The way we behave when threatened sometimes goes against conventional wisdom: we soften up. Andrew White, a PhD student at Arizona State University, and his colleagues analyzed data from 54 nations and found that the more a nation spent on its military (presumably a good index of perceived threat), the higher its people scored on self-report measures of how agreeable they were to others.
This trend, published in the October 2012 issue of Interpersonal Relations and Group Processes, held all the way down to the individual level: People who believe the world is a dangerous place reported being more agreeable than those who don’t.
“It is a very nice contribution to the literature on prosocial behavior,” says Paul A. M. van Lange, a social psychology professor at Vrije University Amsterdam, who was not part of this study. “Many people think in terms of mental shortcuts or heuristics: aggression leads to aggression and niceness leads to niceness. But to understand human thought and behavior, one should go deeper.”
Read more at Scientific American