Knowledge that Transforms

The cognitive reflection test (CRT) measures reliance on intuitive thinking versus deliberate reasoning and predicts important real-world outcomes. Prior research has suggested that testosterone administration impaired CRT performance, but follow-up studies produced null results. To provide a rigorous test, we conducted a large, preregistered, double-blind, placebo-controlled experiment, unprecedented in size, with 1,000 adult men, as part of an adversarial collaboration. Participants received a single dose of intranasal testosterone or placebo, completed the CRT, and rated their confidence level. We found an insignificant treatment effect on the CRT, with the point estimate in the opposite direction of the original hypothesis (β LOGIT = 0.118, 95% confidence interval (CI) = [−0.099, 0.335]). In a second primary test, we found a significant negative treatment effect on confidence (β LOGIT = −0.329, 95% CI = [−0.558, −0.100]), which is also the opposite of our prediction. Our findings challenge earlier claims about testosterone’s cognitive effects and highlight the importance of high-powered replications. Long-term or developmental testosterone effects remain potentially important but difficult to study.

Researchers have long debated whether self-esteem is associated with aggression. In this preregistered research, we tested the effects of self-esteem on aggression by using statistical models that control for unmeasured time-invariant confounders. Data came from a multi-wave longitudinal study of 674 Mexican-origin families, including multi-informant assessments of children, mothers, and fathers at 1- or 2-year intervals. There was no evidence of systematic self-esteem effects on aggression, and the results held when we controlled for narcissism and when the influence of shared-method variance could be ruled out. Also, there was little evidence for effects in the reverse direction, that is, from engaging in aggression on self-esteem. One limitation was that in most cases it was not possible to test whether the self-esteem effects were curvilinear because of the nonconvergence of these models. Overall, the findings do not support either low or high self-esteem as a risk factor for aggression.

We present the results of a replication of Study 2 from Ariely and Wertenbroch on the role of deadlines in mitigating procrastination. We show that our results do not replicate those of the original article. In our replication, with adult participants enrolled at a large public university in the United States, changes in the deadlines had a negligible effect on the three performance metrics and several survey metrics used in the original study. Evenly spaced deadlines, externally imposed on participants by the experimenters, did not stand out for their effectiveness in reducing procrastination in participants. The data further indicate consistency with several patterns of participant behavior that should be expected irrespective of our main replication results.

Americans readily identify with class labels, such as working class and middle class . In turn, these identities affect their social affiliations, cultural values, and physical health. Despite theoretical predictions that class identity can change, little work has empirically examined the long-term malleability of class identity. Here we ask, can class identity change in the long term? And if so, when? We tested this question by examining whether the 2008 Great Recession changed how Americans viewed their social and economic standing in society—that is, their class identity. In three of four data sets (total N = 164,296), we found that the 2008 Great Recession shifted Americans toward identifying as a lower class. We discuss the implications of these results for theories of the formation of class identity and for the political and social development of the United States following 2008.

To navigate complex physical environments, animals keep track of the spatial relations among objects using various reference frames, both body-based (e.g., left/right) and environment-based (e.g., east/west), but how these spatial representations interact remains unresolved. Whereas neuroscientific findings show habitual integration across reference frames, psycholinguistic accounts suggest humans use one reference frame at a time, as in speech. This article examines whether people spontaneously use two reference frames in the same action. When placing a single object in a two-dimensional array, adult participants ( N = 110) routinely used an environment-based frame to determine the object’s left–right position while using a body-based frame to determine its front–back position at the same time. Such hybrid responses were prevalent among both Indigenous Tsimane’ and educated U.S. participants, suggesting that people across cultures habitually construct compound cognitive maps to represent the multidimensional spatial relations that compose natural settings.

