Researchers at the UCSB Center for Evolutionary Psychology presented new findings regarding the psychological motivators behind human cooperation and justice in an article published last Wednesday in the open-access, peer-reviewed scientific journal PLoS ONE.

The study focuses on humans’ willingness to cooperate with new people, their interest in the reputations of others based on how they treat people and their desire to punish those who have committed acts perceived as selfish or wrong. The article is based on the results of a study in which over 200 participants engaged in a series of pre-arranged social interactions aimed to simulate real-world situations.

According to the article’s lead author, Max Krasnow, a UCSB postdoctoral researcher in the department of psychology, people tend to feel helpful toward unfamiliar people who have performed kind deeds and angry and confrontational toward those who have been unjust.

“Imagine that, while grocery shopping, you see someone help a wheelchair-bound person he or she doesn’t know get her bags across the parking lot to her car,” Krasnow said in a press release. “For many people, witnessing the action would elicit feelings of kindness toward the helper. Equally, if people see someone driven off the road by a reckless driver, they might become angry enough to pursue and even confront the driver.”

Krasnow said evolutionary scientists seek to explain the human impulses behind aiding the kind and penalizing the insensitive, traits which pose a potential risk to those who demonstrate them.

One theory on the issue focuses on the importance of these social impulses in the smaller human populations of centuries past, a context where each meeting had the potential to grow into a more long-term relationship. As a result, humans were more attuned to people who were cooperative and likely to produce a relationship with mutual benefits.

The second theory postulates that our ancestors lived in constantly competing populations. Groups with better internal cooperation gained an upper hand over other populations, making it important for individuals to identify those who exhibited kind, cooperative personalities in order to incorporate them into the larger group culture.

According to Krasnow, the study was designed to examine which criteria must be present in order for test subjects to cooperate with others whom they are unfamiliar.

“We wanted to know exactly what kinds of information people actually use in deciding who to trust — that is, who to cooperate with, and who to avoid,” Krasnow said in a press release. “If our minds are designed to seek out the benefits of cooperative relationships with others, then participants should have preferred to trust those likely to cooperate with them in particular. On the other hand, if our reputational psychology is designed to support group-wide cohesion and cooperation, the participants should have resisted cooperating with those who defected on other group members.”

Anthropology professor John Tooby, co-director of UCSB’s Center for Evolutionary Psychology, said the findings supported the first theory of individual cooperation and not the second on group cooperation.

Further testing on the reasoning behind the continual evolvement of cheating showed additional support for the first theory.

Krasnow said the findings indicate a collective, underlying sincerity behind these actions.

“The current research findings suggest that the human readiness to cooperate, our selectivity in who we cooperate with and our tendency to respond negatively when we are cheated from an efficient package to forge and maintain strongly cooperative relationships,” Krasnow said in a press release. “The human tendencies to care about how a person treats others and to protest bad treatment are not simply a thin veneer of cultural norms atop a cold and calculating core. Rather, they represent fundamental features of a universal human social nature.”