Dizzyiing Diversity of Human Sexual Strategies (article)

note: we could add one more strategy to the long list in the article, the Taoist strategy; to find someone with an energy body who will speed completion of their Destiny….. Michael

THE DIZZYING DIVERSITY OF HUMAN SEXUAL STRATEGIES
By Mairi Macleod
New Scientist
November 26, 2008

http://www.newscientist.com/article/mg20026841.700-the-dizzying-diversity-of
-human-sexual-strategies.html

Some people revel in a reputation as a Casanova and others proudly proclaim
their chastity. But most of us probably prefer not to advertise our sexual
proclivities. Still, if you think your attitudes to sex are a private affair
consider this. Earlier this year, Lynda Boothroyd of the University of
Durham, UK, and colleagues published a study showing that the majority of
men and women were able to accurately judge whether a person would be a good
bet for a committed relationship or were more interested in a fling, just by
looking at a photograph of their face.

How exactly we make this assessment based on such minimal information is up
for debate, though Boothroyd’s study did yield one clue. She found that men
who were judged to be more “masculine” and women who were considered more
“attractive”, were likely to be seen as more inclined towards casual sex —
and to actually be so (Evolution and Human Behavior, vol 29, p 211).

This surprising talent for accurately reading people’s attitude to sex has
an obvious benefit — it allows us to hook up with a partner who is likely
to want the same out of a sexual relationship as we do. It also raises the
more fundamental question of why individuals have such widely varying
attitudes to sex in the first place. The answer is not simply that beautiful
people have more opportunity. So what does make one person sexually
restrained and another outrageously promiscuous? And how much do our
attitudes to sex depend on factors such as our culture, upbringing,
personality, age and gender?

Among the first researchers to take a scientific look at sexual attitudes
were evolutionary psychologists Jeffry Simpson of Texas A&M University and
Steven Gangestad from the University of New Mexico. Back in 1991, they
devised a questionnaire to measure people’s level of sexual
unrestrictedness, which they dubbed sociosexuality. They found that certain
attitudes and behaviours co-vary — people who tend to have more sexual
partners are also likely to engage in sex at an earlier point in a
relationship, are more likely to have more than one sexual partner at a
time, and tend to be involved in relationships characterised by less
investment, commitment, love and dependency.

Men tend to score high on the sociosexuality scale more often than women,
and evolutionary biologists say there are good reasons for this. Although
men often invest considerably in their offspring, all they actually have to
do to father a child is have sex, so there has been strong evolutionary
pressure for men to be open to short-term relationships. Women, on the other
hand, bear the heavy costs of pregnancy and breastfeeding, and in every
culture they tend to do the bulk of childcare. So they are best off being
choosy about sexual partners, or they might get left holding the baby.

Of course, it is not that simple. Women can be as sexually unrestrained as
men. In fact, there is a huge overlap in the sociosexuality scores of men
and women, with more variation within the sexes than between them. Some
researchers are now trying to explain these subtleties in terms of biology
and evolution.

Take the fact that women’s interest in casual sex can vary wildly over time.
A hint that these short-term sexual encounters might have biological and
evolutionary advantages comes from the timing of them. Several studies have
shown that women are more likely to fancy a fling around the time they are
ovulating — although there is no suggestion that this is a conscious
decision. Not only that, says David Schmitt of Bradley University, Illinois,
women show a shift in preference to men who look more masculine and
symmetrical — both indicators of good genes. Women may have a dual strategy
going, suggests Schmitt. “Humans infants need a lot of help, so we have
pair-bonding where males and females help raise a child, but the woman can
obtain good genes — perhaps better genes than from the husband — through
short-term mating right before ovulation.”

That’s not all. Schmitt has collected data on the sexual behaviour of men
and women from 48 countries across the world and found that while men’s
sociosexuality peaks in their late 20s, women are most likely to be
unfaithful to their partners when in their early 30s. “That’s exactly the
point where the odds of conceiving start to drop at a bigger rate, and it’s
also the point where the odds of having a child with a genetic problem or
birth defect start to go up,” he says. Of course plenty of women have babies
much later, but Schmitt suggests that women’s increased sociosexuality at
around this time reflects an evolved reproductive strategy that maximises
the chances of their conceiving and bearing a healthy child.

