Written by Maya Mazumder ‘23
Edited by Elana Balch ‘21.5
Though it’s sometimes hard to believe when faced with an endless cycle of news harping on the failures of society, science tells us that humans are actually an incredibly prosocial species. In fact, our ability to forge cooperative social bonds not just with those closest to us, but also with others on the scale of creating entire governments and nations is part of what makes humans so unique when compared to any other animal. However, researchers have struggled to understand how people balance prosociality, or behaviors that benefit others, with the risk of being exploited. In order for societies to sustain themselves, there must be some mechanism to prevent the most cooperative members of a social network from being taken advantage of too much.
To answer this question, a new study by Elhert et al. turned to middle schoolers. They found that when tracking individual students’ levels of prosociality and their friendships with others over the course of a year, students formed clusters, a phenomena in which cooperative individuals group together to avoid being exposed to as many non-cooperative individuals, allowing them to mitigate the risk of exploitation. Additionally, their data suggested that the formation of these clusters was mediated by social learning, rather than partner choice. In other words, it was not that prosocial students made friends with other prosocial students at the beginning of the year, but rather that students learned to behave more similarly to those they
associated with, eventually leading to distinct clusters.
To show this, the researchers tracked a population of 1,217 middle school students and their relationships with other classmates to map out how student networks changed within a year. By measuring how students rated the strength of their relationship with others in the class and gauging the students’ level of prosociality with a questionnaire, they were able to analyze how these dimensions changed over the course of the year. More specifically, the primary way the researchers gauged students’ levels of prosociality and selfishness was by providing the students with the option to either take a small amount of money for themselves or to share it with a stranger. More prosocial students either shared or donated the money, while the more selfish students kept it for themselves. Using these metrics, Elhert et al. found that having a closer relationship was strongly correlated with having similar levels of prosociality, especially as time progressed, allowing them to conclude that prosocial individuals were clustering together.
Additionally, they provided a primary mechanism for the development of these clusters, arguing that social learning is the most crucial factor in prosocial individuals grouping together. Essentially, rather than saying that students who were more prosocial at the beginning of the year chose to be friends with other people who were also more prosocial, this study argues that individuals mostly adapted their level of prosociality to become more similar to their friends over time. For example, Elhert et al. were able to determine that individuals more closely affiliated with prosocial individuals grew to be more prosocial themselves, as compared to those who were in a less prosocial environment but demonstrated similar levels of prosociality at the start. Conversely, more prosocial individuals in a close network experienced a small drop in prosociality to match the average of their peers. These effects implied that the most crucial factor in creating a beneficial cluster was not individual predisposition, but rather being exposed to an environment that reinforced prosocial behaviors.
Since this study only looked at adolescents within a specific cultural context, it will be important for researchers to explore these conclusions in different groups and cultures to confirm their validity. However, it does provide an important first glance into the existence and mechanism of clustering. More so than any measure of inborn prosociality, these results indicate that the behavior of those around us influences how prosocial we will act. In modeling cooperative behavior we can promote prosocial behavior of those around us.
 Ehlert, A., Kindschi, M., Algesheimer, R., & Rauhut, H. (2020). Human social preferences cluster and spread in the field. Proceedings of the National Academy of Sciences, 202000824.
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