http://www.sciencedaily.com/releases/2011/11/111115103510.htm

ScienceDaily (Nov. 15, 2011) — There's definitely something to be said for first impressions. New research from the University of California, Berkeley, suggests it can take just 20 seconds to detect whether a stranger is genetically inclined to being trustworthy, kind or compassionate.

The findings reinforce that healthy humans are wired to recognize strangers who may help them out in a tough situation. They also pave the way for genetic therapies for people who are not innately sympathetic, researchers said.

"It's remarkable that complete strangers could pick up on who's trustworthy, kind or compassionate in 20 seconds when all they saw was a person sitting in a chair listening to someone talk," said Aleksandr Kogan, lead author of the study and a postdoctoral student at the University of Toronto at Mississauga.

Two dozen couples participated in the UC Berkeley study, and each provided DNA samples. Researchers then documented the couples as they talked about times when they had suffered. Video was recorded only of the partners as they took turns listening.