Re: Availability of kdb

From: Chris Ricker (chris.ricker@genetics.utah.edu)
Date: Thu Sep 07 2000 - 09:49:53 EST


On Wed, 6 Sep 2000, Jeff V. Merkey wrote:

> I have no axe to grind, but I do have a different view. I'm the 1 in 30
> million men born with an extra Y chromosone (a double YY), so you are
> pertially right there. DOuble YY males have a different brain structure
> -- the lymbic system in my brain is so electrically active, it qualifies
> as a third brain. Normal humans have two brains, left and right. Like
> most double YY's I have three, left, right, lymbic. Fortunately for me,
> my frontal lobes are normal and do not exhibit the wiring problems that
> afflict 60% of double YY's, such as an uncontrollable urge to take an
> axe and chop someone to pieces because they pissed me off.

<putting on my human geneticist hat>

Not that any of this has anything to do with Linux kernel development, but
you really should do a bit more background reading on 47,XYY. Incidence is
much, much higher than you claim. Frequency estimates vary slightly with
the study, of course, but it's usually somewhere around 1 in 1000 live male
births (1 in 843 reported in Birth Defects 26:209-223, for example, and
similar results in Prenatal Diagnosis 17:363-368. The *lowest* frequency
I've ever seen reported was ~ 1/1250).

Similarly, no scientific study I've ever seen has substantiated any of that
nonsense about "lymbic wiring" or three brains. [1] There's a very small
correlation between 47,XYY and: tallness, slightly reduced IQ,
hyperactivity, ADD, and learning disabilities. AFAIK, there's no
demonstrated physiological difference between 46,XY males (ie, "normal") and
47,XYY; average testosterone levels are the same in both, for example (AACE
report, 1998). If you actually know of scientific studies substantiating
the above claim of a physiological difference in the brain or any other
physiological differences, I'd really appreciate references. Ditto for the
list of individuals you claim had 47,XYY -- the only "famous" person I know
of with any connection to the condition was Richard Speck, who falsely
claimed to be 47,XYY in an attempt to get leniency for his murders. I'm
curious about your references because it's a condition which is quite
common, but which is very rarely diagnosed precisely because it usually has
no effect....

Sorry about responding to this on linux-kernel instead of privately, but
47,XYY is a condition for which most popular "knowledge" is both wrong, and
quite persistent in its popularity and acceptance; furthermore, this
incorrect "knowledge" is often detrimental to those with the condition (ie,
Psychological Bulletin 78:209-233). Historically, it was popularly thought
that 47,XYY was a condition leading to hyperaggression, criminal behavior,
etc., and so those with 47,XYY were often treated accordingly. The
scientific reality is far more boring; most males with 47,XYY -- like most
males with 46,XY -- are as normal as males ever are, and should be treated
accordingly ;-).

later,
chris

[1] I suspect you're conflating two very different conditions, Klinefelter
syndrome (47,XXY) and 47,XYY. Some studies (ie, J Neurol Neurosurg
Psychiatry 66:628-32) have demonstrated neurological differences for
subjects with Klinefelter syndrome, but they have simultaneously
demonstrated that neurological structures in 47,XYY subjects are no
different than in age-matched 46,XY controls.

-- 
Chris Ricker                                               kaboom@gatech.edu
                                              chris.ricker@genetics.utah.edu

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