I was having a discussion with a friend recently about the influence of genetics on mental gifts. I was saying that my grandmother used to track various talents through the family. So and so got the music, someone else got the math, and so on. To my surprise, my friend said that genetics played no part in mental gifts, that there was no such thing as music or math gene. I tried to make it clear that I wasn't saying there was a single gene for either of these, but there were clusters of genetic predispositions that quickened interest and skills, and even attitudes. He maintained that it was all due to early experience and environment. On reflection, it does still seem to me that such gifts run in families, and although environment surely plays a part, it doesn't seem like much of a stretch to say that genetics does, too. If genetics can affect a pancreas or heart, why couldn't it also influence a brain? It interested me, so I've been doing some reading. Today I fin...