Dr. Evelyn Hooker (September 2, 1907 – November 18, 1996) was an American psychologist most notable for her 1957 paper “The Adjustment of the Male Overt Homosexual” in which she administered several psychological tests to groups of self-identified male homosexuals and heterosexuals and asked experts to identify the homosexuals and rate their mental health. The experiment, which other researchers subsequently repeated, argues that homosexuality is not a mental disorder, as there was no detectable difference between homosexual and heterosexual men in terms of mental adjustment.

Her work argued that a false correlation between homosexuality and mental illness had formed the basis of classifying homosexuality as a mental disorder by studying only a sample group that contained homosexual men with a history of treatment for mental illness. This was of critical to the argument that homosexuality is not developmentally inferior to heterosexuality. Her demonstration that it is not an illness led the way to the eventual removal of homosexuality from the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders.

In the 1940s Dr. Hooker became friends with a student who confided in her that he was gay. They became friends, and she was eventually introduced to his circle of homosexual friends, including a writer and poet who challenged Evelyn to scientifically study and conduct research on homosexuals. Evelyn was intrigued by the idea, persuaded by her experience with social rejection as a child, the racial and political persecution she witnessed in her travels, and the discrimination she faced in her professional life, for being a woman.

Hooker gathered a sample of 30 heterosexual men and 30 homosexual men and paired them based on equivalent IQ, age, and education. Hooker ensured that none of the participants from either group had previously been seen for psychological help; had been in disciplinary barracks in the Armed Services; served time in prison; showed evidence of considerable disturbance; nor were ever in therapy. She had to use her home to conduct the interview to protect the participants’ anonymity.

Hooker used three psychological tests for her study: the TAT, the Make-a-Picture-Story test (MAPS test), and the Rorschach inkblot test. The Rorschach was used due to the belief of clinicians, at the time, that it was the best method for diagnosing homosexuality. Deciding to leave the interpretation of her results to others, to avoid any possible bias, Hooker presented a team of three expert evaluators with 60 unmarked psychological profiles:

• Bruno Klopfer, an expert on Rorschach tests, attempted to identify the sexual orientation of the participants through their results of their tests. His ability to differentiate between the two groups was no better than chance.
• Edwin Shneidman, creator of the MAPS test, also analyzed the 60 profiles. It took him six months and he, too, found that both groups were highly similar in psychological make-up.
• Dr. Mortimer Mayer, who was certain he would be able to tell the two groups apart, went through the process twice, but was unable to accurately determine the sexualities of the participants.

The three evaluators concluded that, in terms of adjustment, there were no differences between the members of each group.

In 1956, Hooker presented the results of her research in a paper at the American Psychological Association’s convention in Chicago. The NIMH was so impressed with the evidence Hooker found they granted her the NIMH Research Career Award in 1961 to continue her work.

Hooker was invited to lecture in Europe and, in 1967, the director of the National Institute of Mental Health (NIMH) asked her to produce a report on what the institution should do about homosexual men. Her report was published by a magazine, without authorization, in 1970. The report recommended the decriminalization of homosexuality and the provision of similar rights to both homosexual and heterosexual people.

Hooker retired from her research at UCLA in 1970 at the age of 63 and started a private practice in Santa Monica. Most of her clients were gay men and lesbians. Her studies contributed to a change in the attitudes of the psychological community toward homosexuality and to the American Psychiatric Association’s decision to remove homosexuality from its handbook of disorders in 1973. This in turn helped change the attitude of society at large.

In her later life she would be awarded with the Distinguished Contribution in the Public Interest Award. The University of Chicago opened the Evelyn Hooker Center for Gay and Lesbian Studies in her honor. She was also the subject of the 1992 Academy Award–nominated film “Changing Our Minds: The Story of Dr. Evelyn Hooker”.

Hooker died at her home in Santa Monica, California, in 1996, at the age of 89.