In species that do not use copulatory thrusting, especially insects, penises evolve more obvious tactile stimulators: nubs, spikes, ridges, curls, barbs, hooks, and flagella. Male insects often try to push each other off during copulation, so copulatory thrusting would risk disengagement. Better to lock the genitals…
By primate standards, humans look strange, even after we step out of our sport utility vehicles. Compared with other apes, we have less hair on our bodies, more on our heads, whiter eyes, longer noses, fuller lips, more expressive faces, and more dextrous hands. In most species, sexual ornaments like long head hair…
My interest is in the psychological adaptations that are uniquely human, the 10 percent or so of the brain's capacities that are not shared with other apes. This is where we find puzzling abilities like creative intelligence and complex language that show these great individual differences, these ridiculously high…
The healthy brain theory suggests that our brains are different from those of other apes not because extrava- gantly large brains helped us to survive or to raise offspring, but because such brains are simply better advertisements of how good our genes are. The more complicated the brain, the easier it is to mess up…
The worlds of academia, high fashion, religion, and modern art produce sublime wonders, and sometimes monstrous absurdities. They can afford such creative freedom because their systems of self-regulation and self-perpetuation are insulated from the mun- dane pragmatics of the outside world. Their autonomy endows them…
Even if the survivalist theory could take us from the world of natural history to our capacities for invention, commerce, and knowledge, it cannot account for the more ornamental and enjoyable aspects of human culture: art, music, sports, drama, comedy, and political ideals. At this point the survivalist theories…
Most of the genetic differences between races are trivial. And yet others, those physical differences between a Japanese individual and a Finn, a Masai, and an Inuit, are striking. We have the interesting situation, then, that the overall differences in gene sequences between peoples are minor, yet those same groups…
Sexual selection doesn’t end with the sex act itself: males can continue to compete even after mating. In many species, females mate with more than one male over a short period of time. After a male inseminates a female, how can he prevent other males from fertilizing her and stealing his paternity? This postmating…
Likewise, the manner in which sexual selection capriciously seizes upon preexisting perceptual biases fits with the fact that apes are by nature naturally "curious, playful, easily bored, and appreciative of simulation." Miller suggests that to keep a husbanc around long enough to help in raising children, women would…