RESEARCH QUESTION
Are there sexual orientation differences in gambling?

PURPOSE
To date, virtually no data has been reported describing the incidence of regular or pathological gambling between homosexual males and females. The aim of the present study was to determine whether sexual orientation differences in gambling exist that parallel those for sex (i.e., the idea that male homosexuality arises from prenatal brain feminization and that female homosexuality arises from prenatal brain masculinisation).

HYPOTHESIS
Male homosexuals would be more similar to female heterosexuals than male heterosexuals and female homosexuals would be more similar to male heterosexuals than female heterosexuals with respect to gambling frequency.

PARTICIPANTS
Data from 10,598 Kinsey Institute for Sex Research case histories (57% males) were used in the present research. Individuals were classified as homosexual men (n = 935), heterosexual men (n = 4,187), homosexual women (n = 275), or heterosexual women (n = 5,201).

PROCEDURE
Staff members of The Kinsey Institute for Research in Sex, Gender, and Reproduction collected case histories via survey interviews between 1938 and 1963. The survey measures of most relevance to the present study were those pertaining to demographics, gambling frequency, and sexual orientation.

MAIN OUTCOME MEASURES
The demographic variables that were examined included: age, race/ethnicity, number of years of education, and parental socioeconomic status (because many respondents were still in school when they were interviewed). With respect to sexual orientation, men and women were classified as homosexual if they reported ‘‘extensive’’ homosexual experience (i.e., more than 20 same-sex sexual partners or more than 50 homosexual experiences with one or more partners). Men and women were classified as heterosexual if they met two criteria: they reported ‘‘no’’ or ‘‘rare’’ homosexual experience (i.e., 1 same-sex sexual partner or 1–5 homosexual experiences), and they did not respond that they experienced ‘‘much’’ or ‘‘some’’ sexual arousal to questions about sexual arousal from seeing or thinking of members of their own sex. Gambling frequency was assessed via two questions. The first asked whether participants gambled on cards, races, or any game. If participants responded “yes” to that question, they were then asked whether, in terms of money, they would call themselves a light, moderate, or heavy gambler. The answers to the two questions were combined into one item, referred to as current frequency of gambling, to provide information regarding the importance of gambling in each participant’s life. The response options for the item were: “none,” “rare,” “little,” “some,” and “much.”

KEY RESULTS
An association was found between gambling frequency and sex such that men gambled more frequently than women.  An association was also found between gambling and sexual orientation such that a greater number of homosexuals engaged in some gambling than did heterosexuals. The association between gambling and male sexual orientation arose due to the presence of relatively more homosexual than heterosexual men in the “none” category. Thus, there was an excess of homosexual men who did not gamble, relative to heterosexual men. The association between gambling and female sexual orientation arose due to the presence of relatively more homosexual women than heterosexual women in the “much” category. Thus, there was an excess of homosexual women who gambled a great deal, relative to heterosexual women. Homosexual men were found to gamble more than heterosexual women, homosexual men and homosexual women were found to gamble to the same degree, heterosexual men were found to gamble more than homosexual women, and heterosexual men were found to gamble more than heterosexual women. These four differences, combined with the sex and sexual orientation differences, formed a perfectly transitive ordering of gambling frequency fully consistent with the hypothesis posed: heterosexual men gambled more than homosexual men who gambled the same as homosexual women who gambled more than heterosexual women.

LIMITATIONS
The measure of gambling frequency used consisted of a single item, the reliability of which may be questioned. Further, definitions were not provided for the answer options (i.e., “rare,” “little,” “some,” and “much”) for the gambling frequency item. Such definitions could have assisted participants in distinguishing among the magnitudes implied by the response options.

CONCLUSIONS
Overall homosexual men reported gambling less frequently than heterosexual men, while homosexual women reported gambling more frequently than heterosexual women. The male difference was found at lower levels of gambling, whereas the female difference was found at higher levels of gambling. Men also reported gambling more frequently than women. Given that the sexual orientation findings for gambling resemble the findings for alcohol and tobacco use, perhaps gambling should be seen within a broader context of sexually dimorphic addictive/externalizing behaviors.