- Sexual orientation, homosexuality and bisexuality. American Psychological Association. [August 10, 2013]. （原始内容存档于August 8, 2013）.
- APA California Amicus Brief (PDF). Courtinfo.ca.gov. [2013-10-11].
- Bailey, J. Michael; Vasey, Paul; Diamond, Lisa; Breedlove, S. Marc; Vilain, Eric; Epprecht, Marc. Sexual Orientation, Controversy, and Science. Psychological Science in the Public Interest. 2016, 17 (2): 45–101. PMID 27113562. doi:10.1177/1529100616637616.
- Human sexual activity - Sociosexual activity. Encyclopedia Britannica. [2019-12-21] （英语）.
- Frankowski BL; American Academy of Pediatrics Committee on Adolescence. Sexual orientation and adolescents. Pediatrics. June 2004, 113 (6): 1827–32. PMID 15173519. doi:10.1542/peds.113.6.1827.
- Lamanna, Mary Ann; Riedmann, Agnes; Stewart, Susan D. Marriages, Families, and Relationships: Making Choices in a Diverse Society. Cengage Learning. 2014: 82 [February 11, 2016]. ISBN 978-1-305-17689-8.
The reason some individuals develop a gay sexual identity has not been definitively established – nor do we yet understand the development of heterosexuality. The American Psychological Association (APA) takes the position that a variety of factors impact a person's sexuality. The most recent literature from the APA says that sexual orientation is not a choice that can be changed at will, and that sexual orientation is most likely the result of a complex interaction of environmental, cognitive and biological factors...is shaped at an early age...[and evidence suggests] biological, including genetic or inborn hormonal factors, play a significant role in a person's sexuality (American Psychological Association 2010).
- Gail Wiscarz Stuart. Principles and Practice of Psychiatric Nursing. Elsevier Health Sciences. 2014: 502 [February 11, 2016]. ISBN 978-0-323-29412-6.
No conclusive evidence supports any one specific cause of homosexuality; however, most researchers agree that biological and social factors influence the development of sexual orientation.
- Gloria Kersey-Matusiak. Delivering Culturally Competent Nursing Care. Springer Publishing Company. 2012: 169 [February 10, 2016]. ISBN 978-0-8261-9381-0.
Most health and mental health organizations do not view sexual orientation as a 'choice.'
- LeVay, Simon. Gay, Straight, and the Reason Why: The Science of Sexual Orientation. Oxford University Press. 2017. ISBN 9780199752966.
- Balthazart, Jacques. The Biology of Homosexuality. Oxford University Press. 2012. ISBN 9780199838820.
- Laumann, E. O., Gagnon, J. H., Michael, R. T., & Michaels, S. (1994). The social organization of sexuality: Sexual practices in the United States. Chicago: University of Chicago Press.[页码请求]
- Wellings, K., Field, J., Johnson, A., & Wadsworth, J. (1994). Sexual behavior in Britain: The national survey of sexual attitudes and lifestyles. London, UK: Penguin Books.[页码请求]
- Bogaert AF. The prevalence of male homosexuality: the effect of fraternal birth order and variations in family size. Journal of Theoretical Biology. September 2004, 230 (1): 33–7. PMID 15275997. doi:10.1016/j.jtbi.2004.04.035. Bogaert argues that: "The prevalence of male homosexuality is debated. One widely reported early estimate was 10% (e.g., Marmor, 1980; Voeller, 1990). Some recent data provided support for this estimate (Bagley and Tremblay, 1998), but most recent large national samples suggest that the prevalence of male homosexuality in modern western societies, including the United States, is lower than this early estimate (e.g., 1–2% in Billy et al., 1993; 2–3% in Laumann et al., 1994; 6% in Sell et al., 1995; 1–3% in Wellings et al., 1994). It is of note, however, that homosexuality is defined in different ways in these studies. For example, some use same-sex behavior and not same-sex attraction as the operational definition of homosexuality (e.g., Billy et al., 1993); many sex researchers (e.g., Bailey et al., 2000; Bogaert, 2003; Money, 1988; Zucker and Bradley, 1995) now emphasize attraction over overt behavior in conceptualizing sexual orientation." (p. 33) Also: "...the prevalence of male homosexuality (in particular, same-sex attraction) varies over time and across societies (and hence is a "moving target") in part because of two effects: (1) variations in fertility rate or family size; and (2) the fraternal birth order effect. Thus, even if accurately measured in one country at one time, the rate of male homosexuality is subject to change and is not generalizable over time or across societies." (p. 33)
- Hope, Debra A (编). Contemporary Perspectives on Lesbian, Gay, and Bisexual Identities. Nebraska Symposium on Motivation 54. 2009. ISBN 978-0-387-09555-4. doi:10.1007/978-0-387-09556-1.
- McConaghy et al., 2006
- Sexual Behavior Levels Compared in Studies In Britain and France. nytimes.com. 8 December 1992.