake and global gray matter volume (GMV) and white matter volume (WMV), which become stronger as intake increases. An examination of the associations between alcohol intake and 139 regional GMV imaging-derived phenotypes (IDPs) and 375 WM microstructure IDPs yielded 304 (59.1%) significant findings, including 125 GMV IDPs that are spread across the brain and 179 WM microstructure IDPs across multiple tract regions. In general, findings comport with the existing literature. However, a daily alcohol intake of as little as one to two units – 250 to 500 ml of a 4% beer or 76 to 146 ml of a 13% wine – is already associated with GMV deficits and altered WMV microstructure, placing moderate drinkers at risk.One Sentence SummaryModerate alcohol intake, consuming one or more daily alcohol units, has adverse effects on brain health.