A surprising number of readers of my Friday column seem to think that
“congenital” is a synonym for “genetic.” Not so. Here is the
Merriam-Webster’s Third entry for “congenital”:
1 : existing at or dating from birth congenital idiocy congenital malformations : belonging to or associated with from birth : INNATE
congenital good health : constituting an essential characteristic :
INHERENT the congenital State Department fear of newsmen A.H.Vandenberg
1951 : from birth or by nature *a congenital liar*
2 : acquired during development in the uterus and not through heredity –
compare ACQUIRED, FAMILIAL, HEREDITARY
synonyms see INNATE
Note that in the second meaning, “congenital” is actually *opposed* to
“hereditary.”
The evidence that homosexual orientation is, in most cases, congenital, is
rather strong, though still disputed by respectable authorities. The
evidence that there is some genetic component is less strong, and more
disputed — though on my own fragmentary and non-systematic reading, it
seems to me probable that there *is* some genetic component to homosexual
orientation. (Homosexual *acts*, of course, are products of the human
will.)
If indeed there is some genetic component to homosexual orientation, that is
an evolutionary conundrum, since obviously an amatory preference for one’s
own sex carries a “negative Darwinian load.” (Sorry about the jargon, but I
think the meaning is clear.) That does not by any means “disprove
Darwinism,” though, as a couple of readers crowed. It is possible to think
of Darwinian explanations for a genetic component, and a great deal of
intellectual effort has gone into this over the past 20 years or so. Early
models — the “kind gay uncle” theory is best known (the idea being that
non-reproducing but caring members of the tribe add a *group* benefit in
child-raising that outweighs the *individual* Darwinian negative) — could
not be made to work mathematically, and are not now taken very seriously.
Other possibilities have been thought up, though, of which the most
interesting is the disease theory. Here the idea (if I have understood it
correctly) is that a genetic mutation that protects us against some horrid
disease turned up, with the slight downside that it pre-disposes to
homosexuality in some small minority of gene-bearers, presumably by acting
in concert with certain other genes that some people have and some don’t.
The Darwinian positive (protection against that disease, whatever it is)
sufficiently outweighs the negative (1 to 4 percent of the population are
non-reproducing homosexuals) to keep the gene in play. Sickle-cell anemia
(a by-product of a genetic defense against malaria) offers a parallel. The
evolutionary mathematics of this *can* be made to work, though until we get
deeper into the genetic code it has to be regarded as speculative.
I will say again what I have said before on this site: The scientific
understanding of human nature is right now just about where chemistry was in
1700, or electricity in 1800, or the atom in 1900. This is going to be a
very interesting century. AND the results we are starting to get suggest
that human nature is much more like what conservatives have always said,
than like what liberals have told us.