- Slides: 28
EVOLUTIONARY PSYCHOLOGY PART 2
Evolutionary Theory of Sex Differences: SOURCES OF EVIDENCE 1. 2. Universality Unique predictions
Cross-cultural Research by David Buss sex differences in reproductive behavior are universal Implies that they are built into the genetic code of our species E. g. mating style differences (Clark & Hatfield study)
<catch Figure 11. 3>
Studies testing unique predictions from evolutionary psychology Only EP makes certain predictions about sex differences No prediction from other psychological theories
1. Jealousy differences Class survey “I HAVE BAD NEWS” Which is worse ?
2. Age differences -studies of personal ads Men – ask for younger Women – ask for older
3. Judging Attractiveness Men tend to agree with each other and are not influenced by other factors Women’s judgments of attractiveness are influenced by other features (eg a man’s personality, wealth)
Actual vs. Expressed Choices Fact: Women say they want nice guys Q: Do they really?
Kenrick’s Videotape Study In the pretest, women subjects said that their main criterion for a partner was “a nice guy” Then they were asked to observe videos of men in discussion groups They rated the attractiveness of a certain guy
4 videos of same guy Dominant & nasty Dominant & nice Submissive & nasty Submissive & nice
Results Dominant men were rated as more attractive Niceness did not make a difference BUT -- depends on expected length of relationship (one date vs. lifetime relationship)
4. Parent-Child Similarity:
Do you care if your child looks like you? Why would it be important? EP predicts that males should care a lot
Platek’s Photo Study • Took photos of subjects • Morphed some of them into baby pictures
Method STEP 1 Took photos of student subjects Morphed some of them into baby pictures
STEP 2 Brought the same subjects back to rate baby pictures One picture is a morph of the subject & baby face Subjects were asked to rate: Which baby is more attractive ? Which baby would you adopt ? Which baby would you spend money on ?
Results MALES Showed strong preference for child resembling them FEMALES Showed no preference by resemblance
Other sex differences ? T. V. remote? Bath or shower? Shoes? Car racing?
Evolutionary Explanation of sex differences 3 principles
1. PARENTAL INVESTMENT The sex that contributes more to raising offspring – is more discriminating in sexual mate choice.
2. Parental Certainty Females are more certain that a baby is theirs But Males are not sure and so have to be more concerned They need to avoid wasting their resources on unrelated offspring e. g. Maury Povich T. V. show
Is evolutionary psychology all bad news for male-female relationships? NO !
3. Pair-Bonding Unique form of emotional attachment to sexual partners Adaptive for sustaining the relationship Otherwise the offspring won’t survive
Common in other animals too We call it attachment or love
Summary: Applying EP principles to Explain Sexual motivation Parental investment sex vs. relationship focus casual sex age preferences Parental certainty Jealousy Self-similarity of baby Pair-bonding attachment & love