Demographics of sexual orientation

The demographics of sexual orientation are difficult to establish for a variety of reasons. One of the major reasons for the difference in statistical findings regarding homosexuality and bisexuality has to do with the nature of the research questions. Major research studies on sexual orientation are discussed. Most of the studies listed below rely on self-report data, which poses challenges to researchers inquiring into sensitive subject matter. More importantly, the studies tend to pose two sets of questions. One set examines self-report data of same-sex sexual experiences and attractions while the other set examines self-report data of personal identification as gay, lesbian, or bisexual. Fewer research subjects identify as gay, lesbian, or bisexual than report having sexual experiences or attraction to a person of the same sex. Several studies of sexual orientation in countries provide comparative perspectives. Tables comparing several U.S. cities' population numbers are also included.

Homophobic settings may mean that some LGBT people may not openly identify as such, and open identification of one's true sexual orientation may depend on the status of LGBT rights in a given location.

Incidence versus prevalence
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. However, it must be understood that sexual orientation refers to an enduring pattern of emotional, romantic, and/or sexual attractions to men, women, or both sexes. Sexual orientation also refers to a person’s sense of identity based on those attractions, related behaviors, and membership in a community of others who share those attractions. Therefore, a person can be celibate and still identify as being bisexual or homosexual based on romantic proclivities.

Western perception of homosexuality versus the rest of the world
The population that has come to be referred to as "gay" in the West is not a descriptive term that would be recognized by all men who have sex with men (MSM) as known in the rest of the world. While gay culture is increasingly open and discussed, the world of MSM consists of a diverse population that often may respond differently depending on how communications in clinical settings are framed. "Gay" is generally used to describe a sexual orientation, while "MSM" describes a behavior.

Some men who have sex with other men will not relate to the term "gay" or homosexual, and do not regard sex with other men as sexual activity, a term they reserve for sexual relations with women. This is particularly true among individuals from non-Western cultures. Nevertheless, it is common in the US. Terms such as MSM or “same gender loving” are often used in place of the word gay. Men in Africa and Latin America engage in sexual relationships with other men while still referring to themselves as 'heterosexual', which is known as being on the "down-low". The same is true of men who engage in homosexual activities in the military, gender-segregated schools and universities, or prison; most of them do not consider themselves gay but still engage sexually with members of their own sex in order to fulfill their desires.

There is a lack of information on sexual behaviour in most developing countries. The limited sources that are available indicate that although homosexual self-identification might occur relatively infrequently, the prevalence of homosexual behaviour is higher. These men are not taken into consideration in some sexual identity surveys which may lead to under-reporting and inaccuracies.

Importance of having reliable demographics
Reliable data on the size of the gay and lesbian population would be valuable for informing public policy. For example, demographics would help calculate the costs and benefits of domestic partnership benefits, of the impact of legalizing gay adoption, and of the impact of the US military's Don't ask, don't tell policy. Further, knowledge of the size of the "gay and lesbian population holds promise for helping social scientists understand a wide array of important questions—questions about the general nature of labor market choices, accumulation of human capital, specialization within households, discrimination, and decisions about geographic location."

The Kinsey Reports
Two of the most famous studies of the demographics of human sexual orientation were Dr. Alfred Kinsey's Sexual Behavior in the Human Male (1948) and Sexual Behavior in the Human Female (1953). These studies used a seven-point spectrum to define sexual behavior, from 0 for completely heterosexual to 6 for completely homosexual. Kinsey concluded that a small percentage of the population were to one degree or another bisexual (falling on the scale from 1 to 5). He also reported that 37% of men in the U.S. had achieved orgasm through contact with another male after adolescence and 13% of women had achieved orgasm through contact with another woman.

His results, however, have been disputed, especially in 1954 by a team consisting of John Tukey, Frederick Mosteller and William G. Cochran, who stated much of Kinsey's work was based on convenience samples rather than random samples, and thus would have been vulnerable to bias.

Paul Gebhard, Kinsey's successor as director of the Kinsey Institute for Sex Research, dedicated years to reviewing the Kinsey data and culling its purported contaminants. In 1979, Gebhard (with Alan B. Johnson) concluded that none of Kinsey's original estimates were significantly affected by the perceived bias, finding that 36.4% of men had engaged in both heterosexual and homosexual activities, as opposed to Kinsey's 37%.

Modern survey results
Since most of the surveys mentioned are based on door-to-door or telephone-based statistics, the numbers and percentages mentioned are strongly likely to be under-reported since most LGBT people live in fear of being outed by their local authorities and mostly their family members, therefore choose to hide their real sexual identity.

Recent critiques of these studies have suggested that because of their dependence on self identification, they may have under counted the true prevalence of men with a history of same sex behavior and/or desire.

