Introduction to Psychology
Suzy Scherf
Lecture 14: How Do We Interact?
Human Mating Strategies
Don’t Men and Women have the Same
Mate Preferences?
What if someone of the opposite sex approached you and began a
conversation. You find this person attractive and pleasant to talk to.
After a few moments of conversation they ask you either:
1. “Would you go out with me tonight?”
2. “Would you come over to my apartment tonight?”
3. “Would you go to bed with me tonight?”
How would you respond?
Don’t Men and Women have the Same
Mate Preferences?
1. “Would you go out with me tonight?”
Men:
Women:
% Yes, % No
% Yes, % No
2. “Would you come to my apartment tonight?”
Men:
% Yes, % No
Women: % Yes, % No
3. “Would you go to bed with me tonight?”
Men:
% Yes, % No
Women: % Yes, % No
Sexual Selection
• Traits spread b/c they -
• Sexual Selection favors traits that -
• Often acts unevenly in the two sexes because of
differences in _________________.
Sexual Selection: The Peacock
Sexual Selection
• When males > females reproductive rate
(most mammals):
1.
2.
• Sexual selection favors traits that help increase the
____________ in the fast sex:
•
Sexual selection favors traits that help increase the
_____________ in the slow sex:
The Case of Humans
Women can produce about 1 child/year
•
• in EEA probably limited to about
• breast milk only food for infants
Would increasing the number of partners increase her
reproductive rate?
The Case of Humans
Men can produce an unlimited number of children/year
•
•
Would increasing the number of partners increase his
reproductive rate?
The Case of Humans
Men do tend to invest in their offspring
•
•
In a perfectly monogamous system, the men’s and
women’s reproductive rates would be _________.
Human mating systems approach monogamy -
Evidence for a Mostly Monogamous
Mating System
• In _____% of human cultures allow polygyny!
• Prohibitions on polygyny are very recent (≈ 500
years)
• Marital infidelity
• Marriage, divorce, re-marriage
The extent of polygyny =
Sexual Selection in Humans
• Members of the fast sex _________
• Members of the slow sex _________
• Because of a tendency toward weak polygyny:
•
•
• Sexual Selection can ____________ that influence
competition and choosiness behaviors
Are Men More Competitive and are
Women more Choosy?
1. “Would you go out with me tonight?”
Men: 50%
Women: 50%
2. “Would you come to my apartment tonight?”
Men: 69% Yes
Women: 6% Yes
3. “Would you go to bed with me tonight?”
Men: 75% Yes
Women: 0% Yes
Are Men More Competitive and are
Women more Choosy?
Likelihood of consenting to intercourse
1. Women are more __________ than men.
2. Men aren’t ___________
5 yrs
Time Known
1 hr.
How does Parental Investment Influence
Mating Strategies?
Parental investment - anything that a parent does for a
particular offspring that ______ the offspring and
____________________ to invest in other offspring.
•
•
•
• __________ investment in humans
• most likely to evolve in species with -
How does Parental Investment Influence
Mating Strategies?
• Parental investment is different for men and women
• Women have obvious ________________
• Men do not make the ____________________,
but do invest with other resources • Women make _____________ and ____________
investments in their offspring, while men only
invest ________________
How does Parental Investment Influence
Mating Strategies?
Any trait that _____________________________in
women should be selectively preferred in men.
Any trait that helps a woman
_________________________________will spread!
Any trait that indicates
__________________________should be selectively
preferred in women.
Mating Preferences in Men and Women
Physical Attractiveness:
Perceptions of attractiveness have been shaped by
evolution as indicators of fitness Correlates of Fitness that shape our attractiveness
judgments many are indicators that the person is not
too stressed by _____________
1.
2.
3.
4.
5.
Mating Preferences in Men and Women
Physical Attractiveness:
Symmetry
Face Symmetry
Face Symmetry
Face Symmetry
Face Symmetry
Face Symmetry
Face Symmetry
Mating Preferences in Men and Women
Physical Attractiveness:
Men and women have equal criteria for attractiveness
What’s Different between the Sexes?
•
• Across cultures, men overwhelmingly -
Mating Preferences in Men and Women
Why do men place a higher emphasis on physical
attractiveness?
• Physical attractiveness is an indicator of
physiological health -
• Attractiveness is an indicator of -
Mating Preferences in Men and Women
What other indicators of
potential fecundity do
men attend to in mate
selection?
How attractive is this
woman?
How attractive is this woman?
How attractive is this woman?
