Oxytocin

Paul Zak is renowned among his colleagues for two things he does disconcertingly soon after meeting people. The first is hugging: seeing me approach, he springs to his feet, and enfolds me in his arms. The second is talking them into having needles stuck into their arms to draw blood. I escape our encounter unpunctured, but plenty don’t, willingly, of course. Zak’s work has involved extracting blood from, amongst others, a couple on their wedding day, people who have been dancing, and a group in Papua New Guinea preparing to perform traditional rituals.

Having dipped into his book, The Moral Molecule, I know that what drives Zak’s hunger for blood is his interest in oxytocin. Long known as a female reproductive hormone, oxytocin emerges from Zak’s research as something much more. Being treated decently, he says, causes people’s oxytocin levels to rise, prompting them to behave more decently, while experimental subjects given an artificial oxytocin boost behave more generously and trustingly. Describing the chemical as the ‘moral molecule that keeps society together’, Zak offers nothing less than a vast explanation of whole swathes of philosophical questions. The subtitle of the book, The New Science of What Makes Us Good or Evil, gives a sense of this.

The aforementioned wedding took place at a house in England, where Zak set up the equipment needed to collect blood. He took samples, before and after the ceremony, from the bride and groom, and various guests, then transferred his spoils to his laboratory. There, he discovered the results he’d been expecting: the ceremony caused oxytocin to spike. And it did so ‘in direct proportion to the likely intensity of emotional engagement in the event’.

The bride recorded the highest increase, followed by close family members, then less closely involved friends. Mapping the wedding’s oxytocin levels gave rise, in Zak’s words, to an amazing human ‘solar system’ with the bride as the sun, the hormone finely calibrated to the emotional warmth each guest felt.

Zak’s interest in oxytocin was fuelled by experiments involving the Trust Game. Participant A is invited to lend some money to a stranger, Participant B. They’re told that any money A sends will triple in value, whereupon B can return some as a thank-you. According to traditional models, the game should break down before it begins. B, acting selfishly, has no reason to give any money back – and, knowing this, A shouldn’t send any in the first place. However, as in previous research with this tried and tested set up, the vast majority of A-people send money, while an even larger percentage of B-people return some. Zak’s analysis of the oxytocin in participants’ bloodstreams reveals that by sending money to B, person A is giving a sign of trust – and for person B, being on the receiving end causes oxytocin levels to increase, motivating more generous behaviour in return.

The possible implications are intriguing. Evolution has given us oxytocin, a biological mechanism that lets us be instinctively trusting and kind – or ‘moral’. Mixing science and morality prompts suspicion, however. Just because something is ‘natural’ doesn’t mean it’s ‘right’, and efforts to derive moral codes from science rarely end well. Moreover, it’s unclear what Zak means when he says oxytocin, or the lack of it, ‘makes’ us good or evil. Still, none of this undermines the pragmatic aspect of Zak’s work. If oxytocin is the mechanism through which moral action takes place, then by manipulating oxytocin, we might boost levels of trust, generosity, and ultimately happiness.

On the other hand, what’s to stop car dealers, say, pumping oxytocin into showrooms? Zak waves the matter away: it’s incredibly hard to get enough oxytocin into the bloodstream. Sure, oxytocin can be stimulated in subtle ways to serve other people’s agendas, ‘but they’re already doing that. Why do you think they have babies in adverts? To make you feel good, by provoking the release of oxytocin.’ Meanwhile, he says, we should all do at least eight hugs a day, massage and even watch soppy movies – he’s done the tests. Interaction on social media seems to lead to oxytocin spikes, undermining the argument that it’s killing real human interaction; hormonally, it appears, the body processes it as real interaction.