Pinker is quoting what is taught in med school: personality is 40% genetics, 40% familial influence in growing up and 20% personal conclusions from experience when independent of family. In his latest book The Blank Slate Pinker suggests the influences are about 40% genetic, about 50% peers, and maybe 10% family. Surprisingly low on the family side?-> As far as chemicals and illnesses messing with brain function, I thought we were discussing normal people, defined as not with a disease. Obviously you make a good point. I'm sure I am more normal than you are. :-)) We certainly may have unrecognized quirks, and I view free will as within those limts for that person.-How many whiskies do I have to have before I loose my free will? Just enough to pass out?-I have read that about half of our non-coding DNA appears viral in origin? Is this correct?