Genetic Explanations

Women are either bisexual or lesbian, but rarely straight.


When it comes to what turns them on, women are either bisexual or gay, but rarely straight, according to a study published in the Journal of Personality and Social Psychology by the University of Essex.

The study, which involved 345 women using eye tracking devices and direct measurements of genital physiological sexual response, found that “straight” women were strongly sexually aroused by videos of both attractive men and attractive women – even though they reported that they are only sexually interested in men.

This was in contrast to lesbians who showed much stronger sexual responses to women than men. It shows that lesbians are more male-typical in their arousal than “straight” women. It is usually men who show distinct sexual responses to their favourite sex.

According to the author, Dr. Gerulf Rieger, “this shows us that how women appear in public does not mean that we know anything about their sexual role preferences. Men are simple, but women’s sexual responses remain a mystery.”

An understanding of evolutionary biology will demonstrate that women’s sexual response is not a mystery but entirely explainable and predictable.  See below.

This research, published in October 2015, is supported by data in the third National Survey of Sexual Attitudes and Lifestyles  published in The Lancet in November 2013.  It is one of the world’s most comprehensive studies of changing sexual habits and it indicated a big increase in relationships between women.  The number of lesbian encounters has increased fourfold.  The percentage of females who say they have had a sexual “experience”, including kissing, with another woman has increased from 4% to 16%. The number saying they have had sex with another woman has gone up from 2% to 8%.  While the figure for women has increased fourfold in 20 years, for men it has barely changed — 7% for same-sex “experiences” and from 4% to 5% for physical sex.

What has caused this change?  Have women’s desires changed?  If not, are they more likely to live out their fantasies?  Or are they behaving as they have always done, just more likely to admit to same sex relationships in survey?

Many media articles on this subject have postulated the factors which could be “causing” more women to “change” their feeling of sexual attraction towards other women

For example:  seeing more friends indulging in same sex relationships affecting their sexual orientation; internet porn and computer games causing men to fail women sexually, “driving” them into lesbian affairs; recent media exposure to “celebrity lesbians” affecting women’s sexuality; witnessing lesbian relationships in books and films affecting women’s sexuality ……..

These articles are assuming that it is society that “causes” us behave in these ways, that because society expects certain behaviour we are more likely to adopt that behaviour.

None of the media articles commentating on a major survey about one of the most basic, primordial human instincts even mentions how genetics and 3,500,000,000 years of evolution may affect women’s sexual behaviour.

There is a convincing genetic and evolutionary reason why women are more likely to find each other physically attractive and men are less likely to find each other physically attractive.

Evolution is not about survival of the species, it is about survival of the genes.  All living things are a disposable container that has evolved to ensure its genes get moved forward in time.  Living things die.  Their genes don’t.  So any behaviour conferred by those genes, which increases the likelihood of their host having more offspring, will ensure more of those genes are passed to the next generation, amplifying that behaviour in future generations.

Evolution takes a long time.  One tick of the evolutionary clock takes about 250,000 years, so we are virtually identical to our ancestors from a mere 50,000 years ago. And our male and female ancestors have had very different evolutionary pressure over the previous millions of years.  Males and females have consequently evolved very differently.

Human females have a pathetic ability to reproduce, having no more than a dozen pregnancies in their lifetime. Each pregnancy is life threatening and she will generally only produce offspring one at a time. Human children are unusually vulnerable in infancy and take many years to reach maturity.  Women therefore engage in a long, energy sapping and life-threatening investment in their children to ensure these (few) offspring reach childbearing age.  She must choose her mate with great care to ensure her offspring receive beneficial genes from the father, which in turn maximises the chance of her own genes prospering in the next generation.  It also means she must carefully and selflessly look after the few offspring she manages to produce. She (i.e. her genes) has no other choice.  So human females have evolved to be more nurturing.

