Heterosexuality Humans 8 Male 8 heterosexuality 8 human 8 male 8 Female 7 female 7 sexual and gender minority 6 sexual behavior 6 Adult 5 Sexual Behavior 5 adult 5 Homosexuality, Male 4 Middle Aged 4 male homosexuality 4 middle aged 4 psychology 4 Adolescent 3 Article 3 HIV Infections 3 Homosexuality, Female 3 Human immunodeficiency virus infection 3 Sexual and Gender Minorities 3 Surveys and Questionnaires 3 adolescent 3 article 3 bisexuality 3 lesbianism 3 major clinical study 3