This report references studies from the 1950s to present day. Pleaes note that some of the older information has been superceded by more recent studies, and is included here as an historical document.
This summary sheet is not intended to be a comparative analysis or recommendation of the studies referenced. Its purpose is to respond to inquiries received by the Institute by indicating the range of findings in the research literature, beginning with Alfred Kinsey's two studies, often referred to together as the Kinsey Reports.
Studies often differ sharply in: 1) definitions; 2) methodology; 3) response rates. The majority are based on nonrandom samples. Some look at current/previous year behavior only and others at extended time periods in respondents' lives. They are listed in chronological order.
Kinsey's samples are best for younger adults, particularly the college-educated; they are poorest for minorities and those from lower socioeconomic and educational levels. The original male sample included institutionalized men. Paul Gebhard (Gebhard 1979), a Kinsey research associate and later director of the Institute, described Kinsey's sampling method as "quota sampling accompanied by opportunistic collection" (p. 26). Kinsey's data came from in-depth, face-to-face interviews (with 5300 white males and 5940 white females providing almost all of the data).
Sexual Behavior in the Human Male (1948) and Sexual Behavior in the Human Female (1953) reported that:
In the Final Report and Background Papers of the National Institute of Mental Health's Task Force on Homosexuality (Gebhard 1972), Gebhard reanalyzed Kinsey's data to eliminate sample bias. His refined figures showed that between one-quarter and one-third of adult white males with college education had had an "overt homosexual experience since puberty" (mostly in the adolescent years); weighting by marital status, he estimated that 4% of the white college-educated males and between 1-2% (and closer to 1%) of white females were predominantly or exclusively homosexual.
In The Kinsey Data, Gebhard and Johnson (1979) reexamined the amount of homosexual experience in Kinsey's basic sample of noninstitutionalized males and females. They found 9.9% of the males in the College Sample had extensive homosexual experience. 3.7% of females had extensive homosexual experience.
Tabulations by Gebhard (McWhirter 1990) on Kinsey's basic sample of noninstitutionalized males and females indicated that "13.95% of males and 4.25% of females, or a combined average of 9.13%" had had either "extensive" or "more than incidental" homosexual experience. These figures were not weighted by marital status.
John Gagnon and William Simon (1973) also reanalyzed Kinsey's data, focusing on the college sample. In their tabulations, 30% of males reported a homosexual experience to orgasm for the male or his partner; of this group, 25% had the experience(s) as adolescents or had only isolated experiences before the age of 20. The remaining 5-6% broke down evenly, with 3% having had "substantial homosexual histories" and 3% having had "exclusively homosexual histories." The comparable figure for females having had a homosexual experience was 6%. Of these, 4% had experience limited to adolescence or scattered experience before the age of 20, leaving 2% with significant adult homosexual experience, and less than 1% with exclusively homosexual histories.
Hunt's survey of sexual behavior in the 1970s indicated that 7% of males and 3% of females had homosexual experiences during more than three years of their lives. In comparing his data to Kinsey's, Hunt adjusted Kinsey's 37% figure (for males having had some same-sex contact to orgasm) to 25% and Kinsey's 4% exclusive-homosexuality figure for males to 2-3%. He considered less than 1% of females as "mainly to completely homosexual." This was a volunteer survey of 2036 people using questionnaires.
Pietropinto and Simenauer conducted a large-scale survey of 4066 men in which they asked: "With what type of partner do you usually engage in sex?" 1.3% responded "with men only"; 3.1% responded "men and women." Field agents used a self-administered written questionnaire; participants were recruited at shopping centers, office buildings, sports clubs, colleges, airports, and bus depots.
Comparing national sample surveys from 1970 Kinsey-NORC data and 1988 National Opinion Research Center (NORC) interviews for males, the authors gave an estimated minimum prevalence of 20.3% of adult males having had a homosexual experience to orgasm, with 3.3% of adult men reporting having had homosexual sex "occasionally" or "fairly often" at some point in their adult lives (at age 20 or later).
Harry's telephone survey was based on a national probability sample of 663 males. The survey included a question about sexual attraction to members of the same sex. In the weighted data, 3.7% gave their orientation as bisexual or homosexual.
Tom Smith looked at the sexual behavior data from the 1988 and 1989 National Opinion Research Center's (NORC) General Social Surveys, and classified 5-6% of adults as homosexual or bisexual since age 18 (with the percentage for exclusive homosexuality as less than 1%). The GSS is a probability sample of approximately 1500 people, and nationally representative; the results are based on a one-page self-administered questionnaire on sexual behavior in the last year and since age 18. [Smith has issued a 1998 report of American Sexual Behavior: Trends, Socio-Demographic Differences, and Risk Behavior. He discusses some demographic issues surrounding prevalence of homosexuality. It can be found, in pdf format, from NORC at http://www.norc.uchicago.edu/online/sex.pdf
Janus and Janus, in their cross-sectional (not random) nationwide survey of American adults aged 18 and over, stated that 9% of men and 5% of women reported having had homosexual experiences "frequently" or "ongoing." In another measure, 4% of men and 2% of women self-identified as homosexual. The authors used a questionnaire, supplemented by 125 interviews (4,550 questionnaires were distributed, 3,260 were returned, and 2,765 were usable).
