Oxytocin and vasopressin, two hormones that inspire feelings of love and generosity when they flood our brains, bind to neurons by attaching to molecules called receptors, which can come in different forms.

 

The new research, led by psychologist Michel Poulin of the University of Buffalo, suggests that if you have the genes that give you certain versions of those hormone receptors, you’re more likely to be a nice person than if you have the genes for one of the other versions. However, the researchers found that the genes work in concert with a person’s upbringing and life experiences to determine how sociable — or anti-social — he or she becomes.

via Niceness is in Your DNA, Scientists Find | Is Being Nice Genetic? | Nature vs. Nurture | LifesLittleMysteries.com.