Whether human or hyena, there' s safety in numbers

In other words, there's safety in numbers, according to a new study by two Michigan State University scholars. Their research provides the first evidence that people's visual biases change when surrounded by members of their own group.

"Having one's group or posse around actually changes the perceived seriousness of the threat," said Joseph Cesario, lead author on the study and assistant professor of psychology. "In that situation, they don't see the threat quite so closely because they have their people around to support them in responding to the threat.'"

Funded by the National Science Foundation, the study appears online in the journal Social Psychological and Personality Science.

The study was inspired by MSU zoologist Kay Holekamp's research with wild hyenas in Kenya. Holekamp and her team played recordings of hyenas from other parts of Africa and found the hyenas listening to the voices were more likely to approach the source of the sound when they were in groups and more likely to flee when they were alone.

The research by Cesario and Carlos Navarrete, associate professor of psychology, was similar, only it dealt with humans and perceived distance of potential threats. In two separate studies of more than 300 participants, the researchers showed that people who are alone judge threats as much closer than when they are in a group.

Like most social species, hyenas and humans have developed adaptations over time to better deal with predatory threats.

"This is about evolutionarily significant threats, such as members of a different group coming to steal resources or attack you," Cesario said. "The cost of not responding soon enough to a threat like that could be death or serious injury. So seeing that threat as closer allows you to respond with enough time to spare. What our work shows is that having your group or coalition around you makes that kind of early responding less necessary."

The study dealt with racial bias and group threats. The participants, who were white, were assessed on how negative they were toward blacks and then asked to judge the distance to a black community, both when the participants were alone and as part of a group.

Cesario said the perceived threat can take many forms -- be it from other races, communities or even students from another university, as one nonrelated study showed.

"So this line of research has little to do with the makeup of the group -- whether it's members of another race or students from another college -- but more to do with the question of, 'Are you with me or not?'"