Sexual Motivation
Sex Is Natural
• We are all motivated to have sex.
• Without that motivation, none of us would
be here.
How do we (as scientists) find out about sex?
We ask!!!!
Alfred Kinsey’s Studies
• Held confidential interviews
with 18,000 people (in early
1950’s) about their sexual
behavior and attitudes.
• He found most men and half
of all women of that time
had premarital sex and did
other various sex acts.
• His study and results
shocked many and angered
others
Why??
Why was Kinsey important?
#1
 first
to use scientific method to study sex
 showed us that our perceptions about what
others are doing are a whole lot different
than the reality

#2
i.e. – sex and certain sexual behaviors where only
done by a few deviants – but actually they are
done by most normal people – even your parents!!
 he
denounced, in his opinion, the “repressive
social attitudes” of his time

This opened the flood-gates to research in this
field
Good Start- but major problems with
his study- sampling, questions etc….
 Sample was not random
 mostly well-educated, white city dwellers
 Asked many leading questions to gather data
Misinformation effect
 May have let his own beliefs influence his
results
Experimenter bias
Masters and Johnson
The Physiology of Sex
 Set out to explore the physiology (biology) of
sex.
 Started a study with 382 females and 312
males.
 Filmed more than 10,000 sex cycles over a 20
year period
 Only people who were willing to have sex in a lab
environment were asked to participate.
 This was a big problem for the test as far as
reliability and validity
Results of M & J Study
The highlight of their research was the
biological breakdown of sex called…
The Sexual Response Cycle
1. Excitement Phase
2. Plateau Phase: excitement phase
peaks, breathing, pulse increases
3. Orgasm
4. Resolution Phase: body returns to
normal resting states
– men MUST experience a refractory
How is a high dive similar to
period
the Sexual Response Cycle?
– time must elapse before the cycle can
repeat
– women do not have a similar refractory
period and can repeat the cycle immediately
The Psychology of Sex
• Many studies point to psychological rather
than biological factors for sexual motivation
– Unlike many animals, our sexual desire is not
motivated strictly by hormones
• Only some people are externals when it
comes to hunger - but we are all externals
when it comes to sex.
– People can find sexually explicit images either
pleasing or disturbing- but they are none the less
biologically arousing.
Can External Sexual Stimuli have
negative effects?
• Movies of women being coerced or forced into
sex tend to increase the viewer’s acceptance of
the false idea that women can enjoy it.
• Viewing X-Rated films can diminish people’s
satisfaction with their own partners.
– Expectations change.
– After viewing attractive women or men on TVpeople judge their own partners as less attractive.
Adolescent Sexuality
Culture
•About ½ of all high school kids in US report having sex- rates are higher in Western
Europe but lower in Arab or Asian countries.
Also change over time in the same culture: in 1900 3% of women reported having
sex by 18. Now that number is around half.
We have discussed the energizing of sexual
motivation but have yet to discuss its direction:
Sexual Orientation
• A sexual attraction toward members of
either one's own gender or the other
gender.
The Brain
Simon LeVay
• discovered a cluster of cells in the
hypothalamus that is larger in heterosexual
men than in heterosexual women or
homosexual men.
• However, this cluster could be socially
developed or by some other biological
factor.