Re: Flynn Effect ...yes testosterone (James Howard)

James Howard (
Fri, 08 Nov 1996 13:46:43 GMT

Re: Flynn Effect ...yes, testosterone

James Howard responds:

Thank you for your reponse, Bryant. Since posts and responses sometimes
can become confusing, I took your post and placed "Bryant said" before your
remarks and "James Howard said" before mine. Where I answer you below,
I use "James Howard responds."

James Howard said:
>Well, I guess I misinterpreted "worldwide," from my source. However, I
>suggest the remainder of your information is in total agreement with my
>hypothesis. You see, I predict that increases in testosterone are adversely
>affecting development of the "verbal" side of the brain. The Flynn Effect is
>mainly an increase in nonverbal IQ.

Bryant said:
There does seem to be an association between androgens and verbal IQ.

James Howard responds:
Again, the Flynn Effect is known to represent an increase in nonverbal IQ. It
is my hypothesis that the Flynn Effect results from increases in testosterone.
The mechanism I propose is that testosterone adversely affects
development of the left hemisphere, while stimulating development of the
right hemisphere. The left hemisphere is the "verbal" hemisphere, while the
right hemisphere is the "nonverbal" counterpart. As this accrues over time,
verbal IQ declines, while nonverbal IQ increases. (I explained this in more
detail in "math and English," June 18, 1996, sci.anthropology.) For sake of
support of this idea, a "backward" situation has been reported in the
literature. That is, if testosterone (androgen) reduces development of the
left hemisphere, then "congenital androgen deficiency," lack of androgen,
should increase left hemisphere abilities and, therefore, verbal abilities.

Cappa, SF et al., "Patterns of Lateralization and Performance Levels for
Verbal and Spatial Tasks in Congenital Androgen Deficiency" Behav Brain
Res 1988; 31: 177

"The effects of congenital deficiency of gonadal hormones on verbal and
spatial performance and on the establishment of hemispheric asymmetries
were investigated in a group of patients with idiopathic hypogonadotropic
hypogonadism. The patients showed a left hemispheric advantage for verbal
material and were mildly impaired, mainly on tasks involving a short-term
memory load, in comparison with a matched control group. These results do
not indicate a specific role of gonadal hormones on the establishment of
hemispheric asymmetries. Lack of exposure during brain development
results in a decrease in memory functions which is not specific for verbal or
spatial material."

James Howard said:
>Therefore, according to my interpretation of this real, small increase (see
just below), the Flynn Effect should affect Blacks more than Whites. Blacks
produce more testosterone (see some of my other posts for the citation).

(James Howard interjects here: In your response to me, here, of November
5th., you support my prediction that Blacks should be more affected than
Whites. Bryant said: "Blacks' are incresing [in IQ scores] more quickly than
whites, and the lower tail of the score distribution is increasing more rapidly
than the upper scores." )

Bryant said:
Blacks also occupy the lower SES disproportionately, and low SES whites
are enjoying Flynn Effect benefits as well. In Denmark, I believe, a
study on Flynn Effect IQ gains showed that almost all of the change was
in the lower IQ folks' improvements. That's why some of us working on
this topic believe that environmental insults account for IQ differences
between races or populations. There may be another correlation between
these factors and testosterone, I suppose, but we shouldn't reject the
role of improved developmental environments just yet.

James Howard responds:
I can tell from these remarks that you responded to individual statements of
my post, before you read my entire post. For example, I cited the Danish
study as support of my hypothesis a little later in my post, yet you make
these statements (just above) and thank me for the citation later in your
remarks (see below). More importantly, I explain, again a little later, that I
think "improved developmental environments" may actually make conditions
worse and I explained why. Of course, the Flynn Effect should also affect
Whites. My work suggests that testosterone is increasing in all races; Blacks
produce more testosterone than Whites, so the effects, by being worse in
Blacks, support my hypothesis. (I am not out to disparage Blacks.) I will
add that I think testosterone may increase to very high levels, whereby it will
cease to produce a secular trend and cause a negative impact. This is how
testosterone affects human evolution. This is what happened to A. robustus
and similar hominids. Currently, there are areas in the world where the
secular trend is not occurring; some say it is reversing.

Tobias PV "Adult Stature in Sourthern African Negroes--Futher Evidence on
the Absence of a Positive Secular Trend," S Afr Med J 1990; 78: 97

The continuing search for data bearing on secular changes of adult stature in
disadvantaged or Third-World communities led to the analysis of two sets of
data. One was unpublished but was kindly made available by Professor H.C.
Seftel, and was based on a study of 5,018 adult and sub-adult male black
subjects living in Johannesburg. The other dealt with black miners and the
relevant data on adult and sub-adult stature had been published by Dr
J.G.D. Laing. Both sets of results were analysed by the method of age-
ranking of the cross-sectional data and correcting them, where applicable,
for 'personal shrinkage' after 30 years of age. The former results proved
suitable for the analysis and the reduced data showed clear evidence that
the Johannesburg population concerned had not been subject to a secular
trend towards increased adult mean stature over the period c. 1919 - c.
1950. This is a further example, over and above those already adduced from
studies in Asia, Africa, Meso- and South America, that many of the world's
agrarian and pastoral communities have shown an absent or even a
negative secular trend, during some of the time that First-World populations
have shown a positive secular trend. The data for black miners proved to be
too heterogeneous for this approach to be applied validly to them.

