I once watched an interview in which Marlon Brando was asked about the childhood influences that made him an actor. He replied that identical twins separated at birth may both use the same hair tonic, smoke the same brand of cigarettes, vacation on the same beach, and so on. The interviewer, Connie Chung, pretended to snore as if she were sitting through a boring lecture, not realizing that he was answering her question—or, more accurately, explaining why he couldn’t answer it. As long as the heritability of talents and tastes is not zero, none of us has any way of knowing whether a trait has
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