I am a complete layman in this but have been wondering about what makes us us. While I think I am right in saying the brain works on electrical and chemical impulses there also appears to be what I would call rom and ram (from computing) or instinct and learnt behaviour, how much is genetic pre-programming. I ask this from observations about birds which seem at least to me about halfway between higher and lower animals. The thing with birds is that you can tell the species, generally, just from looking at the nest. Nestbuilding as far as I can see is not taught yet is extremely complicated in some species. Birds of the same species will build the same nests using the same materials, you cannot tell the difference between a novice and one that has built previously, a ground nesting bird will build on the ground etc. This to me suggests that how to build, what materials to use and where to build are all genetically pre-programmed, whereas finding food is taught, I have seen this. The higher up the scale you go the less seems to be pre-programmed and the more taught. I wonder though how much of our makeup is genetic and how much learnt. Children brought up much the same can be completely different to the extent that upbringing cannot explain, there are characteristics that seem to be inherited.