SOURCES OF EVIDENCE

1. Universality2. Unique predictions

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>

Only EP makes certain predictions about sex differences

No prediction from other psychological theories

Class survey

“I HAVE BAD NEWS”

Which is worse ?

-studies of personal ads

Men – ask for younger

Women – ask for older

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)

Fact: Women say they want nice guys

Q: Do they really?

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

Kenrick’s Videotape Study

Dominant & nasty Dominant & nice

Submissive & nasty Submissive & nice

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)

Why would it be important?

EP predicts that males should care a lot

•Took photos of subjects

•Morphed some of them into baby pictures

STEP 1

Took photos of student subjects

Morphed some of them into baby pictures

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

?

MALESShowed strong preference for child

resembling them

FEMALESShowed no preference by

resemblance

T.V. remote?

Bath or shower?

Shoes?

1. PARENTAL INVESTMENT

The sex that contributes more to raising offspring

– is more discriminating in sexual mate choice.

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

!

Unique form of emotional attachment to sexual partners

Adaptive for sustaining the relationship

Otherwise the offspring won’t survive

Parental investment sex vs. relationship focus casual sex age preferences

Parental certainty Jealousy Self-similarity of baby

Pair-bonding attachment & love