The self: genes, environment, chance, and ... free will
Steven Pinker's "My Genome, My Self" is a valuable reminder that
as well as a useful summary of the kinds of observations that lead to those conclusions, and wise advice for those who may (or may not) want to know more about their own genes. As Pinker points out, who one is is influenced by genes, but influenced as well by personal experiences, and by chance, so genes are relevant to the question of who one is but not the answer to that question.
In fact, there probably isn't AN answer. Humans may indeed be, as Pinker suggests, "prone to essentialism - the intuition that living things house some hidden substance that gives them their form and determines their powers." But the more one looks into the matter, the less this seems to be the case. Being alive is not a matter of an elan vital but rather of having particular mixes of influences and properties, of being a complex assembly of diverse non-living things. Similarly, being onself is increasingly looking like ... having a mix of influences and properties, being a complex assembly of diverse living things (each themselves an assembly of diverse non-living things).
I was glad to see Pinker include genes, environment, AND chance in his catalogue of influences (cf From Genomes to Dreams) but also struck by his off-handed dismissal of a fourth influence that I would include: "free will, whatever that means." Given chance and some architectural characteristics of human brains, there are perfectly good ways to give a meaningful account of free will (cf Variability in Behavior and the Nervous System and Evolution/Science: Inverting the Relationship between Randomness and Meaning). And no reason not to include it as among the things that contribute to our ability to "defy our genotypes." Indeed, I would have thought that someone who is "more libertarian than authoritarian" would have been particularly inclined to include it. Regardless, I think its important to encourage people to, as William James put it, "believe in free will" so as to make it a greater part of all of our lives.