The Mating Mind Ch. 6 Courtship in the Pleistocene

1. Kateri Broussard Nick Casias Chris Conger Elissa Vaidman The Mating MindCh. 6 Courtship in the Pleistocene By: Geoffrey Miller

2. Sexual Selection in Primates The distribution of food determines the distribution of males and females, and in so it determines the type of sexual relationships the species engage in. • If food is dispersed so that females forage alone, then the males also disperse and pair up with the single females, creating monogamous relations. -this pattern is seen in gibbons, some lemurs, and some African and South American monkeys.

3. Sexual Selection in Primates • When food is dispersed in large patches, several females will form small groups. A single male is able to control and protect these small groups of females, and doing so gives rise to polygyny - this creates sexual selection for male size, strength, and aggressiveness. -this style is common in hamadryas baboons, colobus monkeys, some langurs, and gorillas.

4. Sexual Selection in Primates • When food is dispersed in even larger patches, the males then also form coalitions, creating a multi-male, multi-female group -this is seen in some baboons, macaques, ring-tailed lemurs, howler monkeys, and chimpanzees -the sexual selection in these groups then is based more on the “strongest swimming sperm,” and in response to this, “male chimps have large testicles, copious ejaculates, and high sperm counts.”

5. Sexual Selection in Primates • Chimpanzees and Bonobos (who are our closest relatives) live in multi male, multi-female groups in which sexual choice is complicated: both sexes compete; both sexes have dominance hierarchies; and both sexes form alliances. • Sexual relationships develop over weeks and years rather than minutes. • Our ancestors probably lived in these same social and sexual conditions.

6. Pleistocene Mating • Lifelong monogamy was virtually unknown • More common was serial monogamy -females wanted to mate with males of higher fitness, and males wanted to mate with as many females as possible

7. Pleistocene Flirting Fewer economic incentives to stay together Fewer distracting entertainments to keep interest More prevalent temptations and opportunities, with very little reason to indulge. Modern Dating We pay people to entertain our dates. We use money to keep the mate’s interest. Due to economic incentives, there is more of a benefit to stay in lifelong commitments Pleistocene flirting Versus Modern Dating

8. Were Fathers Important? • Females had the ability to care for young with little help from the fathers because they had help from other women in their group. • Males were also not needed for protection because females gained even better protection from their closely formed groups. -females were also only 10% shorter than the males • Males were even seen as a burden: eat more than they provide, and demand more care than they may actually give to the child.

9. Combining Courtship and Parenting • Courtship during most of human evolution occurred between adults who already had children. -since children were with mother during courtship period, motherly duties had to become fitness indicators. -children also then must have influenced sexual selection since mothers would have to adhere to children’s preferences.

10. Combining Courtship and Parenting • Through this argument—that children’s preferences indirectly shaped the evolution of adult male humans—a belief has emerged that “paternal effort may actually have evolved through sexual choice as courtship effort. Men attracted women by pleasing their kids.” - refuting this argument is that men in every culture are significantly more likely to beat and kill their step-children than their biological children.

11. Sexual Selection: The Possibilities • Highest-fitness male wants highest-fitness female. And lower-fitness individuals will have to settle for lower-fitness mates. (but fitness matching causes an evolution of fitness indicators such as sexual ornaments and courtships display. We use these indicators as a sign of fitness, but we are unable to assess whether the person with “good” fitness indicators is actually the highest-fitness mate)

12. How Did Our Ancestors Meet? • Ancestors traveled between “bands” and interaction between different bands were very quick . -therefore, quick decisions about sexual opportunity in the bands had to be made; probably based on physical appearance, bodily ornamentation, apparent social status, and public display behavior.

13. How Did Our Ancestors Meet?Mate Choice • Male mate choice: he sees attractive female in another band; he pursues. • Female mate choice: based on his appearance and behavior, she either rejects or welcomes him. • Sexual selection imposed: males evolve to convey positive impressions during first moments of interaction • Male mate choice: after time, she agrees to copulate, and after several weeks of copulation, he decides whether to go or stay. • Female mate choice: female making the same decisions: Is he worth my time?

