Sunday 15 January 2017

Why neurosciences can't tell us much about ... human behaviour

There has been a spate of recent books on the insights of brain science on our behaviour. The main news is that we are probably not as independent from our brains as we think we are when making decisions. In fact, there is now good evidence that our brains decide things before we even start to think about things. If that sounds irrational, so it is indeed. Reasoning is out, impetus is in.

Whilst scientists appear to agree increasingly that our synapses fire before we can think about our options, the jury is out on whether this makes us better or worse when it comes to social behaviour. If neurosciences tell us that our brains make decisions for us and instead of us, do they have a tendency to select one option over another? Are our brains hardwired to be 'social' or 'altruistic' rather than 'egoistic' and 'selfish'?

Some neuroscientists draw on evolutionary biology and psychological experiments to answer this question. One of the more interesting attempts has been Donald Pfaff's book The altruistic brain. He develops a theory about why our brains are more likely to select the more 'altruistic' option in moments of snap decisions, rather than the selfish option.

Pfaff's theory combines evidence from evolutionary biology with recent findings from neuroscience  experiments (basically: people in MRI scanners pressing buttons), but his theory has a wider scope and it is there that it runs into considerable trouble. Here is why.

The holy grail of neurosciences but not much space for moral thinking
MRI scanner in action. Foto: NHS Choices

There may be sound evidence that our brains are designed in such a way as to pre-empt our reasoning. After all, it makes sense to have a brain mechanism to make the right selection from a range of difficult options when we are in immediate danger. The narratives of evolutionary biologists speak to this issue. We may be likely to protect our closest family members 'without much thinking' as this safeguards our genetic prospects.

Pfaff's theory however has a larger scope. He gives an instructive example in his book when talking about the firefighter Steven Siller who, on his day off, hears about the attack on the World Trade Centre, and spontaneously decides to pick up his gear and drive himself down to the centre of the attack to rescue people. Steven lost his life while helping others so Pfaff can justly claim that Steven's actions are undeniably altruistic.

But look more closely and Pfaff's theory of altruistic brain looks a bit more on shaky grounds. Neuroscience experiments say something about the predominance of altruistic or non-selfish behaviour in the moment before our thinking kicks in. That may account for Steven's actions in the moment he hears about the 9/11 attack. But Steven did not stop there. He now faced a long drive to the location of the attack which gave him plenty of opportunity to think hard about what he is doing and why. For this period of time when we contemplate and consider the right course of action, neurosciences can't tell us much. Our reasoning is safely removed from instant brain surges. After all, to assume this separation between the impetus of the brain and our reasoning is the precondition for neuroscientific theories of human behaviour in the first place. Pfaff therefore can't have it both ways. Our reasoning must, at some point, take over.

Claiming that our brains guide us in our behaviour prior to our considered rational thought can only extent to the domain of instant behaviour. Where behaviour is considered, thoughts always trump the predominance of brain matter.

Since Pfaff does not want to accept this, he would need to tell us why the brains' altruistic preferences extend not only to the milliseconds before we make a decision but also to the hours and hours when we mull something over and consider our options (and often revise our behaviour).

Yet, that is not where the difficulties end since Pfaff wants to mould a behaviour moderating mechanism out of his theory. If we knew the brain activity that guides us (prior to rational thinking) to altruistic behaviour, perhaps we can, so he argues, subject criminals to neuroaltering procedures to strengthen their 'good' over their 'bad' behaviour?  Sounds familiar?

Yes, we have been here before. Pfaff walks the path of every other scientist who believes in the ability of his own theory to change this world to the better if only we apply the theory consistently and without much consideration for our own moral compass. Imagine if we could change people's brains, we could make this a better world.

But his thinking is based on a series of fallacious assumptions. The first one is that, if only we could eliminate 'non-altruistic' behaviour we will all live happily ever after. What he fails to understand is that 'good' behaviour only exists because we can point to behaviour that isn't such. Good things happen because we know what bad things look like, and vice versa.

The second grave error he makes is to assume that 'altruistism' is something that we can just point to when we see it (unfortunately, Pfaff also uses the terms 'reciprocal' with 'altruistic' interchangeably which is problematic since not all reciprocal behaviour is altruistic). But altruism is not a fixed entity, it requires interpretation and people often profoundly disagree about what constitutes altruistic behaviour and what does not. In fact it takes a lot of thinking (cue our capacity for rational thought) to determine what is altruistic course of action in a given situation. And. ultimately, we might come to different conclusions and agree to disagree of whether or not something is altruistic. Neurosciences can't help us in this search for intersubjective truth.

There is a fundamental revelation in the Christian doctrine of original sin that reflects this issue of uncertainty. If you look beyond the narrow theological interpretations of the fall of man, one can see that it hints at an irreducable aspect of the human condition. It is the inability to agree and say with certainty what is good or bad (metaphorically also represented in the Tower of Babel and the proliferation of many languages). Neurosciences won't help us to return to a state of innocence. It is up to us, rational human beings, to argue about what is good and what is evil. No MRI scanner can help us in this quest.

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