The following is a "letter to the editor," published May 14, 1995 in "The
Morning News of Northwest Arkansas." It is verbatim; I see no need to
paraphrase. I hope this group finds it interesting.
"The editorial of April 29, page 18A, 'The Decline in Reading,'
had bad news and good news. The bad news is that 'reading proficiency
[is] down in virtually 40 states ...and significantly down in 10.' The
good news is 'that math scores are on the rise.' The editorial says that
'educators almost unanimously agree that' teachers aren't asking enough
of their students. Their conclusion doesn't make sense; it would take a
major conspiracy to cause a nation-wide drop in reading skills.
Ironically, a rise in math scores, along with a decline in reading
scores, may both signal something else is happening, perhaps beyond the
reach of the best teachers.
It is generally accepted that the two sides of the brain
(cerebral hemispheres) interact but basically perform different
functions. The things we call reading and writing are usually controlled
by the left half, mathematical things and spatial abilities are usually
located in the right half. Because of this divergence in function, boys
are, generally, but not always, better in math than girls. My work
suggests a reason for this that is directly connected to the changin
reading and math scores.
The left hemisphrere finishes growth a little after the right.
My work suggests brain growth is particularly dependent on the hormone,
DHEA. (DHEA in extremely small quantities stimulates formation and
growth of the brain cells primarily used in thinking, neurons.)
Therefore, the left hemisphere depends on a continued supply of
sufficient DHEA for final growth. All Tissues, especially the brain,
compete for DHEA. The hormone, testosterone, increases use of DHEA by
testosterone target tissues, which also includes parts of the brain.
Boys produce more testosterone than females so there is less DHEA, on
average, for left hemisphere growth. In animals studies, it has been
demonstrated that testosterone actually reduces development of the left
hemisphere (Behavioral and Neural Biology 1988; 49: 344). Therefore,
boys, on average, have an increased ratio of right hemisphere to growth
to left. The right side is used more for mathematical and spatial
thinging, therefore, on average, boys out-perform girls in these areas.
If you want to be a good mathematician, you might be tempted to
want more testosterone. In tests of spatial and mathematical reasoning,
males with high testosterone score much worse than those with low
testosterone. High testosterone increases lower brain growth and
development at the expense of even the right hemisphere. That is, in
high testosterone, even the right hemisphere looses in the competition
for DHEA.
I have suggested in past letters to this paper that testosterone
is rising in this society. Most people see it in the 'secular trend,'
that is, boys and girls are getting bigger and reaching puberty earlier.
If testosterone is rising, it not only will affect the size of our
children, but it will also affect their brains. That is, as testosterone
increases it will decrease the ratio of left hemisphere to right. This
will be seen, on aveage, as a decline in reading ability and an increase
in math abilities. In areas where testosterone is very high, reading and
math scores should both decline. The thing that worries me most is that
one of my references points out that 'the left hemisphere also seems to
be the seat of analytical thinking...' According to the National
Assessment of Educational Progress, we may be seeing a real, and in some
areas already significant, decline in functions of the left hemisphere."
James Howard
