Diamond, who works at the John A. Burns School of Medicine, and Dr. H. Keith Sigmundson of the Department of Psychiatric Services, Ministry of Health, Victoria, British Columbia, followed a case of a twin boy whose sex was altered in the early 1970s.
Their findings contest medical literature citing the case as an example of successful sex reassignment for infants. Their report appears in the March issue of "Archives of Pediatrics & Adolescent Medicine" and was released today by the American Medical Association.
Diamond says pediatric textbooks advise "sex reassignment" at birth if genitals are ambiguous or severely traumatized - a standard practice he has challenged for more than 30 years.
"You can't tell sex by looking at genitals," he says. "You have to look at the brain."
Diamond, in an interview, said more than some cases occur every year in Hawaii similar to the boy he calls John.
John's sexual identity crisis started when his penis was destroyed accidentally during a medical procedure at 8 months of age, Diamond said.
"The guru at that time was John Money who was saying people are born sexually neutral and society makes them into boys or girls," he said. Money was at the Johns Hopkins Hospital in Baltimore where John's surgery was done.
The decision was based on the theory that it's easier to make a good vagina than a good penis; a child's identity will reflect upbringing, and an inadequate penis would be sexually devastating, Diamond and Sigmundson reported.
"I don't have 100 percent of the answers," Diamond said. "All I want is for people to think about it ... Some physicians consider these conditions medical emergencies (at birth) so a kid has to be reconstructed before leaving the hospital."
He maintains, however, that "these are cosmetic decisions" best left to the person affected and not made by doctors and parents.
Diamond and Sigmundson said that while John wants to remain anonymous, he wants people to know what happened to him.
As they described it:
After the reconstructive surgery, the child was given a girl's name and female steroids. The mother was told to treat the child as a girl and dress the child as a girl. She said it was a disaster. "I put this beautiful little dress on him ... and he (immediately tried) to rip it off," she told doctors.
The child thought she was a freak because she liked being with guys and climbing trees. Girls teased her because she had wide shoulders and looked like a boy in girls' clothes.
She rebelled against taking hormones and had suicidal thoughts.
When she was 14, she decided to live as a male, against everybody's advice, Diamond said. John asked for male hormone shots, a mastectomy and penis construction. He adjusted well, the researchers said.
Dr. H. Sorrell Waxman, at Kapiolani Medical Center for Women and Children, said he's had only about three such cases. "This is not done arbitrarily in any way, shape or form," he stressed.
"Most of the time there's enough genitalia there that you can correct a patient to whatever chromosomes tell you is there," he said. "Occasionally, it is not enough and we have to make anatomical changes."
He said, "It's very difficult to make a boy out of a girl, regardless what anybody tells you. You end up with an inappropriate male." And in most cases involving anatomical changes, he added, "You have an incomplete male or female, regardless of surgery and hormone treatment."
Waxman said there is some evidence that tends to support University of Hawaii researcher Milton Diamond's theory that the brain determines sex, not genitals. "But so many psychological factors enter into it ... you can find cases backing up any type of theory."
He said he doesn't subscribe totally to any theory but bases his decisions on circumstances of each case.
Lt. Col. David Crudo at Tripler Army Medical Center said, "Most textbooks say our sexual identity isn't really established before 15 months of age, so if it takes a couple months to decide, yes, chromosomally it's male but it would be better off raised as a female, we do sex reversals."
When a child is born with ambiguous genitals and doctors can't tell whether it's a boy or girl, he said, "You tell the parents something happened and you try to figure out what the sex is or what the proper sex should be for the baby."
Crudo recalled a baby eight to nine years ago at Tripler who wasn't expected to function as a male because of a deformed penis due to defects in embryology.
The doctors transformed the baby into a female.