Human males produce 250,000 sperm every second and their number of offspring is limited only by their opportunity to impregnate willing (or unwilling) females.   Two strategies would work to increase the number of their genes in the next generation:  1. Look after their offspring, nurture them and ensure they reach child-bearing age  (i.e. copy the only strategy available to women);  2. Spread their sperm as far and wide as possible, have thousands of offspring and hope that some reach childbearing age.  A third alternative is the best.  Do both.  Men invest almost nothing in child rearing so it makes sense for them to take huge risks to have the opportunity to reproduce. So human males evolved to be more competitive and risk taking.

Women will choose high social status men (a proxy for good genes) to ensure their own genes have a good chance of survival.  To prove high social status takes a bit longer so women tend to go for successful, older men (4 years older in the UK on average).  Men are programmed to advertise their success and achievements in order to attract a high social status mate.

Men will choose younghealthy, fertile (i.e. physically attractive) women because their chosen mate primarily needs to be fit to survive 9 months of pregnancy and the years of childcare that follows. Men have evolved to visually select a mate on this basis.  Women have evolved for millions of years with this pressure.  Women are therefore programmed to try to look young and attractive in order to find a suitable mate.  Much of this behaviour is hard wired, as is our sexuality and our urge to have sex with attractive members of the opposite sex.  Heterosexual women also need to recognise these traits in their competition (i.e. other women).  Women easily know if another woman is attractive.  So, even heterosexual women have evolved to appreciate the female form, and for some this will go a bit further.  This answers the question  – why women can find each other sexually attractive.

As physical attractiveness is less important to heterosexual men than heterosexual women, men have generally not evolved to know if another man is physically attractive. They tend to compete on success and status.

The desires of men and women have not changed much in 50,000 years, however women are now able to admit to, and indulge in, more lesbian behaviour because we are more tolerant and open about homosexuality.  Technology has allowed anonymous sexual surveys leading to more honesty in answering survey questions; and the anonymity of the internet allows women to meet similar minded women online and explore their sexuality without having to go to a terrifying lesbian club by themselves.

Genetic research consistently shows that the effect of our environment on our behaviour is much smaller and much more transient than we imagine.  This is important because our politicians incorrectly believe they can make big changes to human behaviour by meddling in aspects of public social policy and personal liberty; whereas much of our behaviour is already hardwired by evolutionary processes.

I’m describing the is not the ought of human behaviour, and nothing here should make us believe we can predict the behaviour of individual men and women.  But please remember evolution is about survival of our genes and does not care one jot about human happiness, fairness or equality.

Further Reading:

Getting in touch with our female sexuality

National Survey of Sexual Attitudes and Lifestyles.

Sexual Arousal and Masculinity-Femininity of Women

The Behaviour of Women and Why They Worry About How They Look – an Evolutionary Perspective

Female Bitchiness and Unsisterly Behaviour – An Evolutionary Explanation

Why human societies dislike female sexual promiscuity – an evolutionary explanation

Why Does 50 Shades of Grey Appeal to Women?

Why do male students get more first class degrees at Oxford University than female students?

Men and Women Evolved With Conflicting Interests – Why We don’t Always Get Along


5 thoughts on “Women are either bisexual or lesbian, but rarely straight.

  1. This article completely failed to take into account regarding evolution where a women’s role was to nurture and raise offspring and the male role was to hunt and fight wars. There was a great chance men would not come back from war so women are genetically programmed to be able to adapt and fulfill their emotional and sexual needs with other women who were left in the tribe for the ultimate goal of successfully raising offspring. These liberals who write these articles apply their feminist bias and it’s pretty pathetic. They always attribute sex to pleasure, it’s such a shallow and selfish view of sexuality in general. Humans are DESIGNED to reproduce just like many other animals. It’s fun and cute to always look at sex in terms of pleasure but take the reproductive attribute out of it and you end up with humans only have “fun” for several decades, again, shallow.

  2. Pingback: Chivalry – An evolutionary explanation | RGAmbler

  3. Pingback: Women are either bisexual or lesbian, but rarely straight. | RGAmbler

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