Buss (1989)

1. Buss (1989) Study 9

2. Mate preferences • You have to marry one of these people. Who and why? (they are all actors)

3. Evolutionary recap • Bennett-Levy and Marteau = evolution of phobias for survival • Buss = evolution of mating preferences for reproduction • What behaviour would lead to increased/ decreased success at reproduction?

4. 1. Context • If humans have evolved, characteristics that increase the success of reproduction should appear more often in the population • Thornhill and Thornhill (1983) • People lacking these characteristics will not be able to mate and to become people’s ancestors

5. 1. Context • Current mate preference is of interest to evolutionary psychologists as it tells us about past reproductive history. • Mate preference is important, but little is known about the characteristics which are valued by males and females.

6. Context • 3 theories about mate selection • One theory each • Have to explain in a stickman poster • No more than 10 words

7. 1. Context • 1. Prediction based on parental investment (Trivers, 1972) • Who invests the most time, energy and resources in raising children? • Female investment is huge, while male investment is minimal

8. 1. Context • 1. Prediction based on parental investment • Prediction: women will look for men who can offer resources and protection for both her and her future children • In modern times, this might not be food and shelter, as much as money and status.

9. 1. Context • 2. Prediction based on reproductive value (Symons, 1979) and fertility (Williams 1975) • Fertility: probability of reproducing now • Reproductive value: probability of reproducing in the future • 35 year old vs 10year old • Male vs female • What age would the ideal mate be?

10. 1. Context • 2. Prediction based on reproductive value and fertility • Youthfulness is a sign of both fertility and reproductive value: good skin, muscle tone full lips and healthy hair • Prediction: asfemale fertility is related to age, we would predict that men show a preference for younger women. Preference less pronounced in women.

11. 1. Context • 3. Prediction based on paternity probability (Daly et al, 1982) • How certain can a woman be that any child she has is hers? • How certain can a man be that his mate’s child is his? • Males want to be certain that they are investing time and resources into their own offspring.

12. 1. Context • Prediction based on paternity probability • Prediction: males should show a greater preference for women who are chaste (i.e. virgins) • As women know that any child they have is theirs, this will be less important • However, males with other partners might have to share resources...

13. 1. Aim • To investigate if evolutionary explanations for sex differences in human mate preferences are found cross culturally • Why use cross cultural studies for evolutionary theories?

14. 2. Procedure • Buss used a questionnaire which assessed preferences for particular traits in potential mates • Using pg 117 in the book, find out the missing information about the participants • Identify the sampling techniques used

15. 2. Procedures • Instrument 1: Rating • What issues did you find with the first questionnaire? • Why not just ask about the four critical factors?

16. 2. Procedures • Instrument 2: Ranking • Putting 13 characteristics in rank order • What problems are there with ranking?

17. 2. Procedures • Translations • Translated into local languages • Avoiding of gender specific terms • Adapted to fit customs • Co-habiting in Sweden • Polygyny in Nigeria • Is this a strength or a weakness?

18. 3. Findings • Significance recap: If it is “significant” there is less than a 5% probability that it is due to chance • Financial prospects: in 36/37 samples women valued “good financial prospects” higher than men. • Large variation between and within cultures in importance. High value in Africa, Asia and America. Lower in Europe

19. 3. Findings • Ambition and industriousness • In 34/37 samples females desired ambition higher than males • 3/37 males had a higher preference in women • In these cultures, women carry out many physical tasks • Not rated low in any sample, although UK, Germany, Netherlands and Finland showed less preference

20. 3. Findings • Age Difference • In every sample, men preferred younger women (2.66 years) • Mean age men want to marry: 27.49 years. Therefore ideal age for females to be is 24.83 • This is closer to peak fertility rather than peak reproductive value

21. 3. Findings • Age differences • Females preferred older men (3.42 years) • Mean age females want to marry: 25.39 years. Therefore ideal age for males to be is 28.81 • Where polygyny is common, desired age difference for men is bigger • In these cultures, men are older when they marry