Waist-Hip Ratio
WHR =
WHR =
WHR =
Waist-Hip Ratio is Related to
Fecundity
• Higher WHR is correlated with __________ and
higher susceptibility to a range of
________________
• High WHR reflects a low level of __________ - as
in pregnancy women, prepubescent girls, and postmenopausal women
• Really low WHR probably does not exist in nature
Waist-Hip Ratio is Related to
Fecundity
• An increase from .7 to .8 in WHR results in a ____%
decrease in likelihood of pregnancy
• A woman’s WHR does reflect her -
Mating Preferences in Men and Women
When might women place a high emphasis on the
physical attractiveness of their mate?
•
• Sneaker-strategy
Mating Preferences in Men and Women
What kind of traits to women place as a higher
priority for mate selection than do men?
•
• WHY?
Sex Differences in
Reproductive Strategies
1. Reflect differences in reproductive rate –
2. Reflect mate preferences -
3. Women looking for __________ and ___________
resources in men
4. Men looking for ____________
Sex Differences in
Reproductive Strategies
5. Women’s genes and investment 6. Men’s genes and investment -
As a result, there is an asymmetry between men’s and
women’s _____________________
Sex Differences in Parental Confidence
How confident are you in your ability to identify
your own offspring?
•Women (and her relatives) are _______%
confident in her ability to identify her offspring
•Men (and his relatives) are ___________%
confident in his ability to identify his offspring
Sex Differences in Parental Confidence:
Women
•Since a man’s investment and his genes are not
automatically linked, -
•This opportunity to recruit these resources
separately results in a
_______________________
Sex Differences in Parental Confidence:
Women
•Women trying to get the best of both worlds
•A strategy focused only on getting the best genes or
only on getting the most resources from men is not
as successful as a _________________
Women’s Mixed Reproductive Strategy
A woman playing a mixed reproductive
strategy will accept genes and resources
from different men!
Sex Differences in Parental Confidence:
Men
•Since men never have complete parental confidence
they risk being cuckolded
•Cuckoldry -
• There is some selection pressure on men to -
Men’s Mixed Reproductive Strategy
A man playing a mixed reproductive
strategy will invest heavily in one
partner and her offspring but still
attempt to attract additional mates.
Mixed Reproductive Strategies
If you ask about men’s and women’s selectivity
across several characteristics and many levels of
involvement:
1. Women set higher standards than men -
2. Setting high standards eliminates potential mates -
Mixed Reproductive Strategies
3. Women set higher standards on attractiveness for -
4. Overall, both men and women set the highest
standards -
5. Men relax their standards on all characteristics for
their -
Counter-Strategies
Men’s and women’s mixed reproductive strategies are
often in ________________ with one another.
How do men and women’s mating strategies deal
with this competition?
Both men and women have developed
___________________ in their mating strategies
such that men are sensitive to _____________ and
women are sensitive to men’s
_______________________
Counter-Strategies: Men
Men have to avoid investing in offspring that aren’t
genetically related to them.
Men have evolved a counter-strategy to giving
investment where there are no genes.
1.
2.
Counter-Strategies: Men
Men rate _________________________
characteristic in a long-term mate and
___________________ as the most negative trait in a
long-term mate!
On the other hand, men don’t show a preference for
fidelity in a _________________ mate.
Counter-Strategies: Men
• In fact, men are ___x more likely to divorce a
woman if he has low paternity certainty in their
children and they are much less likely to invest in
these children after the divorce!
• Women intuitively know this about men and seem
to use this sensitivity to the risk of cuckoldry in
competing for mates.
Counter-Strategies: Women
• When a man invests in another woman and her
offspring, -
• Women have also developed counter-strategies to
defend against -
Counter-Strategies: Women
• Women are much more threatened by -
• Emotional infidelity is a stronger signal to women
that -
Facultative Influences on
Reproductive Strategy
Why are some individuals so jealous?
Why do some women seem to lower their
reproductive fitness by having many sexual partners?
Why don’t some men invest at all in their offspring?
Facultative Influences on
Reproductive Strategy
One essential factor may be
___________________________________________
In particular, the abundance of investing men predicts
the -
Facultative Influences on
Reproductive Strategy
Lots of Investing
Males
Women
Men
Few Investing Males
Facultative Influences on
Reproductive Strategy
In fact, children show lasting responses to the
presence or absence of a father as an indication that
investing males are scarce.
• Girls reared in father-absent homes -
• Boys reared in father-absent homes -
Facultative Influences on
Reproductive Strategy
Adult’s expectations about the necessity of male
paternal investment influence their mate-attracting
strategy.
• Women who believe that investing males are scarce -
• Women who believe that there are an abundance of
investing males -
Facultative Influences on
Reproductive Strategy
Adult’s expectations about the necessity of male
paternal investment influence their mate-attracting
strategy.
• Men who believe in the scarcity of investing males -
• Men who believe that there are an abundance of
high investing males -
Facultative Influences on
Reproductive Strategy
• When men and women assume male investment to
be rare in the population, they both show -
• When men and women assume male investment to
be frequent in the population, they behave in ways
that -