It's All Random

Because of Joseph Henrich's (The WEIRDest People in the World) spirited defense of cultural evolution, I have come around to the the possibility that both biological evolution and cultural evolution operate. Prior to this I was thinking of nature-nurture in simplest terms, admitting the idea of epigenetics in theory and reserving some space for free will, but going hard against the idea that what we usually call the environment has much effect except during the time it is being exerted.  You have an effect on your children while they are at home.  It declines progressively once they leave. My view would be that the biological, genetic evolution is the ground floor. It is usually quite flexible and adaptable because that's what  it would have to be for humans to survive.  We have to have a lot of emergency plans hidden in the junk DNA, and whole disks of backup plans for when the well goes dry.  But it still exerts pressure on what happens in our lives even when we pay no attention to it.  Cultural evolution would be the next floor up. It is also flexible but not infinitely flexible. For an excellent example of this, I recommend the story of cassava processing in Section 6.2 at the link. The next story above that is probably randomness. It is also called unshared environment in discussing development, those chance happening that affect your sister but not you, because she has different friends, went on different field trips, and happened to be on the ski lift when it stopped while you were in the lodge drinking cocoa. 

I was explaining this to an old friend who smilingly interrupted to say "It's all random...You think genetics isn't random?" Well, she had me dead to rights there.  If you were conceived 0.4 seconds later you'd be a different person, even 50-50 you'd be a different sex. 

I was going to go on about clan or family action, local action, and individual action, but it seemed pointless after she had summed things up so nicely, so I will just leave them as words of incantation here.  Someplace we get to the idea of free will and whether there is a lot of it or none of it.  With that many filters influencing our behavior at invisible levels, I can see why someone might declare there is no free will just to be free of the burden of figuring it out. Sticklers for reductive materialism will say there is none and everything is caused, but with that much randomness operating in the system there would not have to be more than a trace of free will for there to be enormous (though not fully predictable) effects. But then also, I can see embracing an idea of free will only because that is the how we all act and it hurts our heads to imagine what we would all do if we stopped believing it. That is the world in which we live and move and have our being.