Chapter 10 cont d y sex differences in reproductive strategies apply across species: cultural differences are minimal y males lack reproductive confidence, infanticide/ jealousy, girls. could be out of reproductive pool up to 3 years. once commit to reproducing, out of reproductive pool. Isn t about casual mating, more emotional-relationship: men. ready to reproduce. y females are the choosy sex. Culture or biology: biological issue that could have social implications, wrong to assume that gender differences are sociological when have such core biological basis, consider the kiwi . kiwi bird every time male kiwi ejaculates, produces enough sperm to impregnate every female kiwi on the planet. compare with female kiwi basically gets 1 egg. she is going to be choosy. : guys competing for less females. Chapter 3 y a functional map of the brain: fans experience testosterone surges , einstein s brain. brain wired differently, which gave ability to conceptualize the world.