The English word “homosexual” is a derivative of two words, the Greek word homo, meaning “same,” and the Latin word sexus meaning “sex.” “Homosexual,” therefore, means same-sex activity, male with male, or female with female. In contemporary parlance male homosexuals are often called “gays,” and female homosexuals “lesbians.” The word “homosexual” is of relative modern origin, having been first...

Studies have used manipulated faces to test the preferences of heterosexual individuals for sexually dimorphic facial cues. In contrast to previous studies, which have generally excluded homosexual participants, we directly compared homosexual and heterosexual male and female preferences for manipulated sexual dimorphism in faces (homosexual males: n = 311; heterosexual males: n = 215; homosexu...

BACKGROUND The objective of the study was to estimate the prevalence of gonorrhoea and chlamydial infections and to determine sexual and demographic correlates for these sexually transmitted diseases (STD) among visitors of an STD clinic. METHODS In 1994, a cross-sectional study was carried out among 2984 consecutive visitors of the STD clinic of the University Hospital Rotterdam. RESULTS T...

BACKGROUND In the United Kingdom the incidence of sexually transmitted infections (STI) and risky sexual behaviours is increasing. The role of commercial sex in this trend is poorly understood. Little is known about the men who pay for sex. We examined the epidemiology of female commercial sex contacts reported by men in 1990 and 2000. METHODS National probability sample surveys of sexual att...

Background: In the United Kingdom the incidence of sexually transmitted infections (STI) and risky sexual behaviours is increasing. The role of commercial sex in this trend is poorly understood. Little is known about the men who pay for sex. We examined the epidemiology of female commercial sex contacts reported by men in 1990 and 2000. Methods: National probability sample surveys of sexual att...

Memories of sex-atypical behavior and interests in childhood usually differ between homosexual and heterosexual people. However, variation within these broad groups has not previously been explored in detail, especially among women. We utilized data from a postal survey of a nationwide sample of Australian adult twins (n = 4,901, age range: 19-52 years). Among men, 15.2% reported homosexual beh...

The prevalence of male same-gender sexual behavior in Mexico City in relation to HIV transmission was studied. A household probability survey of 8,068 adult men was conducted in 1992-93 using the Mexican National Health Survey sampling frame. The response rate was 59%. Differences between respondents and nonrespondents indicated no evidence for significant bias. A random subsample of 1,116 indi...

In adult male samples, homosexuality is associated with a preponderance of older brothers (i.e., the fraternal birth order effect). In several studies comparing gender dysphoric youth, who are likely to be homosexual in adulthood, to clinical or non-clinical control groups, the findings have been consistent with the fraternal birth order effect in males; however, less is known about unique sibs...

[T]he brains of both homosexual and heterosexual maleto-female transsexuals probably differ from the brains of typical heterosexual men, but in different ways. In homosexual male-to-female transsexuals, the difference does involve sex-dimorphic structures, and the nature of the difference is a shift in the female-typical direction. If there is any neuroanatomic intersexuality, it is in the homo...