BUFFALO, NY -- New research from the University at Buffalo could explain why people are jerks -- and why some are so sweet.

Michel Poulin, Ph.D., assistant professor of psychology at UB, is the principal author of the study "The Neurogenics of Niceness," published in this month in Psychological Science, a journal of the Association for Psychological Science.

His research suggests mom and dad's DNA contributions predispose their children to certain moods.

He and his team observed subjects with versions of receptor genes for two hormones that scientists associate with niceness. Earlier laboratory studies have linked the hormones oxytocin and vasopressin to the way we treat one another, says Poulin. His research applied subjects' behavior to these findings on a larger scale.

"The fact that the genes predicted behavior only in combination with people's experiences and feelings about the world isn't surprising," says Poulin, "because most connections between DNA and social behavior are complex."

So to blame genetics entirely for behavior -- good or bad -- won't cut it.

"If one of your neighbors seems [like a] really generous, caring, or civic-minded kind of person, while another seems more selfish, tight-fisted and not as interested in pitching in, their DNA may help explain why one of them is nicer than the other," he says.

Poulin stops short of saying he found the "nice" gene.

He does add, however, "We have found a gene that makes a contribution. What I find so interesting is the fact that it only makes a contribution in the presence of certain feelings people have about the world around them."

Want a deeper dive into Poulin's research and method? Click to head to Psychological Science.

Earlier on HuffPost:

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