What happens, medically and socially, when a person apparently changes sex? Roberta Cowell, one of the first of such cases, tells of the unhappiness and over-compensation of her first 30 years, and what the change has meant. Already, as a schoolboy, she was self-conscious about her wide hips, white skin, and abnormal genitals, and tried to make up for it by being over-aggressive, one of "the boys." Later, she became a pilot and motor racing driver, but increasingly she ran into medical and social difficulties in being accepted as a man – she used to wear a tight elastic bandage round her chest to hold in her breasts.

In the end she was advised by her doctors that she was a woman. In 1951 she was legally re-registered on her birth certificate as female, and a year later, having started to live as a woman, she underwent a series of operations. Birth certificates can only be changed in this way if doctors will testify that a mistake was made at birth.

In 1954 Roberta Cowell sold the story to "Picture Post." The publicity brought in a flood of requests for help with sexual problems. With the less dramatic queries she finds she can help, and she now spends much of her time on it. "People will tell me the most extraordinary things."

Many requests for help, however, come from homosexual men. These she passes on to her partner, a psychiatrist, since she feels unable to cope impartially. "It is distressing that so many people think they can change sex just like that. Sex is fixed at conception and cannot be changed."

Perhaps the change is usually from male to female because, as Roberta Cowell thinks, it is much easier to live as a woman than as a man. "A man must prove his masculinity and go on proving it; a woman just has to be." She also finds that people are much nicer, kinder and more friendly to women than to men. On the other hand it is harder she thinks for a woman to work and make a living.

Undoubtedly, those who in every social sense have "changed" suffer greatly at the hands of the law and bureaucracy. It comes right down to which public lavatory you use. It seems more humane to treat this tiny minority who live in a sexual limbo with tolerance and understanding, and not with mirth, cynicism or punishment. But while life stories of sex change claimants sell for such alluring sums perhaps such humanity is difficult. And the subject will continue to be saleable while it is so veiled in mystery.

Auriol Stevens

These archive extracts are compiled by members of the Guardian's research and information department. Email: research.department@guardian.co.uk