Evolution, they think, can construct only stupid instincts and fixed action patterns: a sex drive, an aggression urge, a territorial imperative, hens sitting on eggs and ducklings following hulks. Human behavior is too ______ and ______ to be a product of evolution, they think; it must come from somewhere else—from, say, “culture.” But if evolution equipped us not with irresistible urges and rigid reflexes but with a neural computer, everything changes.
