Believing that gender identity was malleable within the first two years of life, Money advocated for the surgical "normalization" of the genitalia of intersex infants.

[2] Money advanced the use of more accurate terminology in sex research, coining the terms gender role and sexual orientation.

[7] A 1997 academic study criticized Money's work in many respects, particularly in regard to the involuntary sex-reassignment of the child David Reimer.

[10] Money believed that transgender people had an idée fixe, and established the Johns Hopkins Gender Identity Clinic in 1965.

Author Janet Frame attended some of Money's classes at the University of Otago, as part of her teacher training.

[6][28] According to a 1987 paper, he employed the drug Depo-Provera (medroxyprogesterone acetate) for use on sex offenders at Johns Hopkins beginning in 1966.

"[30] Colapinto speculates that Money's rationale for his treatment of the children was his belief that "childhood 'sexual rehearsal play' at thrusting movements and copulation" was important for a "healthy adult gender identity".

[10] Brian spoke about the therapy "only with the greatest emotional turmoil", and David was unwilling to speak about the details publicly.

[32] Soon after, Reimer went public with his story, and John Colapinto published a widely disseminated and influential account in Rolling Stone magazine in December 1997.

[40] However, intersex activists also criticized Money, stating that the unreported failure had led to the surgical reassignment of thousands of infants as a matter of policy.

[12] In one paper, Money described trans women as "devious, demanding and manipulative in their relationships with people on whom they are also dependent" and “possibly also incapable of love.”[43][44] Money believed that de-stereotyping sex roles might prevent people from wanting to transition, arguing “a tomboy-ish girl, prenatally androgenized, grows up to be a career-minded woman, not a transsexual who claims to need sex reassignment”.

Money screened adult patients for two years prior to granting them a medical transition, and argued that none regret the procedure as a result.

[47][48] John Money was a leading proponent of the idea that human sexual orientation develops through learning and gendered socialization.

[49] A 2016 academic review found that in seven total cases of boys surgically reassigned and raised as girls (due to botched circumcision or cloacal exstrophy), all were strongly attracted to women, not men, inconsistent with this learning theory of homosexuality.

In two 1983 case study publications, Money stated that pedophilia, among other chronophilias, could be characterized as combining "devotion, affection, and limerence", "comradeship with a touch of hero-worship" and ultimately as "harmless... in most instances".

"[53][54]Also in 1986, Money postulated the existence of multiple chronophilic forms of erotic age-roleplaying, or age impersonation, which he named "infantilism", "juvenilism", "adolescentilism", "gerontilism".

[1] Money introduced numerous definitions related to gender in journal articles in the 1950s, many of them as a result of his studies of intersex morphology.

According to Money's theory, sex-adjunctive differences are typified by the smaller size of females and their problems in moving around while nursing infants.

[citation needed] Sex-arbitrary differences are those that are purely conventional: for example, color selection (baby blue for boys, pink for girls).

"[55]He then defined gender role as; "all those things that a person says or does to disclose himself or herself as having the status of boy or man, girl or woman, respectively.

Gender role is appraised in relation to the following: general mannerisms, deportment and demeanor; play preferences and recreational interests; spontaneous topics of talk in unprompted conversation and casual comment; content of dreams, daydreams and fantasies; replies to oblique inquiries and projective tests; evidence of erotic practices, and, finally, the person's own replies to direct inquiry.

[56] In his book Gay, Straight and In-Between: The Sexology of Erotic Orientation, Money develops a conception of "bodymind".

In coining the term "bodymind", in this sense, Money wishes to move beyond these very ingrained principles of our folk or vernacular psychology.

Money also developed a view of "Concepts of Determinism" which, transcultural, transhistorical, and universal, all people have in common, sexologically or otherwise.

[58] These include pairbondage, troopbondage, abidance, ycleptance, foredoomance, with these coping strategies: adhibition (engagement), inhibition, explication.

Moreover, it confers the distinct advantage of having continuity and unity to what would otherwise be a highly disparate and varied field of research.

"It allows one to think developmentally or longitudinally, in terms of stages or experiences that are programmed serially, or hierarchically, or cybernetically (i.e. regulated by mutual feedback).

[60] The Law & Order: Special Victims Unit episode "Identity" (2005) was based on David and Brian Reimer's lives and their treatment by Money.