The 'biosocial approach' refers to theories that combine both biological and social explanations, such as Money and Ehrhardt's theory and social role theory. You can choose whether to discuss one or more theory.

Money and Ehrhardt’s biosocial theory suggest that social labelling and different treatment of boys and girls interact with biological factors (such as prenatal exposure to testosterone) to steer development. Unlike explanations that are purely biological or purely social, this theory was an attempt to integrate the influences of nature and nurture.

Money and Ehrhardt argued that the primary determiner of gender development is the sex of rearing, which is initially determined by biological factors. The child will be socialised based on this sex and their gender will develop based on how they are raised. Money and Ehrhardt predicted that if a genetic male is mislabelled as a girl and treated as a girl before the age of three, he will acquire the gender identity of a girl.

This theory, however, has been disputed by the case of David Reimer, who was genetically male but was raised as a girl (under Money's recommendation) after a botched circumcision. Despite being given hormone treatments in order to develop an outwardly female appearance, Reimer became isolated and depressed, and reverted back to being male immediately after finding out his true sex. This conflicts with Money's claims that genetic sex is more important to gender development than the sex of rearing.

This outcome has also been supported by further research. Reiner & Gearhart studied 16 biological males born with almost no penis. Of the 14 who were raised female, 8 re-assigned themselves as male by the age of 16. This high rate suggests that biological factors have a more important