So, there may be times when it pays for women to be more sexually
unrestricted, but what about individual differences in sociosexuality? What
makes some women more likely to engage in casual sex at any time than others
— and, for that matter, why is there also such a large variation among men?

One factor is personality. According to Daniel Nettle from the University of
Newcastle, UK, the classically promiscuous man will be high in extroversion,
low in neuroticism and fairly low in agreeableness as well. “The
extroversion gives you the desire to do it,” he says, “the low neuroticism
means you don’t worry too much about doing it and the low agreeableness
means you don’t really care if you mess someone around or cheat on your
wife.” The situation is similar for women, says Nettle, although another
factor, openness, comes into the mix to some extent. This makes sense since
people who are open to experience are likely to want to explore new
relationship possibilities.

Our sociosexuality may also be influenced by early family circumstances.
Developmental psychologist Jay Belsky of Birkbeck College, London, believes
that when children grow up in stressful, unpredictable conditions, perhaps
an absent father or marital conflict, girls in particular get a biological
message to breed sooner and more often because there is no point in waiting
around for a good long-term relationship. “We have new evidence from
longitudinal studies on this,” says Belsky, “showing that harsh parenting in
the first four years of life predicts early puberty and growth and thereby
predicts more unrestricted sexual behaviour by the time the child reaches 15
years of age” (Child Development, vol 78, p 1302).

Schmitt’s survey also reflects this. “In every culture, men that scored
highly on dismissing attachment — which means they think they are important
and other people are not worthy of trust and investment — tended to be more
short-term oriented or higher in sociosexuality.” Such insecurity is thought
to arise from stress during childhood when parents are unresponsive or
unable to give consistent investment. “Secure men tended to be more
monogamous,” he adds. Results for women were similar, and the underlying
factor is trust. “If a person was high in being able to trust other people,
they were monogamous,” says Schmitt. “If they were very low in trust they
were much more likely to be unrestricted in sociosexuality.”

Another factor with strong links to sociosexuality is masculinity. Boothroyd
found men with more masculine-looking faces scored higher on sociosexuality,
and it seems to be the same story for women. Sarah Mikach and Michael Bailey
of Northwestern University in Evanston, Illinois, examined how women’s
sociosexuality related to the degree to which they looked, felt or behaved
in a masculine way. They found that heterosexual women who had high numbers
of sexual partners were more likely to show higher levels of masculinity.

The researchers argued that these women behave in a way that is more
typically male and this could be due to early — probably prenatal —
exposure to androgens, such as testosterone, that organise typically “male”
brains differently from typically “female” brains (Evolution and Human
Behavior, vol 20, p 141). Supporting this idea, Andrew Clark of McMaster
University in Ontario, Canada, found a higher rate of sociosexuality in
women with a smaller ratio of index to ring finger length — which some
researchers believe corresponds to higher prenatal androgen exposure
(Evolution and Human Behavior, vol 25, p 113).

It is not just prenatal testosterone that makes a difference. Peter Gray of
the University of Nevada in Las Vegas and his colleagues found that saliva
samples taken from married men and fathers contained lower levels of
testosterone than in other men. Since testosterone is associated with
competitive and mating behaviour in a wide range of mammals, the researchers
proposed that lower testosterone in fathers allows them to channel more of
their energy into their children (Evolution and Human Behavior, vol 23, p
193). In another study, however, Gray found that testosterone levels are
higher in married men on the hunt for extramarital sexual relationships. So,
are men with lower than average testosterone simply more likely to enter
into a committed relationship, or does being in such a relationship lower
men’s testosterone levels? “In monkeys and rodents, we know the causal arrow
goes both ways,” says Gray. Although there is little data on humans, he
believes it would be surprising if the same were not true of men.

