How Relatable
Neural similarity predicts whether strangers become friends
Yixuan Lisa Shen et al.
Nature Human Behaviour, forthcoming
Abstract:
What determines who becomes and stays friends? Many factors are linked to friendship, including physical proximity and interpersonal similarities. Recent work has leveraged neuroimaging to detect similarities among friends by capturing how people process the world around them. However, given the cross-sectional nature of past research, it is unknown if neural similarity precedes friendship or only emerges among friends following social connection. Here we show that similarities in neural responses to movie clips -- acquired before participants met one another -- predicted proximity in a friendship network eight months later (that is, participants with similar responses were more likely to be friends rather than several degrees of separation apart). We also examined changes in distances between participants in their shared social network, which resulted from the formation, persistence and dissolution of friendships, between two months and eight months after they met each other. Compared with people who drifted further apart, people who grew closer over this six-month period had been more neurally similar as strangers. In addition, analyses controlling for sociodemographic similarities showed that whereas these similarities appeared to drive the differences in pre-existing neural similarities between friends and dyads of a social distance of 3, they did not account for the more extensive links between pre-existing neural similarities and the tendency for people to grow closer together, rather than drift farther apart, over time. Thus, whereas some friendships may initially form due to circumstance and dissolve over time, later-emerging and longer-lasting friendships may be rooted in deeper interpersonal compatibilities that are indexed by pre-existing neural similarities. The localization of these results suggests that pre-existing similarities in how people interpret, attend to and emotionally respond to their surroundings are precursors of future friendship and increased social closeness.
Neural basis of cooperative behavior in biological and artificial intelligence systems
Mengping Jiang et al.
Science, forthcoming
Abstract:
Cooperation, the process through which individuals work together to achieve common goals, is fundamental to human and animal societies and increasingly critical in artificial intelligence. Here, we investigated cooperation in mice and artificial intelligence systems, examining how they learn to actively coordinate their actions to obtain shared rewards. We identified key social behavioral strategies and decision-making processes in mice that facilitate successful cooperation. These processes are represented in the anterior cingulate cortex (ACC) and ACC activity causally contributes to cooperative behavior. We extended our findings to artificial intelligence systems by training artificial agents in a similar cooperation task. The agents developed behavioral strategies and neural representations reminiscent of those observed in the biological brain, revealing parallels between cooperative behavior in biological and artificial systems.
Maybe don't say “maybe”: How and why invitees fail to realize that they should not respond to invitations with a “maybe”
Julian Givi et al.
Journal of Experimental Social Psychology, November 2025
Abstract:
People often invite others to join them for social activities. Upon receiving an invitation, an invitee might respond to the inviter with a tentative “maybe.” We examine whether invitees accurately gauge an inviter's preferences when they contemplate replying with a “maybe” (vs. “no”). Across six experiments (five preregistered), we show that invitees often overestimate the likelihood that an inviter would prefer a “maybe” response over a direct “no,” because they underestimate how much more disrespected an inviter feels upon receiving a “maybe” (vs. “no”). We also demonstrate that these mispredictions arise, in part, due to motivated reasoning. Invitees think that replying with a “maybe” (vs. “no”) aligns with what an inviter would find desirable, in part because a “maybe” response serves the invitee's own interests more than a direct decline does. Finally, we illustrate that partly due to their flawed predictions, invitees are more likely to respond with a “maybe” (vs. “no”) even though an inviter would prefer greater decisiveness. The findings contribute to the emerging social psychology of invitations.
Smile and the world smiles (and trusts) with you: Happiness mimicry shapes first impressions
Michal Olszanowski, Aleksandra Tołopiło & Ursula Hess
Emotion, forthcoming
Abstract:
Numerous studies have shown that the processes underlying trait judgments can be influenced by concurrent affect processing. The present project explores the role of emotional mimicry in trait attribution. Across three experiments, we asked participants to assess social characteristics of faces expressing happiness, sadness, and anger. In Experiments 1 and 3, we used facial electromyography to predict participants’ inferences about trustworthiness, confidence, and attractiveness (Experiment 1) or their behaviorally assessed trust by asking participants to share virtual points in a “trust/investment game” (Experiment 3). In Experiment 2, we tested the causal relationship between facial activity and trait judgments. Participants were asked to assess trustworthiness while performing facial movements that either enhanced or inhibited muscle activity during mimicry of given emotional expressions. The results indicate that mimicry of happiness not only predicts but is causally linked to perceptions of trustworthiness -- the stronger the imitation, the more positive the assessments. The results of Experiments 1 and 3 show that increased sadness mimicry is associated with lower trust ratings, although the results of Experiment 2 do not support a causal relationship. Additionally, we confirmed previous observations that people are more likely to mimic affiliative displays (i.e., happiness and sadness) than antagonistic ones (i.e., anger), with happiness being the most likely to be mimicked. In summary, these studies provide evidence that facial mimicry modulates social trait inferences and underscores the functional role of mimicry in social interactions.
The Impact of a Robot’s Agreement (or Disagreement) on Human-Human Interpersonal Closeness in a Two-Person Decision-Making Task
Ting-Han Lin et al.
Computers in Human Behavior, forthcoming
Abstract:
Robots and artificial agents are becoming increasingly integrated into our lives and show promise in assisting people in decision-making tasks. Despite their advantages, robot-assisted decision-making systems may have negative effects on the relationships between human team members. In this work, we examine the influence of the robot’s agreement (or disagreement) on the interpersonal closeness between two participants in a two-person decision-making task. We test the robot’s impact in two experiments: Experiment 1 (N = 172, 86 pairs) with a High Anthropomorphism Robot and Experiment 2 (N = 150, 75 pairs) with a Low Anthropomorphism Robot. For both experiments, we use a 2 x 2 study design to examine how the perceived interpersonal closeness between two participants was influenced by two aspects of robot behavior, namely the valence of the robot’s feedback (positive feedback or negative feedback) and the treatment of the two participants (equal treatment or unequal treatment). Our results demonstrate that interacting with the High Anthropomorphism Robot led to greater interpersonal closeness between participants when the robot provided positive feedback as opposed to negative feedback. The Low Anthropomorphism Robot had a different and opposite effect: interactions with this robot led to greater interpersonal closeness when the robot’s feedback was equal as opposed to unequal and when the robot provided negative feedback as opposed to positive feedback. Our results indicate that robots can shape human-human relationships when indicating their agreement with people’s perspectives in two-person decision-making tasks and that the robot’s influence depends on its appearance and communication style.
Hearing a Feeling: Music Emotion Recognition and Callous-Unemotional Traits in Early Childhood
Yael Paz et al.
Child Development, forthcoming
Abstract:
Music is a powerful medium to study emotion recognition. However, findings are mixed regarding the proficiency of young children to detect emotion conveyed by music. Moreover, we lack knowledge about music emotion recognition and callous-unemotional traits, which portend risk for externalizing problems. The current study examined the performance of 144 children aged 3–5 years old (47.9% female; 34.0% minoritized race/ethnicity) during a music recognition task, with clips conveying happiness, sadness, calmness, or fear. Children showed above-chance accuracy, particularly for high-arousal emotions (happiness, fear), with accuracy increasing from 3 to 5 years old. Children higher on callous-unemotional traits showed poorer emotion recognition, particularly for positively valenced music. Findings underscore the potential for music to promote emotion recognition and social competence skills across development.