Dr. John Money, a well-known psychologist and sex researcher who coined the terms “gender identity”and “gender role” and whose theories expanded on the concept of gender, died Friday in Towson, Md. He was 84.

Money, a professor of medical psychology at Johns Hopkins University, believed a person’s gender identity was determined by an interaction between biological factors and upbringing. That represented a break from past thinking, in which gender identity was largely believed to be caused only by biological factors.

Money gave advice to parents to help them decide what sex they should raise hermaphrodites to be, and also worked with people who were born with normal sex organs but did not identify with the gender they had been raised to be. In 1965, he worked with the surgeon who performed the first sex-change operation at Johns Hopkins.

Money also was a pioneer in hormonal treatment to improve the self-control of sex offenders.

Money’s parental advice seemed to go awry in the case of David Reimer, a Canadian who was raised as a girl after a botched circumcision. When Reimer was 15, he learned about the mishap and his true sexual identity from his father. He then rejected further treatment as a girl, but committed suicide in 2004 at the age of 38 after failed investments drove him into poverty.

At the end of his career, Money developed the concept of lovemaps, which incorporate the diversity of human sexuality that each individual has encoded in his or her brain.