Acquired homosexuality is the idea that homosexuality can be spread, either through sexual seduction or recruitment by homosexuals,^[1] or through exposure to media depicting homosexuality.^[2][3] According to this belief, any child or young person could become homosexual if exposed to it; conversely, through conversion therapy, a homosexual person could be made straight.^[4]

It has been suggested that this article be merged with Homosexual seduction. (Discuss) Proposed since March 2024.

Although there is not yet complete understanding of the causes of sexual orientation, the evidence supporting biological causes is much stronger than that supporting social factors, and there is little or no evidence supporting the theory that homosexuality can be acquired through sexual contact with homosexual adults. In contrast, there is evidence that homosexual attractions precede behavior, usually by a few years, in most cases. Bailey et al. state, "a belief in the recruitment hypothesis has often been associated with strongly negative attitudes toward homosexual people", and those who make this argument generally do not explain an empirical basis for this belief.^[1]

In her book Epistemology of the Closet, Eve Kosofsky Sedgwick distinguishes between the minoritizing and universalizing view of sexual orientation; according to the former view, homosexuality is a property of a relatively stable minority, while according to latter view, anyone can potentially engage in homosexuality.^[5] The original view was a universalizing one, whereas the ideas about homosexuality being a fixed sexual preference developed in the second half of the nineteenth century, proposed independently by gay activist Karl Heinrich Ulrichs, French psychiatrist Claude-François Michéa, and German physician Johann Ludwig Casper.^[6][7] In the early twentieth century, German sexual science showed that many adolescent boys practiced homosexual behaviors (such as kisses, hugs, caresses, and mutual masturbation) for a few years; healthy development was considered to consist of abandoning them when they were older. It was believed that the incidence of adolescent homosexual behavior had increased after World War I, one of the most popular explanations being that adult homosexual men (either in person or via gay-oriented publications) had caused the increase. This theory was popular among the general public, but also among psychologists and psychiatrists who treated youth.^[8]

Based on the theories of Karl Bonhoeffer and Emil Kraepelin,^[9] the Nazis believed that homosexuals seduced young men and infected them with homosexuality, permanently changing the sexual orientation and preventing the youth from becoming fathers. Rhetoric described homosexuality as a contagious disease,^[10] but not in the medical sense. Rather, homosexuality was a disease of the Volkskörper (national body), a metaphor for the desired national or racial community (Volksgemeinschaft). According to Nazi ideology, individuals' lives were to be subordinated to the Volkskörper like cells in the human body. Homosexuality was seen as a virus or cancer in the Volkskörper because it was seen as a threat to the German nation.^[11] The SS newspaper Das Schwarze Korps argued that forty thousand homosexuals were capable of "poisoning" two million men if left to roam free.^[12]

Belief that homosexuality was acquired through sexual contact was one of the ideas fueling the persecution of homosexuals in Nazi Germany. Because of the all-male organizations for boys and young men, such as the Hitler Youth, SA, and SS, the Nazis were afraid that homosexuality would spread rapidly in the absence of a harsh crackdown. The murders of the Night of Long Knives were justified by claims of crushing alleged homosexual cliques in the SA. Adolf Hitler stated afterwards that "every mother should be able to send her son to the SA, Party, or Hitler Youth without fear that he would be ethically or morally corrupted there".^[13]

A 2018 study in the United States found that exposing participants to scientific information about the causes of homosexuality did not change support for LGBT rights.^[14]

In the Weimar Republic, there was a widespread belief among Germans that homosexuality was not inborn but instead acquired.^[23] In Russia, a survey^[when?] found that 61 percent of people believe homosexuality is acquired, while 25 percent believe it is innate.^[2]

• Rapid onset gender dysphoria controversy
• Situational homosexuality