Knowledge that Transforms

We conducted a preregistered field experiment examining racial discrimination in tie formation on social media. We randomly assigned research accounts varying on race (Black, White) and politics (liberal/Democrat, conservative/Republican, neutral) to follow a politically balanced sample of Twitter (i.e., X) users ( N = 5,951) who were unaware they were in a research study. We examined three predictions from the social and political psychology literatures: i) individuals favor White over Black targets, ii) this tendency is stronger for conservatives/Republicans than for liberals/Democrats, and iii) greater discrimination by conservatives/Republicans is explained by the assumption that racial minorities are liberal/Democrat. We found evidence that individuals were less likely to reciprocate social ties with Black accounts than White accounts. However, this tendency was not moderated by individuals’ political orientation, shared partisanship, or partisan mismatch. In sum, this work provides field experimental evidence for racial discrimination in tie formation on social media by individuals across political backgrounds.

Recently, gender-ambiguous (nonbinary) voices have been added to voice assistants to combat gender stereotypes and foster inclusion. However, if people react negatively to such voices, these laudable efforts may be counterproductive. In five preregistered studies ( N = 3,684 adult participants) we found that people do react negatively, rating products described by narrators with gender-ambiguous voices less favorably than when they are described by clearly male or female narrators. The voices create a feeling of unease, or social disfluency, that affects evaluations of the products being described. These effects are best explained by low familiarity with voices that sound ambiguous. Thus, initial negative reactions can be overcome with more exposure.

Happiness has become one of the most important life goals worldwide. However, does valuing happiness lead to better well-being? This study investigates the effect of valuing happiness on well-being using a population-based longitudinal survey of Dutch adults ( N = 8,331) from 2019 to 2023. Random-intercept cross-lagged panel models indicated that those who valued happiness generally exhibited higher well-being as manifested by life satisfaction, more positive affect, and less negative affect. However, increases in valuing happiness did not result in changes in life satisfaction 1 year later and had mixed emotional consequences (i.e., increasing both positive and negative affect). Additional analyses using fixed-effects models indicated that valuing happiness had contemporaneous positive effects on well-being. These findings indicate that endorsing happiness goals may have immediate psychological benefits but may not necessarily translate into long-term positive outcomes.

The neural mechanisms underpinning the dynamic switching of a listener's attention between speakers are not well understood. Here we addressed this issue in a natural conversation involving 21 triadic adult groups. Results showed that when the listener's attention dynamically switched between speakers, neural synchronization with the to-be-attended speaker was significantly enhanced, whereas that with the to-be-ignored speaker was significantly suppressed. Along with attention switching, semantic distances between sentences significantly increased in the to-be-ignored speech. Moreover, neural synchronization negatively correlated with the increase in semantic distance but not with acoustic change of the to-be-ignored speech. However, no difference in neural synchronization was found between the listener and the two speakers during the phase of sustained attention. These findings support the attenuation model of attention, indicating that both speech signals are processed beyond the basic physical level. Additionally, shifting attention imposes a cognitive burden, as demonstrated by the opposite fluctuations of interpersonal neural synchronization.

Gender diversity signals inclusivity, but meta-analyses suggest that it does not boost individual or group performance. This research examined whether a social-psychological intervention can unlock the benefits of gender diversity on college physics students’ social and academic outcomes. Analyses of 124 introductory physics classrooms at a large research institution in the eastern United States ( N = 3,605) indicated that in classrooms doing “business as usual,” cross-gender collaboration was infrequent, there was a substantial gender gap in physics classroom belonging, and classroom gender diversity had no effect on performance. The ecological-belonging intervention aimed to establish classroom norms that adversity in the course is normal and surmountable. In classrooms receiving the intervention, cross-gender interaction increased 51%, the gender gap in belonging was reduced by 47%, and higher classroom diversity was associated with higher course grades and 1-year grade point average for both men and women. Addressing contextual belongingness norms may help to unlock the benefits of diversity.