James Howard said:
>You mention that this effect is occurring most rapidly in the "lower end of
the IQ score distribution." I know this is true, and it may be a bad sign, not
>good one. You imply that "improvements..." are the source of the Flynn
>Effect in Blacks. That may be true, but it may just make things worse. (I
do not want to be misinterpreted here. I think the very best civilizations
should do these things for the most vulnerable, and I am thankful I live in
one.) However, these improvements will increase the numbers of people
who are higher in testosterone.

Bryant said:
One of the problems with Eugenics is that what constitute "good genes" in
the present environment can very quickly become "bad genes"... if the
good of humanity is the concern you're addressing, maintaining as much
genetic variability as possible should be your goal.

James Howard responds:
I never mentioned Eugenics, why are you? My work is about the ratio of
people of high testosterone to the ratio of people of lower testosterone in a
population. People of higher testosterone produce more children than those
who are of lower testosterone. The percentages can change within a
relatively few generations.

James Howard said:
>That is, these improvements increase the "feed and breed" phenomenon.
If you will reread my "Current signals of testosterone," you will read that
young Black teenagers are rapidly reproducing, compared to their older
counterparts, who already are reproducing faster than Whites.

Bryant said:
If testosterone production is so heritable as you suggest here, how is it
that you assert dramatic increases in androgen levels between generations?
Am I misunderstanding you?

James Howard responds:
Again, people of higher testosterone will reproduce faster than those of lower
testosterone. The percentage changes with each generation.

James Howard said:
>It is also known that violence, among Blacks, is greatest among the very

Bryant said:
Violence among disenfranchised young *males* is very high. There are a
number of socioecological factors in ghetto neighborhoods which can
account for the high representation of black men in violent and property

James Howard responds:
What you just said is the "status quo." I disagree. The grandparents of
"disenfranchised young males," had socioeconomic condidtions at least as
bad, perhaps worse, as the kids today. The difference is that the
testosterone levels are higher. My work suggests increased testosterone
increases impulsive behavior. The violence is the result of lack of control of
impulses, in response to problems, perceived and real, that were also faced
by these people during the Depression. Many Black women, who live in
ghettos, face tremendous problems, yet it is men who commit acts that
result in incarceration. Men produce more testosterone than women.

James Howard said:
>This has already been found in a Danish study of 1987. "We present data
>showing a substantial increase in both the intelligence test scores and
>educational levels of 71,678 Danish males born between 1939 and 1958.
>However, a decline in the test scores within the highest educational levels
>accompanies the increase in proportions attaining those levels." Nature
>1987; 325: 119

Bryant said:
Thanks for the citation.
The upper limit to IQ suggests that there is, after all, a species-typical
developmental "target" for intelligence which is compromised by
developmental stressors (hence, the increases we discussed above are
happening at the lower tail of the score distribution).

James Howard responds:
Bryant, please read more carefully. In the quotation, just above, it is clearly
stated that "a decline in the test scores within the highest educational levels
accompanies the increase in proportions attaining those levels." The people
in this upper group are losing IQ points, on average. This is the group most
unaffected by "stressors." Your statement, just above, is not supported.

James Howard said:
>I interpret this to mean that Danish males are increasing in
>testosterone levels, and that it is beginning to affect their brightest. That
>is, I think testosterone is beginning to adversely affect the entire brains of
>this population. (Hopefully, this will allay some of the "enlightened" or

Bryant said:
Is there data on Danish hormone levels changing?

James Howard responds:
I could not find any studies. I certainly wish I could.

James Howard said:
>15 points were gained in two generations. Fifteen points over 20 to thirty
>years is less than one point increase per year. This is small!

Bryant said:
If 15 points is small, then we need not concern ourselves with mean IQ
differences between racial groups. I think I disagree. While I don't
believe that IQ is a unidimensional measure of "merit" or "ability" (as
some IQ researchers apparently do), I do believe that the components of
intelligence captured by IQ tests constitute potentially important parts
of social success.

James Howard responds:
Bryant, I did not say 15 IQ points is small. Again, I did not say 15 IQ points
is small! "Less than one point increase per year" is small. Again, I say less
than one point increase in IQ per year is small. Your statement, just above,
is not based on anything I have posted. I am using the "current signals of
testosterone" to demonstrate that my theory of human evolution is currently
occurring in a very visible manner. I intend this to support my overall theory
of human evolution. What is very important here is that the large increases
in brain size in hominids will not be repeated (see below). However, the
increase in testosterone in "feed and breed" situations will always occur. I
contend it causes the "secular trend" and the Flynn Effect. (Bryant, if you
want to discuss the standard deviation difference in IQ between Whites and
Blacks, you start a thread.)

Bryant said:
I'm not rejecting your ideas outright, by the way; 'just presenting some
viable alternative explanations. While I agree that brain size and IQ
correlate, I disagree with your contention that this correlation is
causal. I think that it's a loose correlation caused by a common
underlying developmental factor (that is, a factor behind both IQ and
brain size).

James Howard responds:
I have suggested that the Flynn Effect is the result of increases in
tesosterone. I have suggested that the small increases in brain size in early
hominids is due to increases in testosterone. Therefore, I say the small
increases in brain size in the early hominids is due to the Flynn Effect. My
theory suggests the large increases in brain size of the later hominids is due
to effects of the hormones, melatonin and DHEA.

Bryant said:
I do believe that Eugenics thinking is tricky--we have learned repeatedly
(speaking for myself, just in the past year!) that a perfectly obvious
and intuitive correlation can fall away when confronted with new data.
Besides which, what is adaptive is necessarily context specific, and not

James Howard responds:
My work is not about eugenics in any manner or form. Eugenics is the study
of human improvement by genetic means. My work is the study of how
genes are transcribed and replicated. My theory of human evolution is a by-
product of my explanation of how genes are controlled.