http://etransgender.com/viewtopic.php?f=2&t=331 :

New research provides more evidence that boys will be boys -- even if
they're raised as girls.

Eight of 14 sexually malformed children who grew up as females later
declared themselves to be male, a new study says.

All the children were born with a defect that left them without normal
male genitals. Surgeons removed their testes, which were inside their
bodies, and their parents chose to consider them to be girls.

Experts say the findings support the controversial notion that
environment alone doesn't determine whether humans consider themselves
to be males or females. "It just shows that nurture is not able to
overcome nature in many cases," says Dr. Eric Vilain, who studies so-
called "intersex" children at the University of California at Los
Angeles.

An estimated 1 percent of babies are born with malformed genitals,
usually minor problems that can be fixed surgically, such as
undescended testicles or malformed openings of the urethra. But some
have a more serious problem -- severely malformed or so-called
"ambiguous" genitalia. The gender of the child may not be obvious; in
some cases, the babies appear to be both male and female.

In past decades, psychologists tried to "fix" the children by
assigning them a gender, even if it didn't match the gender determined
by their chromosomes. Surgeons then operated on their genitals to make
them match the assigned gender.

Many intersex children went on to rebel against their "gender
assignments." In a famous case documented in the book As Nature Made
Him: The Boy Who Was Raised as a Girl, a Canadian boy who suffered a
botched circumcision was operated upon and raised as a girl. He
suffered through a tortured adolescence and later chose to live as a
man and get married.

In the new study, researchers talked to 16 children, aged 5 to 16, who
were born with a defect known as cloacal exstrophy that left them
without normal penises. All the children are genetically male.

The findings of the study, which followed some of the children for
years, appear in the Jan. 22 issue of the New England Journal of
Medicine.

Two children in the study were raised as boys and continued to think
of themselves as males. The other 14 had surgeries to remove their
testes and create female genitalia. They were raised as girls, and
even their birth certificates reflected their new genders.

Eight of the 14 later declared themselves to be male, and six of them
said they wanted prosthetic penises. Even the children who consider
themselves to be females appeared to have some male traits. All said
they have trouble fitting in with other girls (although none said the
same about boys), and they reported little interest in playing with
dolls or playing house.

The findings suggest gender identity "looks to be pretty much hard-
wired" into the brain, says study co-author Dr. William G. Reiner, a
pediatric urologist at University of Oklahoma Health Sciences Center.
But he adds that environment -- the way children are raised -- plays a
role, too. "Nature interacts with nurture constantly in ways that are
complex and difficult to understand. They constantly change each
other."

So what should be done with babies with the defect described in this
study? "If there's a question about the child's sexual identity, we
need to be very careful," Reiner says.

While it may make sense to choose a gender for a such a child early in
his or her life, "how are you or I going to know what they want until
they tell us?"

Dr. Melvin Grumbach, a pediatrician and professor emeritus at the
University of California at San Francisco, also supports caution and
patience when it comes to untangling questions of gender in these
children. "It is not one size fits all," he says.