Human pro-sociality towards non-kin is ubiquitous and almost unique in the animal kingdom. It remains poorly understood, though a proliferation of theories has arisen to explain it. We present evidence from survey data and from laboratory treatment of experimental subjects that is consistent with a set of theories based on group level selection of cultural norms favoring pro-sociality. In particular, increases in competition increase trust levels of individuals who: i) work in firms facing more competition, ii) live in states where competition increases, iii) move to more competitive industries and iv) are placed into groups facing higher competition in a laboratory experiment. The findings provide support for cultural group selection as a contributor to human pro-sociality. 

"The Origins of Human Pro-Sociality: Cultural Group Selection in the Workplace and the Laboratory", by Patrick Francois, Thomas Fujiwara, and Tanguy van Ypersele. Forthcoming in Science Advances.