22. 3. Findings • Good Looks • In all samples, men rated good looks as more important than women • Chastity • Large variation in the importance of chastity • In 23/37 males valued chastity as higher than females. • Important in China, India, Indonesia, Iran Taiwan and Palestine • Seen as irrelevant in most European samples

23. 3. Findings

24. 3. Conclusions • There are five conclusions in this study. Each one relates to one of the three theories from the context. • Read the conclusions and match to the theory (use the psychologists names)

25. 3. Conclusions • How do Buss’s findings support the general notion of mating behaviour being innate? • Traits are universal. If they were all different, we could argue it is due to culture. But as they are the same everywhere, is suggests a biological basis for behaviour. Also, the behaviour shown matches what we would predict from evolutionary theory.

26. 3. Conclusions • Mating behaviour differs by gender. This reflects the differences in the reproductive capacities of males and females. • Unlike animals, human mate preference is not simply about female choosiness. Males and females both express preferences. • However, Buss also highlighted that there are cultural influences as well. This is demonstrated by the large differences in preferences for chastity between cultures.

27. …found on the internet • Does this fit with Buss’s findings?

28. 5. Alternative Evidence • Buss found that physical attractiveness was rated highly by nearly all male samples. But why? • What is “attractiveness”? Is it the same in all cultures? Why… Not…

29. 5. Alternative Evidence • Cunningham et al (1995): close agreement across cultures in female physical attractiveness. • Native Asians and Hispanic students and white Americans rated attractiveness of Asian, Hispanic, black and white women. • Mean correlation between groups in attractiveness ratings was +0.93.

30. 5. Alternative Evidence • Which woman is most attractive?

31. 5. Alternative Evidence • Singh (1993): waist to hip ration (WHR) related to physical attractiveness across cultures. • Men prefer women who have a low WHR. • A woman with this WHR is likely to have a large bottom (good fat reserves for pregnancy) and a narrow waist (indicating that she is not pregnant) • Low WHR would is attractive because it is a sign of youthfulness and fertility.

32. 5. Alternative Evidence • Which face is more attractive?

33. 5. Alternative Evidence • Which face is more attractive?

34. 5. Alternative Evidence • Which face is more attractive?

35. 5. Alternative Evidence • Facial symmetry may be a sign of genetic strength. Therefore, symmetrical faces may be more attractive. • Little et al (2007) examined preferences for symmetry in both the UK and the Hadza, a primitive hunter gatherer society in Tanzania. • Both groups preferred symmetrical faces, and this was the strongest in the Hadza.

36. 5. Alternative Evidence • Schmitt (2003) • 16,288 people from 53 countries • Found universal differences between Male and Female mate choice. • Found in ALL countries men desired a larger number of mates than women did. • What does this suggest about Buss’s conclusions?

37. 5. Alternative Evidence • How much do people's stated preferences actually reflect their choices? • Waynforth and Dunbar (1995) content analysis of 900 lonely hearts ads, and noted differences in what men and women want. • More men than women sought a youthful mate • More men sought a physically attractive mate • More women used physically attractive terms to describe themselves • More men reported their economic status/earning power when describing themselves.

38. 5. Alternative Evidence • Buss focused on heterosexual relationships. Can we apply to homosexual relationships? • Dunbar (1995) looked at gay personal ads, • Heterosexual women were three times more likely to seek resources and status then lesbians, • Gay men offered resources about half as often as heterosexual men. • This supports the evolutionary explanation; we would not expect lesbian and gay mate choice to be related to reproductive criteria.

39. 5. Alternative Evidence • Dunbar also notes that times have changed, • Women have their own economic security, are less interested in a partner’s resources. • Seek instead a caring, sharing partner instead • This still makes evolutionary sense because that kind of partner should still enhance reproductive success. • Use three colours to highlight research that supports, contradicts,or develops Buss’s research