The neuroscience of morality

Morality’s a pretty slippery subject. The endless collective hours mankind has spent strenuously locked in full chin-on-fist frown-face mode debating the great ethical headaches have led to few, if any, irrefutable moral epiphanies. As such, it’s made life a pretty exhausting series of moral dilemmas, whether you’re putting on foreign accents to avoid charity fundraisers, swapping your child for some Toblerone, or strapping fireworks to cats and racing them for YouTube gold.

However, advancements in neuroscience are beginning to slowly illuminate the mysterious realm of the brain, the structure in which many of us place large accounts of our personality and very humanity. What can Neuroscience teach us about morality? Can it be here that we can finally discover some groundwork for morality upon which to finally base our lives?

Discoveries in the workings of the brain certainly seem to provide some insight. One key molecule present in promoting what can be seen as ‘moral behaviour’ is oxytocin. Oxytocin is a hormone that plays a huge role in mammalian behaviour, particularly those of bonding and areas which facilitate sexual reproduction. Our ability to care for others is directly linked to our ability to secrete oxytocin, inability to do so often observed in individuals who cannot feel empathy, in cases such as those of psychopathy. This suggests it may indeed be a crucial factor of our morality, as we can observe in its effect on other mammals.

One such example may be seen in comparing the effects of oxytocin in the comparable behaviours of prairie voles and montane voles. Prairie voles have a fairly special mating habit in that, having mated, male and female voles will continue contact with each others for the rest of their lives (“awwww how sweet”), unlike montane voles, which do not continue contact after mating. Leading neuroscientist Sue Carter has evidence to suggest this may be due to differences in densities of oxytocin receptors (as well as receptors of vasopressin, a similar hormone) in specific areas of the two species’ brains. She found that, on blocking the oxytocin receptors in prairie voles brains, she could drastically change their behaviour in mating.

The hormone has also been linked to further bonding beyond the functions of mating, such as the cooperative behaviour of baboons, chimps, and wolves forming packs. In each of these situations there has been an advantage to this behaviour of attachment. Wolves can more easily catch bigger game, such as caribou or moose, when hunting in packs, as can they pose a greater threat to ward off other predators, such as grizzly bears, who may steal their kills. The monogamous behaviour of prairie voles has been linked to the greater threat of predators, such as kestrels, in areas they populate. Male prairie voles, in staying with their partner rather than going on their merry way, will guard the nest inhabited by the female and offspring, aiding the arguably more vulnerable survival than those of montane voles.

Ok, so we’re not prairie voles, but, being mammals, this provides more insight than you’d imagine. It helps shed light on, for one thing, why we mate for life, and see this as a moral decision. The specific location of oxytocin receptors in our brains may be the key to this aspect of our behaviour, although the reasons we evolved as such are pretty open to interpretation.

So if our general altruism can be linked to oxytocin and, specifically, the location of such receptors in our brains, what can we say about more complex moral decisions? Staying with your partner and caring for your family are fairly primitive. What about my reasoning in other areas? What does neuroscience say to our ability to reason questions such as those of consequentialism? You know, problems like “a truck containing 10 people is hurtling out of control towards a cliff edge, and the only way to stop it is to push a fat bloke in front of it, killing him, but saving the 10″. What can we say about that from observing the brain?

Molly Crockett, Zurich based neuroscientist, has discovered that our answer to such a question may stem from how much serotonin we have in our bodies at any given time. Serotonin is a neurotransmitter (a chemical that transmits signals between neurons and cells across synapses in our brains) that has often been thought of as one of the ‘feel-good’ chemicals. Drugs such as citalopram, and other anti-depressants, attempt to combat anxiety and depressions by raising our serotonin levels. So what can it have to do with our morality?

Crockett has conducted numerous experiments to test this. In one, she asked subjects to play a game from economics called the ultimatum game, in which two people must try and settle a financial dispute given the following criteria: they both must divide a sum of money given to them, but only one, the proposer, is allowed to decide the how much each one gets, the other, the responder, can only agree to the terms or not. If the responder agrees, no matter how unfair the proposal may be, they both keep the money under the agreed terms. If the responder disagrees, neither keeps the money.

Divisors of the game did not think it would have very interesting results, predicting that, no matter how unfair the split, responders would always take the money – a tiny share of something is better than nothing, anyone can see that right? In fact, humans are much more spiteful than we’d like to think. If people think a proposer is being unfair in their terms, we’d rather see them walk away empty handed than receive more than us, even if we must sacrifice our share too.

Crockett’s experiments tested the effect of increased or depleted serotonin levels on the responders, and found that raised serotonin levels led them to be much more likely to accept even the most unfair offer. People seemed to care less about the unjust division of money, more content with taking at least a small share, and indifferent to the unjust proposer receiving the lion’s share.

She further discovered that the effects of serotonin were much greater on individuals who already considered themselves characteristically empathetic. If someone considered themselves a kind, unaggressive individual, it seems a determining factor in their behaviour may be their comparatively heightened sensitivity to serotonin.

That does indeed lay some groundwork, as it seems to imply that much of our ability for altruism is in some ways innate, but also affected by the presence of serotonin in our bodies. The implications of this are great an deeply interesting, such as whether our unkind actions may simply be due to a combination of lifestyle choices (such as our particular diet and exercise, etc) unrelated to moral decisions, but have left us relatively depleted in serotonin. Can there ever be an intrinsic moral code, if our decisions are regulated by such a variable as the circumstantial presence of certain drugs in our bodies? If we become more utilitarian the less serotonin we have in us, how can we ever agree on such codes if our bodies fluctuate so constantly? How much do our decisions in life depend on the presence of this chemical? Can we ever call someone unkind, should we rather say “aye-up, that chap could do with some serotonin”? Is it right to intervene, and provide serotonin for those who are otherwise quite resentful people?

Many people responded unkindly to Crockett’s discoveries. In an interview with Nigel Warburton, she put this down to the unease of some people, reluctant to hear that their morality was governed by chemicals in the brain. If our actions are so influenced by drugs and chemicals, it is difficult to humanise our actions and teach people shame in their mistakes or pride in their successes. However, it is difficult to think of it coming from anywhere else isn’t it? Just because these finding illuminate the machinations of the brain, these do not change how we should regard our actions. Serotonin may make us feel good about our good actions, or put us in a less aggressive frame of mind, but we’ve always known we feel good for our good deeds, we now just know a little more about why that is. Nothing’s changed, really.

Patricia Churchland, a leading neuroscientist, has said that while discoveries are being made all the time in how we work, she does not believe there will ever be a map of the brain so complete that we will find neurological evidence as to our determinations of, say, a ‘just war’. The big questions, then, are still up for grabs. Pumped up on serotonin we may not push fatty in front of the truck, if a bit depleted we might be slightly more utilitarian. We may love one another based on our response to oxytocin and similar molecules, such as vasopressin. These do not rob us of our humanity, they just help explain it.

For the most part, it seems the big questions have not been even nearly answered. But, as we develop a better and better understanding of our motivation behind morality, so too may we adjust our moral stances, and be less afraid of the cold, robotic force of science shaking hands with the, err, fluffy bear of morality. Or something.

About these ads

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s