A national survey of 3321 men was conducted in 1991 by Batelle Human Affairs Research Center in Seattle, supported by a grant from the National Institute for Child Health and Human Development, to obtain data on the number of men engaging in sexual behaviors that put them at risk for AIDS. It was a national probability sample of 20-39 year-old noninstitutionalized males. 2% of sexually active men in the survey reported same-gender sexual activity during the last 10 years, with 1% reporting being "exclusively homosexual" during this time (p. 52). Participants were interviewed in person using a standard questionnaire; they also filled out a self-administered questionnaire.
The Harris Poll published a critique of the Batelle 1% figure, comparing it with their own data from a 1988 three-national survey of AIDS' risk behavior conducted for Project Hope's Center for Health Affairs, which found more than 4% of men aged 16-50 and more than 3% of women in the same age group reporting a same-sex sexual partner in the previous five years.
A research team at the University of Chicago headed a project that conducted interviews in 1992 of a random probability sample of 3,432 men and women in the U.S. between the ages of 18-59 (National Health and Social Life Survey). Homosexuality was viewed as a complex of same-gender behavior, desire, and identity. 9% of men and 4% of women reported having engaged in at least one same-gender sexual activity since puberty. Given the identity category choices of heterosexual, homosexual, bisexual, or something else, 2.8% of men and 1.4% of women surveyed reported "some level of homosexual identity."
Data on the prevalence of homosexual behavior and the demographic distribution of homosexual and bisexual men were analyzed from two national probability surveys (General Social Survey - GSS and the National Health and Social Life Survey - NHSLS) and a probability survey of urban centers in the U.S. (National AIDS Behavioral Surveys - NABS) and results from earlier surveys discussed. Combined data from the GSS and NHSLS surveys showed 5.3% of men reporting sexual activity with a same-gender partner since age 18. Data from the NABS showed 6.5% of men reporting sex with men during the previous five years. The highest prevalence was found in central cities of the 12 largest SMSAs (14.4% since age 18) and among "highly educated" White males (10.8%).
A later article on the Hope/Harris survey by Sell reported data on both homosexual attraction as well as homosexual behavior. The figures reported were: 6.2% of U.S. males and 3.6% of U.S. females with "sexual contact with someone of the same sex only or with both sexes in the previous five years," and 20.8% of U.S. males and 17.8% of U.S. females with some homosexual behavior or some homosexual attraction since age 15. The percentage of respondents reporting sexual contact only with others of the same sex in the previous five years in the U.S. was below 1%.
A stratified random sample of males in Calgary, Canada (a metropolitan region of .78 million) was questioned using a computerized response format and three measures of homosexuality. Based on one or more of the overlapping measures, 15.3% of males reported being homosexual to some degree.
In a national survey, 90% of men aged 18-44 considered themselves to be heterosexual, 2.3% as homosexual, 1.8% as bisexual, and 3.9% as 'something else.' Among women aged 18-44 in the same survey, 90% said they were heterosexual, 1.3% homosexual, 2.8% bisexual, and 3.8% as 'something else.'
While about 7% of adult women and 8% of men identify as gay, lesbian or bisexual, the proportion of individuals in the U.S. who have had same-gender sexual interactions at some point in their lives is higher.
Data collected from a national sample of 13,495 men and women between 2006 and 2008. The study attempted to differentiate between sexual attraction, sexual behavior, and sexual identity. The percentage reporting their sexual identity as homosexual ranged from 2% to 4% of males, and about 1% to 2% of females. The percentage reporting their sexual identity as bisexual is between 1% and 3% of males, and 2% to 5% of females. About 4%–6% of males ever had same-sex contact. For females, the percentage who have ever had same-sex contact ranges from about 4% in the GSS, to 11%–12% in the 2002 and 2006–2008 NSFG.
While researchers at the National Academy of Sciences' National Research Council, Committee on AIDS Research and the Behavioral, Social, and Statistical Sciences, Rogers and Turner analyzed estimates from five probability surveys, 1970 to 1990. They gave estimated minimums of 5-7% for males having experienced some same-sex sexual contact in adulthood.
Diamond looked at studies done on the prevalence of homosexual behavior. He included some studies done on populations outside the U.S. The date ranges varied from country to country, but spanned 1948 to 1991. Those studies discussed were compared and displayed in tablular form. He found the mean of males surveyed to be 5.5% of the population, and the median to be 5.3%. The mean of females that engaged in same sex behavior was 2.5% and the median was 3.0%. The calculations were of all non-Kinsey data. Diamond found that methods employed by these studies were inconsistent.
The authors reviewed methods used in defining and measuring sexual orientation, and briefly critiqued surveys of homosexual activity from Kinsey in 1948 to the 1994 study by Laumann, et al. Because of the possible risks involved in self-disclosure, it is posited that the recurrent 2-5% for same-gender sexual behavior in the studies reviewed represents a minimum figure. They suggest that the current prevalence of predominant same-sex orientation is 4-17%.
Hewitt analyzed past surveys on the prevalence of homosexuality in the United States, from 1970 to 1994, looking critically at the methodology of these studies. He offered a metanalysis of the typologies used in these surveys to classify the homosexual. He found five types: (1) open preferential homosexuals, (2) repressed preferential homosexuals, (3) bisexuals, (4) experimental homosexuals, and (5) situational homosexuals.
Gates analyzed information from four recent national and two state-level population-based surveys. The analyses suggest that there are more than 8 million adults in the US who are lesbian, gay, or bisexual, comprising 3.5% of the adult population. He estimated an additional 700,000 individuals identified as transgender.