Whether or not testosterone production is affected by the nature of men’s
relationships, the hormone does seem to influence sociosexuality in another
way. There is some evidence that high testosterone levels confer a masculine
appearance, and we know that masculine-looking men are particularly
attractive to women who are looking for short term relationships. Could it
be that such men behave in a sexually unrestricted way because they have
more opportunity to do so?

Schmitt suggests that men with a highly masculine and symmetrical appearance
may come to realise during adolescence that they have what it takes to
attract women for short-term relationships — although they might not know
it consciously. So they go for it, at least while they are young. Meanwhile,
men who have more trouble attracting women for quick flings may have to
settle for monogamy.

So what about particularly attractive women? On the one hand, you might
expect that they would capitalise on their good looks to attract a partner
with good genes and a tendency to be faithful. On the other, like men they
might simply make the most of their increased opportunities for sex and play
the field. Boothroyd’s study certainly found that attractive women had the
highest sociosexuality. However, she points out that her subjects were all
university students in their early 20s who probably hadn’t reached an age
when they wanted to have babies and a committed relationship. Besides, other
studies indicate that the level of sexual restrictedness in women is
generally unrelated to how physically attractive they are (Journal of
Personality and Social Psychology, vol 95, p 1113).

Fuelling the debate, Schmitt says that female attractiveness is likely to
become increasingly related to sociosexuality. He points out that women are
evolved to seek the benefits of short-term flings just a surely as men are,
and argues that when societies become more liberal and equal, then women can
express these preferences. “Historically we’ve repressed women’s short-term
mating and there are all sorts of double standards out there where men’s
short-term mating was sort of acceptable but women’s wasn’t,” says Schmitt.
“When you free a society by giving women ample resources, ample daycare and
so on, then you see high sociosexuality scores in both men and women.” This
is exactly what he and his colleagues found in their cross-cultural study,
with Scandinavian countries emerging as the pinnacle of liberal attitudes
and unrestricted sexual mores.

Fhionna Moore at the University of St Andrews, UK, has also shown that a
woman’s status affects her choice of sexual partner. She found that women
with a high level of control over their own finances tend to place higher
importance on physical attractiveness in a man than on his financial
prospects. Moore points to an intriguing consequence of this. If increasing
female economic power leads to greater demands for good-looking sexual
partners, it may pay men to invest more in their appearance. Given the
explosion in the male grooming industry, it seems that men are already onto
that one.

Cultural evolution is clearly bringing about changes in human behaviour, but
should we expect ever to reach a stage where women and men have equally
unrestricted attitudes to sex? “I think if we constructed a scale to measure
‘sex without commitment with someone you consider especially physically
attractive and socially dominant’ and gave it to men and to women, when the
women were nearing ovulation, women might score higher in many countries
even today,” says Schmitt. But there’s no escaping the fact that women are
the ones who get pregnant and bear children, so it’s is hard to imagine that
all of the differences in what men and woman look for in a relationship will
ever go away.

Individual attitudes to sex vary widely, but so too do cultural ones. In a
survey of 48 countries, David Schmitt of Bradley University, Illinois, found
one reason for this: the higher the number of men relative to women in a
particular society, the less promiscuous the culture was. So for instance,
in east Asian countries such as China, Japan and South Korea, where the
population is heavily male biased there is a relatively low level of
interest in uncommitted, casual sex. Meanwhile, urban areas of the US with
low ratios of men to women, had a correspondingly high level of short-term
relationships and divorce.

This was particularly true, Schmitt says, of
areas that have been hit hardest by some of the harshest drug laws and gang
violence, meaning that many of the men were in prison or dead (New
Scientist, 3 September, p 48)”If ‘good men’ — attractive, faithful,
well-resourced, generous — are few then there will be very high competition
between women to secure them as long-term mates,” says psychologist Anne
Campbell from the University of Durham, UK. “This means men can call the
shots, and what men usually want is casual sex.”

However, most women want a
stable partnership, at least when it comes to having children, and they can
demand such a relationship if men substantially outnumber women, because it
is harder for men to move on to new pastures. “It is a kind of sexual
marketplace where whichever sex is in demand has the power,” Campbell says.