Homosexuality is not caused by genes: the facts

chapter8In his book “My Genes Made Me Do It” (2013) Dr. Neil E. Whitehead analyses the huge amount of scientific research that has proved that homosexuality is not a genetic trait but that it is due to environmental factors. The author works as a research scientist for the United Nations and for the government of New Zealand.

Here are excerpts from chapter 2 (click here) addressing the subject of the great variety of numbers of people with same-sex attractions according to age, culture and place of upbringing. This variety could not exist if homosexuality was a genetic trait. Then it would be constant everywhere, and it isn’t.


Homosexual numbers show  nurture prevails

In the eighties and early nineties, it was widely held that homosexuals were about one in ten of the population. The strongest supporters of the ‘one-in-ten’ figure were gay activists who used it in the campaign for gay rights. Hard on the heels of the ‘one-in-ten’ theory came the ‘gay is inborn’ theory. The two worked together to accomplish considerable changes in attitudes of legislatures, churches, and society in general. If it can be shown that a group of people making up such a large proportion of the population is being discriminated against for something it can do very little about (like skin colour), then people will tend to accept it needs special protections.

But the one-in-ten figure is a myth, though that is still not widely appreciated. All modern sexologists now agree that the early numbers (derived from the surveys of Kinsey in the 1940’s) are far too high. The true percentage of homosexuality gives strong support to an environmentally-induced homosexuality and not genetically.

The Kinsey surveys
So how did the ‘one-in-ten’ myth begin? In 1948 and 1953, sex researcher Alfred Kinsey published two volumes called “Sexual Behavior in the Human Male” and “Sexual Behavior in the Human Female”.
Among Kinsey’s many claims was this one: 13% of men and 7% of women in his study were more or less homosexual for ‘at least three years between the ages of 16 and 55.’ Kinsey said the figures represented measurements of homosexual fantasy and same-sex contact to orgasm. The claim received huge media exposure.

Bruce Voeller, an associate professor at Rockefeller University and a non-practising homosexual, added the 13% and the 7% together and concluded that ‘an average of 10% of the population could be designated as gay’.
“As a scientist I could see how handy it was to use the 10% figure” he said. Voeller, thereafter, became openly gay and was a founder of the modern gay activist movement. He used the figure to drive the campaign for recognition and acceptance:

“As I became a national Gay leader I insisted to other Gay leaders that we needed to bring the message home to the media, to judges and legislators, to ministers and rabbis, to psychiatrists. I campaigned with Gay groups across the country for the Kinsey-based finding that ‘We are everywhere.’ This slogan became a National Gay Taskforce leitmotiv. And the issues became key parts of (our) national, political, educational and legislative programs.

After years of our educating those who inform the public and make its laws, the concept that 10% of the population is gay has become a generally accepted ‘fact’. The 10% figure is regularly utilized by scholars, by the press, and in government statistics. As with so many pieces of knowledge (and myth), repeated telling made it so.”

The problem was that Kinsey’s figures were about four times too high. What was wrong with Kinsey’s work?

It did not use random sampling, which mostly post-dated him. Kinsey had an ideological agenda and was personally biased. Some of the best statistical investigators in the world – Cochran, Mosteller, Tukey – agreed that the procedures adopted by Kinsey and his team inflated the homosexual figures.

Modern surveys
By 2010, more than thirty surveys of homosexual occurrence were based on genuinely representative samples, mostly from Western countries. The results are nowhere near 10% as Kinsey claimed sixty years ago. Around 2.4% of the total adult population is homosexual, lesbian, or bisexual at age 25. The homosexual percentage is nowhere near one in ten of the population.

Implications for the nature/nurture debate
The percentage of homosexuality has important implications for the nature/nature debate.

Homosexual occurrence is too high to be caused by genetic mutation. Most conditions caused by mutation each affect only about 0.025% of the population. At 2.4% the chances of a genetically driven homosexuality is not possible. Homosexuality fits much more naturally into that group of human behaviours which are predominantly psychological in nature.

