Buss (1989)
Study 9
Mate preferences
You have to marry one of these people. Who
and why? (they are all actors)
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?
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
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.
Context
3 theories about mate selection
One theory each
Have to explain in a stickman poster
No more than 10 words
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
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.
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?
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: as female fertility is
related to age, we would predict
that men show a preference for
younger women. Preference
less pronounced in women.
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.
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...
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?
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
2. Procedures
Instrument 1: Rating
What issues did you find with the first
questionnaire?
Why not just ask about the four critical
factors?
2. Procedures
Instrument 2: Ranking
Putting 13 characteristics in rank order
What problems are there with ranking?
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?
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
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
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
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
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
3. Findings
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)
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.
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.
…found on the internet
Does this fit with
Buss’s findings?
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…
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.
5. Alternative Evidence
Which woman is most attractive?
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.
5. Alternative Evidence
Which face is more attractive?
5. Alternative Evidence
Which face is more attractive?
5. Alternative Evidence
Which face is more attractive?
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.
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?
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.
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.
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