The 10% figure began as a misinterpretation of studies done in the 1940s by Alfred Kinsey and his associates. Kinsey reported that 37% of males in his studies admitted to experiencing at least one homosexual encounter to the point of orgasm. And he suggested that these figures were underestimates – that the real percentage was even higher.

More recent studies in countries around the world by credible research institutes and universities have consistently shown that less than 3% and perhaps less than 2% of males are homosexually active in a given year. Probably less than 5% of the adult male population engage in sustained homosexual practice over a significant period of adult life. Female homosexuality is estimated to be approximately half or less than the male rates and appears to characterize less than 2% of the female population. This means that claims of 10% are a misrepresentation.

Here is a list of some studies...

1. A study of 5,514 Canadian college and university students under the age of 25 found 1% who were homosexual and 1% who were bisexual. Study by King et al. (1988). Canada, Youth and AIDS Study. Kingston, ON: Queen's University.
   
2. A survey of 135,000 Canadians found that 1.0% of the respondents identified themselves as homosexual and 0.7% identified themselves as bisexual. About 1.3% of men in the study considered themselves homosexual, and 0.7% of the women in the study considered themselves lesbians. Study by Statistics Canada, Canadian Community Health Survey (2003).
   
3. A study of 8,337 British men found that 6.1% had had "any homosexual experience" and 3.6% had "1+ homosexual partner ever." Study by Johnson, A.M. et al. (1992). Sexual lifestyles and HIV risk. Nature, 360(3), Dec. 3, 1992, 410-412.
   
4. A French study of 20,055 people found that 4.1% of the men and 2.6% of the women had at least one occurrence of intercourse with person of the same sex during their lifetime. Study by ANRS: Agence Nationale de Recherches sur le Sida investigators (1992). AIDS and sexual behavior in France. Nature, 360(3), Dec. 3, 1992, 407-409.
   
5. A Danish random survey found that 2.7% of the 1,373 men who responded to their questionnaire had homosexual experience (intercourse). Study by Melbye, M. & Biggar, R.J. (1992). Interactions between persons at risk for AIDS and the general population in Denmark. American Journal of Epidemiology, 135(6), 593-602.
   
6. The USA National Health Interview Survey does household interviews of the civilian non-institutionalized population. The results of three of these surveys, done in 1990-1991 and based on over 9,000 responses each time, found between 2-3% of the people responding said yes to a set of statements which included "You are a man who has had sex with another man at some time since 1977, even one time." Study by Dawson, D. & Hardy, A.M. (1990-1992). National Centre for Health Statistics, Centres for Disease Control, Advance Data, 204, 1990-1992.
   
7. In a random survey of 6,300 Norwegians, 3.5% of the men and 3% of the women reported that they had had a homosexual experience sometime in their life. Study by Sundet, J.M., et al. Prevalence of risk-prone sexual behaviour in the general population of Norway. In Global Impact of AIDS, edited by Alan F. Fleming et al. (New York: Alan R. Liss, 1988), 53-60.
   
8. A national survey of American men found that 1.1% were involved in exclusive same-gender sexual activity over the 10 year period of the study. Study by John Billy, et al. The Sexual Behavior of Men in the United States, Family Planning Perspectives 25 (1993)
   
9. Another study of American men found that 1.6 to 2% had participated in some same-gender sex during the past year and 3.3% had participated occasionally or fairly often since adulthood. Study by Robert Fay, et al. Prevalence and Patterns of Same-gender Sexual Contact Among Men, Science 243 (1989).
   
10. A third study of men in the USA found that 2.7% had participated in same-gender sex in the last year, 4.1% in the last 5 years and 4.9% since age 18. Study by Edward Lauman, et al. The Social Organization of Sexuality: Sexual Practices in the USA. 1994.
    
11. A study of men in the USA, U.K and France found 0.82% (USA), 1.15% (UK) and 0.72% of men had exclusive same-gender sex over a 5-year period. Study by Randall Sell et al. The Prevalence of Homosexual Behaviour and Attraction in the United State, the United Kingdom and France: Results of National Population-based Samples, Archives of Sexual Behaviour 24 (1995).
    
12. Four studies of American men over a 20 year period found the frequency of at least some same-gender sex by men in the last 12 months to be 1.9%, 1.2%, 2.4% and 2.0% respectively. Studies by Susan Rogers and Charles Turner. Male-Male Sexual Contact in the USA: Findings From Five Sample Surveys, 1970-1990. Journal of Sex Research 28 (1991).

Why is there uncertainty about the demographics of sexual orientation?

The demographics of sexual orientation are difficult to establish for a variety of reasons. There is a lack of reliable data. Study participants often avoid answers which they feel society, the survey-takers, or they themselves dislike. The research must measure some characteristic that may or may not be defining of sexual orientation, and that may involve further testing problems. The class of people with same-sex desires may be larger than the class of people who act on those desires, which in turn may be larger than the class of people who self-identify as gay/lesbian/bisexual. In studies measuring sexual activity, respondents may have different ideas about what constitutes a "sexual act." There are several different biological and psychosocial components to sex and gender, and participants may not cleanly fit into a particular category. Studies with random samples containing sufficient numbers of representatives of small sexual minorities are expensive to do. Hence, most studies rely on volunteers who are willing to talk about their sex life, but who do not necessarily reflect the general population.Another significant distinction can be made between what medical statisticians call incidence and prevalence. For example, even if two studies agree on a common criterion for defining a sexual orientation, one study might regard this as applying to any person who has ever met this criterion, whereas another might only regard them as being so if they had done so during the year of the survey. It must also be understood that just because a person has had bisexual or homosexual thoughts does not mean they have an inclination to being bi- or homosexual, or that they will become bi- or homosexual.

Is homosexuality primarily a North American issue?

No. People in Africa, Latin America, Europe, the Middle East and Asia are affected by homosexuality just as in North America. If the same percentage of the population in the East experiences a same-sex orientation then a far larger number of people in the East are affected than in North American because the population the East is much larger than the population of the West.