Dr. Money believed a person's gender identity was determined by an interaction between biological factors and upbringing. That theory was considered radical because most doctors attributed gender identity largely to biological factors.
``He really developed that entire field of study," said Dr. Gregory K. Lehne, a protege of Dr. Money and an assistant professor of medical psychology at Johns Hopkins. ``Without him, that whole field of study might not have existed."
Dr. Money advised parents on what sex they should bring up hermaphrodites -- people born with characteristics of both sexes -- to be. He also worked with people who were born with normal sex organs but did not identify with that gender.
``He pioneered the concepts related to this and the psychological aspects of sex reassignment," Lehne said.
Lehne said Dr. Money appeared to enjoy the controversy his work raised because it provoked people to think in different ways about gender.
Dr. Money was involved in a highly publicized case of a boy who was brought up as a girl after suffering a seared penis while being circumcised in 1966.
David Reimer was brought up as ``Brenda" after Dr. Money advised his parents to remove the rest of his male genitalia and recommended female hormone treatment.
Reimer was 15 when he learned his true identity and rejected further treatment as a girl. He committed suicide in 2004 at the age of 38 after failed investments drove him into poverty.
Lehne said Dr. Money did not talk publicly about the case and Hopkins said her uncle did so out of respect for the family.
``He had total sympathy and distress over the situation the family was in," she said.
Dr. Money was married but soon divorced in the 1950s. He had no children.
