Tag: chris ryan

TED talk notes: Chris Ryan on why humans are promiscuous but gorillas are not

Every week, I share my notes from great TED talks. Here’s the complete list (pardon the load time, it’s a long page).

Here are two talks from Chris Ryan about sex. I took notes on both, but the notes were smushed together like a chicken pot pie so it’s not clear what set of notes are from which talk.

Chris Ryan on sex

  • humans are more related to chimps and bonobos than one elephant species to another
  • the standard narrative: men trade resources for sex, a woman’s fidelity, and childcare
    • this has been the narrative since Darwin’s time
    • but it sets up male vs female as competing, oppositional genders
  • the standard narrative is wrong; instead, it’s about sperm competition INSIDE the woman’s reproductive tract, within an ovulatory cycle
  • this is fierce egalitarianism — everything is shared, which is the smartest way to survive in a foraging society
  • monogamous primates (gorillas, gibbons) have small testicles and penii
  • …while promiscuous primates (humans, chimps) have larger testicles and penii
    • the human female is rare in being available for sex through her ENTIRE menstrual cycle
    • humans have testicles in a sac outside of the body to keep them cool so they’re available for sex at any time
    • A chimp’s swollen ass signals she’s available for sex with different males; this confused Darwin because he expected a pair-bonding relationship
  • our sex act to birth ratio is 1000 to 1, whereas for gorillas (monogamous) is 10 to 1
    • most mammals don’t have sex unless there’s a good chance of fertilizing
    • why do we have so much sex? we use sex to develop complex social networks — common in intelligent social species like dolphins and chimps
    • sex is like vegetarianism — it’s healthy, it’s social
  • examples
    • in a SW China village, women and men are sexually autonomous, both have many sexual partners; when woman has a child, it’s cared for by her, her sisters and her brothers; the biological father is a non-issue
    • in a S American (?) village, children are viewed as product of many men’s sperm, so if you want a strong, smart, and funny child, you have sex with those types of partners; the partners all recognize the role they played in fathering the child

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Here’s the full list of TED notes!