WHEN we are born incomplete, we trust medicine to restore our identity. And so, over the past few decades, many boys born without a penis were converted surgically into females soon after birth — their diminished phalluses removed and reconstructed as vaginas; their parents encouraged to raise them as girls.

It was seen as the right thing to do in a world that could not countenance men without manhoods, and in a social climate that believed gender was gifted to us mainly by our upbringing.

The benevolent intentions of the past, however, have now turned into one of today’s most heartbreaking and complex medical dilemmas. A highly controversial American study of men born with cloacal exstrophy (CE), a rare, severe condition whose symptoms include phallic atresia (no penis), suggests that many of these “women” grow up to shun their adopted gender.

Of the study’s 16 genetic males (which means they possessed an XY chromosome pair), 14 had been reassigned as female — surgically, socially and legally. The parents of the remaining two had refused to permit reassignment (these two patients declared themselves to be male). Of the 14 “converts”, all had typically male hobbies and behaviours and only five truly felt female. Only one ever played with dolls.

Eight felt they were male — four before being told of their condition and four afterwards. All eight are attracted to women and now want penises; four of them are actually pursuing penile reconstruction. The remaining one of the 14 refused to discuss gender at all. The study, which appears in this month’s New England Journal of Medicine, has tremendous implications for the nature versus nurture debate: if boys raised to look and think as girls still view themselves as male, then the argument seems to sway heavily in favour of nature when it comes to sexual identity. Nurture cannot easily subvert nature, it seems, even when it is assisted by major surgery.

“We are challenging the conventional wisdom and urging doctors not to perform conversion surgery as routine,” said Dr John Gearhart, director of paediatric urology at Johns Hopkins Children’s Centre and co-author of the study.

“Rather, we suggest that they strongly consider counselling families to raise the children as males, and recommend penile reconstruction at a later age.

“Our findings suggest that children who are born genetically and hormonally male may identify themselves as male despite being raised as females and undergoing feminising genitoplasty at birth.”

However, Dr Polly Carmichael, a psychologist at Great Ormond Street Hospital, said that the hospital’s own study of CE patients who had been surgically altered to become female was much more favourable. “(Gearhart) is saying that these reassigned females are spontaneously saying they are male, but our cohort of ten patients do not have that experience,” she says.

The American study involved only 16 patients, and she says that participants might have presented themselves at clinic because they had gender problems which, in other words, possibly meant they were a self-selecting sample at the problematic end of the spectrum.

“The difficulty is that this is a very polarised argument about nature versus nurture. But we need to know that the evidence is very good before we move to a blanket policy of not reassigning gender.”

Gearhart’s paper, co-authored by William Reiner of Oklahoma University, could have ramifications in intersex conditions, which are situations where the gender of the child is unclear. In the past, the medical belief – first put forward by John Money in the 1950s – was that nurture determined gender and any corrective surgery should be done quickly after birth.

This crucial time was a window in which gender could be fixed, which would allow better parental bonding. On the basis that it is easier to hollow out a vagina than construct a functioning penis, the trend in the 1960s and 1970s was towards feminising surgery. And, of course, the child was never told the truth.