The current study investigated how autistic traits modulate peer interactions using functional near-infrared spectroscopy (fNIRS) hyperscanning. Across three experiments, we tested the effect of copresence, joint activity, and a tangible goal during cooperative interactions on interbrain coherence (IBC) in school-aged children between 9 and 11 years old. Twenty-three dyads of children watched a video alone or together in Experiment 1, engaged in joint or self-paced book reading in Experiment 2, and pretended to play a Jenga game or played for real in Experiment 3. We found that all three formats of social interactions increased IBC in the frontotemporoparietal networks, which have been reported to support social interaction. Further, our results revealed the shared and unique interbrain connections that were predictive of the lower and higher parent-reported autism-spectrum quotient scores, which indicated child autistic traits. Results from a convergence of three experiments provide the first evidence to date that IBC is modulated by child autistic traits.

1,264 U.S.-based adults) demonstrating that people's interest in discussing important but potentially divisive topics is guided by their expectations about how positively the conversation will unfold, leaving them more interested in having a conversation with someone who agrees versus disagrees with them. People's expectations about their conversations, however, were systematically miscalibrated such that people underestimated how positive these conversations would be-especially in cases of disagreement. Miscalibrated expectations stemmed from underestimating the degree of common ground that would emerge in conversation and from failing to appreciate the power of social forces in conversation that create social connection. Misunderstanding the outcomes of conversation could lead people to avoid discussing disagreements more often, creating a misplaced barrier to learning, social connection, free inquiry, and free expression.

Working memory has been comprehensively studied in sensory domains, like vision, but little attention has been paid to how motor information (e.g., kinematics of recent movements) is maintained and manipulated in working memory. “Motor working memory” (MWM) is important for short-term behavioral control and skill learning. Here, we employed tasks that required participants to encode and recall reaching movements over short timescales. We conducted three experiments ( N = 65 undergraduates) to examine MWM under varying cognitive loads, delays, and degrees of interference. The results support a model of MWM that includes an abstract code that flexibly transfers across effectors, and an effector-specific code vulnerable to interfering movements, even when interfering movements are irrelevant to the task. Neither code was disrupted by increasing visuospatial working memory load. These results echo distinctions between representational formats in other domains, suggesting that MWM shares a basic computational structure with other working memory subsystems.

What makes faces seem trustworthy? We investigated how racial prejudice predicts the extent to which perceivers employ racially prototypical cues to infer trustworthiness from faces. We constructed participant-level computational models of trustworthiness and White-to-Black prototypicality from U.S. college students’ judgments of White (Study 1, N = 206) and Black–White morphed (Study 3, N = 386) synthetic faces. Although the average relationships between models differed across stimuli, both studies revealed that as participants’ anti-Black prejudice increased and/or intergroup contact decreased, so too did participants’ tendency to conflate White prototypical features with trustworthiness and Black prototypical features with untrustworthiness. Study 2 ( N = 324) and Study 4 ( N = 397) corroborated that untrustworthy faces constructed from participants with pro-White preferences appeared more Black prototypical to naive U.S. adults, relative to untrustworthy faces modeled from other participants. This work highlights the important role of racial biases in shaping impressions of facial trustworthiness.

Even if the scene before our eyes remains static for some time, we might explore it differently compared with how we examine static images, which are commonly used in studies on visual attention. Here we show experimentally that the top-down expectation of changes in natural scenes causes clearly distinguishable gaze behavior for visually identical scenes. We present free-viewing eye-tracking data of 20 healthy adults on a new video dataset of natural scenes, each mapped for its potential for change (PfC) in independent ratings. Observers looking at frozen videos looked significantly more often at the parts of the scene with a high PfC compared with static images, with substantially higher interobserver coherence. This viewing difference peaked right before a potential movement onset. Established concepts like object animacy or salience alone could not explain this finding. Images thus conceal experience-based expectations that affect gaze behavior in the potentially dynamic real world.