DOCTOR'S VIEW ARCHIVE
What ARE Little Boys & Girls Made Of?
JACKSONVILLE, FLORIDA-"What are little boys
made of? Snips and snails, and puppy dogs' tails; That's what
little boys are made of." according to the old nursery rhyme.
The next verse, of course, addresses the parallel question: "What
are little girls made of? Sugar and spice, and everything nice;
That's what little girls are made of."
The behavioral differences between boys and girls
continue to be a matter of common wisdom. For example, there was
a front-page article in The New York Times on June 15 about the
children of Robert F. ("Bobby") Kennedy. The reporter
Deborah Sontag noted that, among Bobby's 11 children: "It
was accepted that the boys had more problems than the girls, because
as Mrs. Kennedy Townsend (the eldest of Bobby's offspring) said,
'boys in general get in trouble more.'"
Do boys "get in trouble more?" Even more
basically, do boys and girls engage in different behaviors? If
so, why? Is it all learned through our experiences (environmental)?
Or, do our genes play a role, perhaps in pre-programming our behavior?
What may be truly different between boys' and girls'
behaviors may not have to with boys' snips and snails and puppy
dogs' tails or with girls' sugar and spice levels. Instead, it
may have to do with differences between their X chromosomes.
That is what is proposed in a provocative study published
this week in the eminent British journal Nature
(1997;volume 387, page 705). The paper is entitled "Evidence
from Turner's syndrome of an imprinted X-linked locus affecting
Boys (XY) always receive their single X chromosome
from their mother while girls (XX) receive an X from their mother
and an X from their father. As far as X chromosomes go, what separates
boys from girls is not only that girls have two X chromosomes
but that only girls have an X chromosome from their father (a