Performing research on topics related to LGBT people is challenging because very few information sources are entirely objective. The question "How many are there?" exemplifies the challenges of performing accurate research
The Williams Institute on Sexual Orientation and Gender Identity Law and Public Policy at UCLA School of Law has published reports on numbers of Gay, Lesbian, Bisexual and Transgender people in all 50 states, as well as some international reports.
The Gay & Lesbian Atlas (Gary J. Gates and Jason Ost. Washington, D.C. : Urban Institute Press, c2004) includes many references for further research.
Estimates of the number of gay and lesbian populations vary widely for several reasons. One is the definition of what constitutes a "homosexual." Does it require physical expression of same-sex desire, or is fantasizing about it sufficient? Many resist being categorized based solely on this highly personal and often private information. Another reason the actual number living in the United States has been significantly and consistently underreported is due to social taboo, religious censure, legal statutes, real or perceived risk of jeopardizing of jobs, housing, reputations and family situations.
The first scientific attempt to measure the incidence of homosexuality was a study conducted by Dr. Magnus Hirschfeld, the pioneering German sexologist who published The Hirschfeld Report in 1903/4. Of the males surveyed, Hirschfeld concluded that 2.3% were exclusively gay, and 3.4% bisexual.
Alfred C. Kinsey rated sexual orientation on a continuous spectrum of 0 (exclusively heterosexual) to 6 (exclusively homosexual). Based on the in-depth interviews of the predominately white male subjects from the Midwest and Northeast, Kinsey concluded in Sexual Behavior in the Human Male (Alfred C. Kinsey, Wardell B. Pomeroy [and] Clyde E. Martin. Philadelphia, W.B. Saunders Co., 1948) that 10% rated 5-6 and 8% rated 6. Sexual Behavior in the Human Female (the staff of the Institute for Sex Research, Indiana University : Alfred C. Kinsey [and others]. Philadelphia, Saunders, 1953) reported that 2-6% of the 5,940 women reported being more or less exclusively homosexual.
The Ganon and Simon study (Sexual Conduct; the Social Sources of Human Sexuality / John H. Gagnon and William Simon. Chicago, Aldine Pub. Co. ) conducted in 1973 and The Hunt Study in 1974 were roughly in keeping with Kinsey's findings and also subject to similar criticisms.
The National Opinion Research Council published a study in 1988-1991 that was based on data collection in 1970 and 1980 and reported that 6% had ever had an adult homosexual experience.
A study released in 1993 by the Battelle Human Affairs Research Centers in Seattle suggested that only 1% of American men are exclusively homosexual. Serious questions about the methodology have cast doubt upon the uncharacteristically low figures.
The 1993 Janus Report (The Janus Report on Sexual Behavior / Samuel S. Janus and Cynthia L. Janus. Wiley, c1993), the first broad-scale scientific national survey on sexual behavior since Kinsey, concluded that 9% of males and 5% of females had had homosexual experiences more than just "occasionally."
The 1993 Yankelovich Monitor Survey, considered the first nationally representative survey to reflect what percentage of the population identified itself as homosexual, indicated that 5.7% described themselves as "gay/homosexual/lesbian."
The 1994 Sex in America Study (Sex in America: A Definitive Survey / Robert T. Mitchell... et al.. Boston : Little, Brown, c1994) Self-identified gay and bisexual men accounted for 2.8% of the surveyed respondents, while 1.4% of the women identified as lesbian or bisexual.
Revised July 2006.
Revised September 2011.