UNDERSTAND SIN

Neurobiologist JACK LEWIS talks to HELEN GLENNY about sin, why we should resist it, and the wacky experiments that test our ability to behave

What are the seven deadly sins, in scientific terms?

They’re seven antisocial impulses, and acting on them tends to break social connections with your community. Christianity says you’ll go to heaven if you avoid these vices, but I argue that you’ll have better relations with other people. That’s important because becoming lonely and isolated from your community has severe negative implications on your physical and mental health.

Can you tell if someone’s sinning by looking at their brain?

The dACC, or dorsal anterior cingulate cortex, has been implicated in a broad spectrum of antisocial behaviours, and the first critical link in the chain came from looking at narcissists. Researchers simulated social exclusion with a virtual game where you’re passing a ball with two friends who then start passing the ball exclusively between themselves, so you feel that horrible feeling of being left out. Activity in the dACC was greater in narcissists experiencing that social pain than in non-narcissists.

Then another study showed that the degree of someone’s narcissism impacted the desire to take revenge in that sort of situation, but only if that social rejection led to an increase in dACC activation.

When I went on and looked at other sins, this area kept cropping up. It lights up when people are feeling physical pain, social pain or processing conflict.

Which other sins caused the dACC to activate?

It cropped up in envy, wrath, lust and the neuroeconomics of greed. Across hundreds of financial exchange experiments, whenever your slice of the pie is smaller than the other person’s, the dACC lights up. There’s also an amazing bunch of experiments about wrath. Psychologists wire up two people so one can electrocute the other, then the person who got zapped can zap the other one back. But everyone believes the electric shock they received was more painful than the one they inflicted, so the participants keep cranking up the intensity. The degree to which the participant cranked up the electric shock was proportional to the degree of activation in the dACC. That’s another suggestion that this brain area could explain, or even be the root cause of the urge to inflict antisocial behaviour on someone.

Can we turn down activity in the dACC to help us avoid sinning?

Researchers have looked at Buddhist monks doing an experiment where there’s a pot of money, and one person can decide how to split it. If the other person isn’t happy about how much they’re offered, they can reject the offer and no one gets any money. If someone offers 30 per cent, taking 70 per cent for themselves, most people turn it down because they’re resentful that the person has proposed such an unequal split. But Buddhist monks accept that deal, and the neural correlates of emotional distress aren’t there.

What can neuroscience tell us about sin?

When people do things they shouldn’t, it’s usually caused by emotional suffering. The best example to support this idea is that the intensity of social pain experienced by narcissists is mirrored in the strength of their dACC activation, which is in turn proportional to the extent of the punishment inflicted on whoever caused them to suffer feelings of rejection in the first place.

Feeling connected to your community is essential to your health, and if you want everyone to stay connected, you need to provide as much help as possible to rein in these antisocial tendencies.