What are some possible causes of gender dysphoria?

The answer to this question is complicated. Various theories and research evidence have been presented regarding the development of gender identity. Those theories have, with varying degrees of emphasis, pointed to biological, psychological or social factors as influencing or determining an individual’s gender identity. Current studies seem to evidence that a complex interaction of biological, psychological, and social factors all play a role, with the exact role they each play still being largely enigmatic.

Various theories and empirical studies have examined several facets of gender identity development, including what factors determine or influence gender identity, the malleability of gender identity, and the age at which gender identity is established. Research has also explored the nature of gender role, distinct from identity, which encompasses the behaviors, attitudes, and personality traits typically attributed to, expected from, or preferred in a male or female. One important distinction between gender identity and gender role is that gender role behavior—attributed masculine or feminine behavior—can to some extent be studied in animals, whereas gender identity and individual subjective sense of self, which tends to be unique to humans, cannot be studied in animals.

Research on gender identity also tends to focus along two distinct lines: normative development of gender identity and specific subpopulations, such as individuals with gender dysphoria or individuals who have a disorder of sex development (DSD). Studies of gender non-conformity or gender variance—gender role behaviors, interests and preferences that may be nonconforming to traditional or common gender roles but may not be associated with desires for sex reassignment—have typically been incorporated into studies of normative development (de Vries et al, 2013).

As previously noted, because of the complex interaction of biological, psychological, and social factors affecting identity development, the “biopsychosocial” model has been adopted as a framework for interpreting those factors. The biopsychosocial model has been adopted by many researchers as an alternative to the “medical model,” which is increasingly seen as reductionistic and unable to holistically incorporate the behavioral and psychosocial aspects of mental and even physical health and wellness. Various studies addressing gender role and gender identity development have explored biological factors such as brain differentiation via sex hormones (McCarthy, De Vries, & Forger, 2009; Hines, 2009), psychological factors such as those related Kohlberg’s (1966) three-stage gender constancy theory (Ruble, Martin, & Berenbaum, 2006) and Bem’s (1981) gender schema theory, and social factors such role-modeling as a means of transmitting values, attitudes, and patterns of thought and behavior (Bussey & Bandura, 1999).