Australia
The largest and most thorough survey in Australia to date was conducted by telephone interview with 19,307 respondents between the ages of 16 and 59 in 2001/2002. The study found that 97.4% of men identified as heterosexual, 1.6% as gay and 0.9% as bisexual. For women 97.7% identified as heterosexual, 0.8% as lesbian and 1.4% as bisexual. Nevertheless, 8.6% of men and 15.1% of women reported either feelings of attraction to the same gender or some sexual experience with the same gender. Half the men and two thirds of the women who had same-sex sexual experience regarded themselves as heterosexual rather than homosexual.
 * 2003

Canada
A study of 5,514 college and university students under the age of 25 found 1% who were homosexual and 1% who were bisexual.
 * 1988

Denmark
A random survey found that 2.7% of the 1,373 men who responded to their questionnaire had homosexual experience (intercourse).
 * 1992

France
A 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.
 * 1992

Ireland
A study of the responses of 7,441 individuals, conducted by the ESRI, found that 2.7% of men and 1.2% of women self-identified as homosexual or bisexual. A question based on a variant of the Kinsey scale found that 5.3% of men and 5.8% of women reported some same-sex attraction. Of those surveyed, 7.1% of men and 4.7% of women reported a homosexual experience some time in their life so far. It also found that 4.4% of men and 1.4% of women reported a "genital same-sex experience" (oral or anal sex, or any other genital contact) in their life so far. The study was commissioned and published by the Crisis Pregnancy Agency in partnership with the Department of Health and Children.
 * 2006

New Zealand
In an anonymous survey of 8,000 New Zealand secondary school students conducted by the University of Auckland, 0.9% of those surveyed reported exclusive attraction to the same sex, 3.3% to both sexes and 1.8% to neither.
 * 2007

Norway
In a random survey of 6,300 Norwegians, 3.5% of the men and 3% of the women reported that they had a homosexual experience sometime in their life.
 * 1988

According to Durex Global Sex Survey for 2003, 12% of Norwegian respondents have had homosexual sex.
 * 2003

United Kingdom
A study of 8,337 British men found that 6.1% have had a "homosexual experience" and 3.6% had "1+ homosexual partner ever."
 * 1992

HM Treasury and the Department of Trade and Industry completed a survey to help the government analyse the financial implications of the Civil Partnerships Act (such as pensions, inheritance and tax benefits). They concluded that there were 3.6 m gay people in Britain—around 6% of the total population or 1 in 16.66 people.
 * 2005

A representative survey of 238,206 Britons, exclusive to their categories, found 1% identified as gay or lesbian and 0.5% said they were bisexual. A further 0.5% self-identified as "other", and 3% responded as "do not know" or refused to answer. In total this adds up to 5% of people who do not identify as heterosexual. Ben Summerskill, chief executive of the gay equality charity Stonewall stated: "This is the first time that people were asked and data collection happened on doorsteps or over the phone, which may deter people from giving accurate responses - particularly if someone isn't openly gay at home." Stonewall worked with 600 major employers and their experience had shown that these statistics increased when people were regularly asked about sexual orientation as part of general monitoring information. It was therefore suggested that much of the 3% who responded with 'do not know', or refused to answer, may simply be homosexual or bisexual and a percentage of people may have lied when they claimed to be heterosexual.
 * 2010

The Integrated Household Survey, produced by the Office of National Statistics, gives the following figures for the period April 2011 to March 2012:
 * 2011


 * 1.1 per cent of the surveyed UK population, approximately 545,000 adults, identified themselves as Gay or Lesbian.
 * 0.4 per cent of the surveyed UK population, approximately 220,000 adults, identified themselves as Bisexual.
 * 0.3 per cent identified themselves as ‘Other’.
 * 3.6 per cent of adults stated ‘Don’t know’ or refused to answer the question.
 * 0.6 per cent of respondents provided ‘No response’ to the question.
 * 2.7 per cent of 16- to 24-year-olds in the UK identified themselves as Gay, Lesbian or Bisexual compared with 0.4 per cent of 65-year-olds and over.

Ratios of proportions
In general, most research agrees that the number of people who have had multiple same-gender sexual experiences is fewer than the number of people who have had a single such experience, and that the number of people who identify themselves as exclusively homosexual is fewer than the number of people who have had multiple homosexual experiences.

Change over time
In addition, major historical shifts can occur in reports of the prevalence of homosexuality. For example, the Hamburg Institute for Sexual Research conducted a survey over the sexual behavior of young people in 1970 and repeated it in 1990. Whereas in 1970 18% of the boys ages 16 and 17 reported to have had at least one same-sex sexual experience, the number had dropped to 2% by 1990. "Ever since homosexuality became publicly argued to be an innate sexual orientation, boys' fear of being seen as gay has, if anything, increased", the director of the institute, Volkmar Sigusch, suggested in a 1998 article for a German medical journal.

Brazil
In 2009, in a survey conducted by University of São Paulo in 10 capitals of Brazil, of the men 7.8% were gay and 2.6% were bisexual, for a total of 10.4%, and of the women 4.9% were lesbian and 1.4% were bisexual, for a total of 6.3%.

Of the men of the city of Rio de Janeiro, 14.3% were gay or bisexual. Of the women of the city of Manaus, 10.2% were lesbian and bisexual.

United States
The Williams Institute at UCLA School of Law, a sexual orientation law think tank, released a study in April 2011 estimating based on its research that 1.7 percent of American adults identify as gay or lesbian, while another 1.8 percent identify as bisexual. Drawing on 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. Of men, 2.2% identify as gay and an additional 1.4% as bisexual. Of women, 1.1% identify as lesbian and an additional 2.2% as bisexual.

These charts show a list of the top 10 US metropolitan areas with the highest LGB population in terms of numbers of total gay, lesbian and bisexual residents, based on estimates published in 2006 by the Williams Institute of the UCLA School of Law.

Top Ranked by Percent:

Top Ranked by Total Population: Major Metropolitan Areas by Total Population: