Dr. Small used a study out of the Brain & Mind Research Institute in Sydney, Australia. The authors injected 69 male participants with either oxytocin or a placebo. Subjects were then shown faces with "happy, angry, or neutral" expressions. When the subjects returned the next day to review the faces, the ones that had received the oxytocin shot were more likely to remember the "happy" faces then the angry ones. From this - just this - the authors extrapolated to say:
"the administration of oxytocin to male humans enhances the encoding of positive social information to make it more memorable. Results suggest that oxytocin could enhance social approach, intimacy, and bonding in male humans by strengthening encoding to make the recall of positive social information more likely."I think the authors are pushing it. However, they don't go as far as Dr. Small. She says that since oxytocin is heavily involved with childbirth and lactation, women in cultures with "no birth control" are usually "awash" with it. This, she claims, is the reason that women have "traditionally" been "the keepers of positive social interactions." Because women in Western societies use birth control and thus aren't "under the influence" of as much oxytocin, they're more likely to "never forget an angry face" or "hold a grudge." For Dr. Small, these are synonymous with "manly."
So there are some problems with this. First, cultures with no chemical birth control usually practice other methods of reducing births. Granted, one of these is prolonged nursing, but others include taboos on sex and (this is controversial) polygyny. Second, I agree that hormones and brain chemistry are physical processes mostly beyond our control. However, the way one expresses the effects of these chemical surges are culturally and socially shaped. When your brain starts sending you "hungry" signals, you're either going to go to the fridge or grab your bow and arrow - depending on your enculturation into a given system. Third, Dr. Small's claims are completely anecdotal. Does she have evidence that women on chemical birth control are generally angrier, less emotional, more "manly?"
My hormones are part of my behavior, yes. But they don't define it.