Benoit Hardy-Vallee gives a deep and detailed analysis of research exploring how oxytocin influences economic decisions.
His post on Natural Rationality focuses on a paper presented by Paul Zak and others at a recent Economic Science Association meeting. The bottom line, he says, is "generosity 'runs' on empathy."
Benoit-Vallee provides details from the paper showing the statistical differences in behavior; if you like to dig into such research, his post is a good place to start. In general, his new blog is devoted to that wiggly interaction of hypothalamus and prefrontal cortex, as expressed in economic decisions.
You can click through from his blog to the paper itself.
See also "Toward a Non-Autistic Economy."