Wiring the Brain

If we all come with pre-wired traits and with adaptations based on our past experiences, are our decisions ever truly free?  When I give talks demonstrating that we all have innate psychological predispositions – traits that influence our behaviour across our lifetimes – I often get asked what implications this has for free will. If our behaviours are affected in some way by our genes or by the way our brains are wired, doesn’t that mean that we’re really not that free after all? The answer depends, I think, on the kind of free will you’re after and on an understanding of the mechanisms by which we make choices. And let me say at the outset that we do make choices. The idea that neuroscience has somehow done away with free will altogether or proven that it is an illusion is nonsense. All neuroscience has shown is that when you are making decisions, things are happening in your brain. This is, to put it mildly, not a surprise – where else would

GWAS ( genome-wide association studies ) for psychiatric illnesses may be about to become a victim of their own success. The idea behind these studies is that common genetic variation – ancient mutations that segregate in the population – may partly underlie the high heritability of common psychiatric and neurological disorders, such as schizophrenia, autism, epilepsy, ADHD, depression, and so on. The accumulating evidence from over ten years of GWAS strongly supports that idea, with many hundreds of such risk variants now having been identified. The problem is it’s not at all clear what to do with that information. GWAS are a method to carry out a kind of genetic epidemiology, based on a simple premise – if a particular genetic variant at some position in the genome (say an “A” base, as opposed to a “T” at position 236,456 on chromosome 9) – is associated with an increased risk of some condition, then the frequency of the “A” version should be higher in peo