14. 3 Simple Rules to Make Good Sexual Choices 1. “Take the Best”: take the most important quality to you (e.g., beauty and intelligence) and evaluate every potential mate. If one is more intelligent, pick that one; or if not, if one is more attractive, pick that one. -set backs: it takes a lot of time to assess through courtship and conversation the intelligence and attraction you have for a person.

15. 3 Simple Rules to Make Good Sexual Choices 2. “37% Rule”: Interview the first 37% of all potential mates, keeping the best one you find in mind. Then, choose the very next person you interview who is better than that best one. -set backs: There is not enough time to do this nowadays: it would be impossible to date 37% of let’s say Los Angeles’ population before finding the right mate.

16. 3 Simple Rules to Make Good Sexual Choices 3. “Try a Dozen”: “interview a dozen possible mates, remember the best of them, and then pick the very next prospect who is even more attractive.” -humans tend to follow this rule: “we get to know a number of opposite-sex friends during adolescence, fall in love at least once, remember that loved one very clearly, and tend to marry the next person who seems even more attractive. -set backs: people seem to be “satisficing” (looking for good enough, rather than the best) but these rules impose similar sexual selection as any other strategy.

17. Indicators for Qualities Other than Fitness • Energy Level Kindness Indicators: mates who are in good health (in order to survive as partners and parents), and mates capable of cooperation and coordination (so they make an efficient team). -direct benefits of mate choice: food gifts, nests, territories, and fertility -indirect benefits of mate choice: good genes (yet intangible)

18. Indicators for Qualities Other than Fitness Solution: We use direct benefits to obtain indirect benefits. • Assessment of resource-defense ability used by females to get good genes, not resources. (she will copulate with a male who is protecting a food territory for his inherited genes to protect territory, and not for his resources). • Humans do this too: women prefer intelligent men because they would produce intelligent children likely to survive, as opposed to preferring them for the food supply they offer the woman. • In other words: Miller says evolutionary psychology has put too much emphasis on male resources instead of male fitness in explaining women’s sexual preferences.

19. Age and Fertility • Age indicates fertility: before puberty we are infertile. After menopause females are infertile • We have an innate desire to look fertile in order to attract a mate. So we “fool” people into believing we are more fertile than we are. • This term coined neoteny: idea that we have maintained the face of a baby chimp • Miller does not agree with this, and instead says youth indicators may be a form of fitness indicators: -any mate choice mechanism that evolved to favor a condition dependent indicator will tend to favor youth over age simply because youths will display the indicator in a healthier condition.

20. Fitness Indicators for People Other than Mates • Fitness indicators were also used in forming friendships and parent-child relationships; not just for sexual selection. -can explain why “making friends often feels like a variant of sexual courtship.” -similarly, a child says, “hey dad, look at this,” in order to gain approval. The child isn’t trying to “court” his father, he is trying to earn the parent’s affection and support.

21. Mate Choice and Courtship as Social Events • In order to assess our mates “fitness,” what better way than to look at his/her family. If this was so, then relatives would also be under sexual selection to display high fitness. • We may even see this in our own culture: families show off resources when children reach “adulthood” by having bar mitzvahs, quinceneras, etc. -Therefore “cooperative group activities may have evolved as collective courtship displays through sexual selection. -however, Miller says these collective fitness displays were more likely used to intimidate rival groups competing for the same territories and resources. • Family’s views did have an influence on the individual’s decision nonetheless; parent’s would take an interest in offspring's choices and voice their opinions since the sexual choices of their children were so important to the number and quality of grandchildren with their genes.

22. Critical Review • Direct benefits used to assess indirect benefits • Role of Fitness-Indicators • No need for males • Set-up of the Chapter