He received the Magnus Hirschfeld Medal in 2002 from the German Society for Social-Scientific Sexuality Research.
He was one of the first scientists to study the psychology of sexual fluidity and how the societal constructs of "gender" affect an individual.
For him, gender included not only one's status as a man or a woman, but was also a matter of personal recognition, social assignment, or legal determination; not only on the basis of one's genitalia but also on the basis of somatic and behavioral criteria that go beyond genital differences.
In 1972, Money presented his theories in Man & Woman, Boy & Girl, a college-level, mainstream textbook.
Money introduced numerous definitions related to gender in journal articles in the 1950s, many of them as a result of his studies of Hermaphroditism.
Money's definition of gender is based on his understanding of sex differences among human beings.