When I read in the news shallow pop psychology takes on the heritability of specific traits, like conservative voting, homosexuality, and alcoholism, I am annoyed by the scientific ignorance of newspaper reporters.
I have planned, for a year, to put some time aside to write a magnum blopus on the subject, but finally realized it's better just to post something on the subject, and forget about letting the "best" be the enemy of the "good enough". Tempus fugit.
There is no doubt that personality traits are inherited. Every grandma, dog breeder, and parent knows this. And every family knows this: Bill is a true "Smith." Sally is a real "Jones." Ally is a real blend. Ted is a clone of Grandpa.
They call this general field of study "behavioral genetics," but it is actually about personality genetics and the heritability of "temperament." When you see identical twins, separated at birth via adoption, smoking the same brand of cigarettes, having the same IQ, and driving similar cars on opposite coasts, you can see it dramatically, but the fact is that the underpinnings - the foundations of personality, are surely inherited.
But they are not inherited like eye color. It's complicated.
But what is done with those foundations is what is most interesting. Free will does exist.
