Just as animals forage for food, humans forage for social connections. People often face a decision between exploring new relationships versus deepening existing ones. This tradeoff, known in optimal foraging theory as the exploration-exploitation tradeoff, is featured prominently in other disciplines such as animal foraging, learning, and organizational behavior. Many of the framework's principles can be applied to humans' choices about their social resources, which we call social exploration/exploitation. Using known principles in the domain of social exploration/exploitation can help social psychologists better understand how and why people choose their relationships, which ultimately affect their health and well-being. In this paper, we discuss the costs and benefits of social exploration and social exploitation. We then synthesize known person- and situation-level predictors of social decision-making, reframing them in the language of the explore-exploit tradeoff. We propose that people explore more when they find it more rewarding and less costly, and when the environment has many opportunities to do so. We conclude by discussing hypotheses generated by applying optimal foraging theory to social decision-making.

How do students' beliefs about the world and their everyday exploratory behaviors change after a mass campus shooting? In the present longitudinal study, an on-campus shooting occurred in the middle of data collection, resulting in an unplanned pre-post quasi-experiment to investigate whether the association between world beliefs and behavior changed after a traumatic event. Over three two-week waves of data collection, with the shooting happening in the middle of the second wave, we measured students' general beliefs about the world (their primal world beliefs), daily physical movement, the activities they were doing, how typical those activities were, and how close participants felt to the people they were with. Unsurprisingly, students exhibited less exploratory movement patterns immediately following the shooting. After the shooting, but not before, safe world belief predicted how much people physically explored their environment, and enticing world belief predicted how varied a person's activities were. Primal world beliefs did not significantly change from before the shooting to after, demonstrating their stability. We speculate that the post-shooting campus environment was more ambiguous than the pre-shooting environment, allowing beliefs about the world to be more strongly associated with behavior.

People’s emotional states often become more similar after social interactions, a process known as emotion contagion. Emotion contagion is considered both a by-product of shared goals and a tool for strengthening social bonds. Although cross-sectional evidence suggests emotion contagion is positively related to bond strength, few studies have investigated this relationship longitudinally as people become acquainted. Perhaps emotion contagion increases as people become closer (a within-dyad effect), reflecting relationship closeness. Or perhaps some dyads have a stable mutual liking and a tendency towards emotion contagion that does not change over time (a between-dyad effect). Our study disentangled these two accounts. Pairs of unacquainted participants had conversations weekly for six weeks over Zoom. Participants reported pre- and post-conversation emotion states and closeness to their partner after each conversation. Emotion contagion, measured in three different ways, declined over time as dyads became interpersonally closer (evidence for a within-dyad effect). This decline may indicate increased comfort with emotional divergence. Notably, dyads that reported greater average interpersonal closeness exhibited larger changes in emotion states during their conversations, aligning with previous between-dyad findings. Thus, the association between emotion contagion and feelings of interpersonal closeness depends on whether we consider change within a dyad or compare between dyads.

During conversations, people face a trade-off between establishing understanding and making interesting and unique contributions. How do people balance this when deciding which concepts to reference, and does it matter how well they know their conversation partner? In the present work, participants made stream-of-consciousness word associations either with a partner or alone—simplified versions of dialogue and monologue. Participants made semantically narrower and more predictable word associations with a stranger than alone (Study 1), suggesting that they constrain their associations to establish mutual understanding. Increasing closeness (Study 2) or having a prior relationship (Study 3) did not moderate this effect. Thus, even during a task that does not depend on establishing mutual understanding, people sacrifice being interesting for the sake of being understood. 

The positivity of goal completion is reinforced through everyday experiences of social praise and instrumental reward. Here we investigated whether, in line with this self-regulatory emphasis, people value completion opportunities in and of themselves. Across six experiments we found that adding an arbitrary completion opportunity to a lower-reward task increased the likelihood that participants would choose to work on that task over a higher-reward alternative that did not offer a completion opportunity. This occurred for extrinsic reward tradeoffs (Experiments 1, 3, 4, and 5) and intrinsic reward tradeoffs (Experiments 2 and 6), and it persisted even when participants explicitly noted the rewards of each task (Experiment 3). We sought but did not find evidence that the tendency is moderated by participants’ stable or momentary level of concern with monitoring multiple responsibilities (Experiments 4 and 5, respectively). We did find that the opportunity to complete the final step in a sequence was particularly attractive: Setting the lower-reward task closer to completion (but with completion still out of reach) did increase its choice share, but setting the lower-reward task with completion distinctly in reach increased its choice share even more (Experiment 6). Together, the experiments imply that people sometimes behave as if they value completion itself. In everyday life, the allure of mere completion may influence the tradeoffs people make when prioritizing their goals.

From ancient time, Homo sapiens moved around in search of a better life. Although the development of agriculture and industrialization no longer necessitates frequently moving to find new food sources, people today still change their residences for a variety of reasons. This article highlights key findings from residential mobility, focusing on its implications for the self, social relationships, societies, and well-being. Generally, residential mobility shifts individual attention away from collective attributes toward personal attributes. It also changes people's relationship styles and preferences, leading individuals to favor wider social networks, more open communication, low-commitment groups, and egalitarian helpers. In addition, it increases tolerance for norm violations and moral deviations. Lastly, residential mobility can explain some cross-national and within-nation variations. This article reviews recent psychological research on residential mobility and then discusses limitations, paradoxical findings, and future directions.