Recognition memory refers to the process of distinguishing between previously experienced and novel events. Apart from the objective quality of stored memories, recognition depends on the retrieval context produced by all items (foils) presented together with actually memorized targets and causing confusion. Memory models often conceptualize target-foil confusability via distances in psychological spaces where greater confusability originates from shorter interitem distances. We tested whether recognition spaces change when other foils are added to the retrieval context or when target memory strength is changed ( N = 1,311 adults). Using signal-detection modeling, we found that separately measured distances, d ′s, from each foil to the target provide a good linear prediction of those distances for all foils being presented together against that target. Those predictions stay accurate even when the absolute distances are scaled up or down because of a change in memory strength. This suggests strong metric invariance of spaces used for recognition decisions under variable retrieval contexts.

In seven studies, we investigated how reporting partial vote counts influences perceptions of election legitimacy. Beliefs in election fraud, as in the 2020 U.S. presidential election, may be fueled by the cumulative redundancy bias (CRB), which skews perceptions toward early leaders in partial vote counts. In line with this prediction, participants (Prolific adult participants from the United States and the United Kingdom) consistently rated early leaders more favorably and were more likely to suspect fraud when the eventual winner gained a late lead. This effect persisted across simulated elections (Studies 1–3) and real-world vote counts from the 2020 election in Georgia (Study 4). It is important to note that fraud suspicions already arose before the count was completed (Study 5) and persisted despite explanatory interventions (Study 6). Partisanship did not eliminate the CRB’s influence on fraud beliefs (Study 7). Our findings suggest that the sequential reporting of vote counts may amplify false perceptions of election fraud and could be mitigated by revising how results are communicated.

Gender differences in occupational interests are often assumed to reflect sex differences in empathizing or systemizing preferences. Do such essentialized explanations lead people to provide gender-biased learning affordances that constrain women’s career interests? In Study 1 ( N = 292), North American STEM professionals endorsing a biologically essentialized (vs. sociocultural) explanation for gender differences in occupational interests provided women (men) with more empathizing (systemizing) learning affordances in a mock management task. Study 2 replicated these gendered affordances by experimentally manipulating essentialized explanations ( N = 379; participants were North American men with management experience in male-dominated fields). In Study 3, North American undergraduate women ( N = 300) who received gendered learning affordances reported greater interest in, and possible alignment with, empathizing work assignments, whereas those who received countergendered affordances reported greater interest in, and possible alignment with, systemizing assignments. These results reveal that gender-essentialist beliefs can foster self-fulfilling gender gaps in occupational interests.

= 2,524 U.S.-based adults recruited from the University of California, Berkeley, or Amazon Mechanical Turk) provide support for doubling-back aversion, a reluctance to pursue more efficient means to a goal when they entail undoing progress already made. These effects emerged in diverse contexts, both as participants physically navigated a virtual-reality world and as they completed different performance tasks. Doubling back was decomposed into two components: the deletion of progress already made and the addition to the proportion of a task that was left to complete. Each contributed independently to doubling-back aversion. These effects were robustly explained by shifts in subjective construals of both one's past and future efforts that would result from doubling back, not by changes in perceptions of the relative length of different routes to an end state. Participants' aversion to feeling their past efforts were a waste encouraged them to pursue less efficient means. We end by discussing how doubling-back aversion is distinct from established phenomena (e.g., the sunk-cost fallacy).

Much of the previous research examining sex differences in human mate preferences has relied exclusively on heterosexual participants. Consequently, prior work overlooks a critical limitation: In heterosexual populations, participant sex and partner sex are perfectly confounded. Here, we tease apart this fundamental problem by separately examining ideal preferences for male and female partners across two studies—one using a large bisexual sample ( n = 442) and another using a sample of both bisexual and heterosexual participants ( n = 380). The results revealed that sex differences in mate preferences were largely driven by the participants’ own sex. However, both males and females set higher standards overall for the traits of male partners. These findings suggest that a person’s mate-preference psychology is shaped by both one’s own sex and the sex of the target being evaluated. More broadly, these results expand our understanding of the proximate psychology underlying human mate preferences.