Surveys of some high-density gay areas, such as parts of San Francisco, do come up with figures about equivalent to Kinsey’s figure of 10%, so we might conclude that his research might be about right for some parts of some large metropolitan areas.
In different countries, modern survey comes up with different percentages of people identifying as homosexual. If SSA is genetically dictated, it should be the same regardless of country, culture or social condition. How diverse or scattered would data be if they were from a trait we know is mostly genetically fixed?

We can see that the data from a known genetic trait, such as height, are very much more consistent between countries than the data on homosexuality. SSA doesn’t look very ‘genetic’ at all. The data differences between countries therefore seems to argue against genetic fixity.

Drop in SSA with age also shows genetic contribution is not fixed.

Homosexuality is not fixed, in fact it is far less stable than heterosexuality. Although the Kinsey surveys of 1948 and 1953 greatly exaggerated homosexual and bisexual numbers, they showed one interesting trend, also borne out by subsequent studies: a steady decline in homosexual fantasy and activity with increasing age compared with heterosexual percentages. In other words, homosexual orientation and behaviour is not a static condition. This has significant implications for arguments that homosexuality is genetically determined. Whatever is genetically determined is, by definition, unable to change within a generation.

The amount of people who identify as homosexual declines with age. Later studies from the large and excellent Chicago Laumann study, also show a strong decrease in homosexual behaviour, this time about four-fold (from age 35 to age 55), with a corresponding drop in those who identify themselves as homosexual or bisexual.

We could sum up OSA/SSA differences like this: SSA tends to be much more intense and preoccupying, but overall, peaks and declines more steeply with age as well. OSA is a relatively sedate affair in comparison and much more readily tends to plateau and express itself to relatively old age.

Wherever the changed homosexual behaviour goes, be it toward the heterosexual end of the Kinsey Scale or into inactivity, the change is considerable, and at odds with a genetically dictated condition stable throughout the life-span.

Urbanisation strongly influences SSA development
The large Laumann Chicago study asked where people had been brought up during ages 14 to 16 and whether they had any male homosexual partners during the last year. The percentages depended on the degree of urbanization; 1.2%of the males surveyed who had been raised in rural areas reported having homosexual partners during the last year; 2.5% who had been raised in medium-sized towns reported having homosexual partners, and 4.4% who had been raised in large cities reported being active homosexuals/bisexuals.

For women, the percentages were 0.7%, 1.3% and 1.6%, respectively. In other words, where you were brought up is quite an important factor in whether you end up having homosexual partners. For the sake of argument let us imagine that the incidence of male homosexuality in rural areas (1.2%) is all due to genetic influence. If that were the case, geneticists would also expect 1.2% of the male population brought up in ‘big cities’ to have a genetically based homosexuality, meaning that the homosexuality of the balance (3.2%) [4.4 minus 1.2] would be exclusively due to social factors. This means that the environmental factor (3.2%) is far more important than the alleged genetic factor (1.2%). For women the environmental factor (0.9% [1.6% minus 0.7%], is slightly more important than the supposed genetic influence (0.7%).

In several other chapters we argue that it is entirely plausible that 90% of homosexuality is accounted for by environmental factors. This very approximate comparison from the Chicago study supports that.


Modern surveys show the homosexual percentage in Western adult populations is much lower than one in ten. About 1% of adult males are exclusively homosexual and about 0.6% of adult women are exclusively lesbian. The figure for bisexuality and exclusive homosexuality combined, rises to about 2.9% for males and 1.8% for females, an average of 2.4% of the total adult population. Much of the bisexual component could comprise homosexuals and lesbians who are or have been married, but, even then, the figure falls far short of Kinsey’s 10%.

The figure in the West however is rising because increasing permissiveness encourages greater sexual experimentation. But this may be superficial social and sexual activity, passing with time, rather than expression of a structured-in orientation.

Both Kinsey’s figures and modern surveys when interpreted show the genetic contribution to SSA is very small and the environmental contribution is much greater.
People move away from homosexual behaviour with age compared with those heterosexual (meaning the condition cannot be life-long genetically determined). The data scatter is too high for homosexuality and bisexuality to sit easily in the genetic category, and the location of upbringing strongly influences SSA development, genetic factors being minor.home-75-p-final


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