Trust, Love, and Crime

So it should seem fairly obvious that people tend not to commit crimes that hurt people they trust. Likewise, people trust others who have a history of being non-threatening. So trust plays a big part in determining when and whether crime occurs. But how does trust develop?

In this month's issue of Scientific American, Paul Zak presents some of the research he's done exploring this issue. As a neuroeconomist, he relies primarily on two research tools: economic games and brain scans. Okay, yes, predictable, but it's how you use the tools that counts. Zak uses what's called "The Trust Game," which requires two subjects. First, the researcher gives both subjects $10 (separately - they keep them anonymous). The first subject then has the chance to give some of this money to the second subject, again anonymously. The second subject receives triple the amount that the first subject gave, with the option then of returning as much as he or she wants. Both subjects know the rules of the game and the risks involved, i.e., that there's no guaranteed return on an investment. A measure of trust can be obtained by looking at how much either subject chooses to give or return.

So with a way to gauge levels of trust, Zak looked into the effects of a naturally-occurring chemical - Oxytocin. Oxytocin's one of those small chemicals that finds a way of getting anywhere in the body. So while it's primarily known for its role in inducing labor, it also gets into the brain, where one of its roles is to initiate maternal bonding. In fact, oxytocin has been pegged as the main chemical that is responsible for women's feelings of love - the long-lasting, devotional kind. (Though it occurs in both sexes, the corresponding chemical in men is vasopressin, which normally regulates water balance. I just found out, though, that, evolutionarily, they're very close.)

If a subject is given a nasal spritz of oxytocin, Zak found that they'd then be more willing to give or return more than control subjects, suggesting that oxytocin has the effect of inspiring trust. Not entirely unexpected. But one interesting, and unexpected, finding in this study was that there were a small number of subjects who had high levels of oxytocin, but who returned absolutely nothing repeatedly when they were in that role.

So what gives? The author speculates that these subjects may have a congenital insensitivity to oxytocin. No matter how high their levels may be, the chemical has no effect on them. What this means is that these people seem to be largely insensitive to others' considerations, and be unable to trust them. This may actually be a predisposing factor to psychopathy, which is characterized partially by the same factors. So does this mean that we may have found a "cure" for psychopathy? Possibly, if some day researchers are able to genetically engineer the appropriate receptors. But right now it's just an interesting avenue of research.