[Paleopsych] ScienceWeek Editorials
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ScienceWeek Editorials
http://scienceweek.com/editorials.htm (content changes)
[11]Brain Size and the National Review - October 30, 2005
[12]Creationism vs. Sanity - January 23, 2005
[13]Harvard, Women, and Science - January 19, 2005
October 30, 2005
Brain Size and the National Review
When politics makes an incursion into science, a common result is
distortion and a misinformed and ill-served public. Of course, some
people don't care much about the public. In the November 7, 2005 issue
of the National Review magazine, a frequent repository of right-wing
slop and spittle, an article touts two papers that recently appeared
in a scientific journal (Science September 9, 2005 309:1717,1720). The
major point of the National Review article is that the two scientific
papers present evidence that different human groups may have different
gene frequencies influencing brain development, one consequence of
which is that "our cherished national dream of a well-mixed and
harmonious meritocracy with all groups equally represented in all
niches, at all levels, may be unattainable." The title of the National
Review article is "The Spectre of Difference". The interest of a
self-proclaimed arch-conservative magazine like the National Review in
this idea needs no explication.
The two scientific papers concern two genes, one called
"microcephalin", and the other gene called ASPM (abnormal spindle-like
microcephaly associated). Both genes may contribute to the regulation
of brain size, since mutations of either gene cause pathological
microcephaly. Both papers are from the research group of Bruce T.
Lahn, a human geneticist at the University of Chicago. The first paper
purports to present evidence that a genetic variant of microcephalin
in modern humans that arose 37,000 years ago increased in frequency
too rapidly to be compatible with neutral genetic drift, and thus must
have spread under strong positive natural selection, which in turn
suggests the ongoing evolutionary plasticity of the human brain. The
second paper, concerns the gene ASPM , and here also the authors
interpret their analysis as suggesting that the human brain is still
undergoing rapid adaptive evolution.
All of which is politically neutral, except that the authors also
present arguments that the frequencies of these two genes are
undergoing adaptive evolution that varies with different geographical
populations. In plain words, the data are presented as suggesting that
the brain size of different ethnic groups and races (and dependent
cultural outputs of such brains) are evolving (and have evolved) at
measurably different rates.
Unequivocal in the two scientific papers is the idea that brain size
is related to culture
Such is the gist of what the National Review picks up for its readers,
the article proposing that "results like these out of the human
sciences should prompt us to begin some hard thinking about our
society, and about what we can reasonably expect social policies to
accomplish."
But maybe before we get to hard thinking about social policies we need
some hard thinking about evidence and conclusions.
Let's consider the two scientific papers.
In the first paper, the demonstration of evolutionary selection is
inferential and not definitive. The authors state, "Our data on
haplotype 49 are consistent with these signatures of selection."
Yes, consistent only: no anthropological conclusions are justified,
and the so-called "signatures" of selection are provisional.
In the first paper, the anthropological statements are essentially
speculations, to wit: "Such population differentiation may reflect a
Eurasian origin of haplogroup D, local adaptation, and/or demographic
factors such as a bottleneck associated with human migration 50,000 to
100,000 years ago."
Again, speculation: "may reflect". In translation: "We think this work
may be related to demographic anthropology, but we don't know."
In the second paper, concerning the proposed adaptive evolution of the
gene ASPM, the authors conclude: "Although the age of haplogroup D and
its geographic distribution across Eurasia roughly coincide with two
important events in the cultural evolution of Eurasia -- namely, the
emergence and spread of domestication from the Middle East ~10,000
years ago and the rapid increase in population associated with the
development of cities and written language 5000 to 6000 years ago
around the Middle East -- the significance of this correlation is not
yet clear."
Exactly so. The coincidence is rough, the significance unclear, and
the authors nowhere discuss the important fact that within and across
present human populations, studies of brains without pathology show no
evidence of correlation of brain size with brain function or cultural
"achievement". Certainly, if the authors are working on genes
apparently associated with brain size, and the authors are also
interested in relating their work to current anthropology, one would
expect some discussion of their problem, to wit: If greater human
brain size is still undergoing evolutionary selection, how come we
have no strong correlations between brain size and important
functional attributes of the human nervous system? If the brain is
still evolving in size, what are the conceivable selection pressures,
given no apparent correlation between non-pathological brain size and
function? We're unhappy that the authors were not urged by the
referees to make some statements about these questions.
We're also fascinated by the opening sentence of the first paper: "The
most distinct trait of Homo sapiens is the exceptional size and
complexity of the brain (1,2). That's good, but the problem is the two
references are 46 years old and 32 years old, respectively, and we're
trying to imagine why anyone would choose these particular references
for a report of such research. If we're to choose old references, why
not choose von Bonin? But maybe that would be against the approach of
these authors. Consider, for example, the following quotation from von
Bonin:
"The results of our inquiries into the brains of fossil men are
somewhat meager: we cannot deduce any details about their mental life,
whether they believed in God, whether they could speak or not, or how
they felt about the world around them... That the brain increases in
size as we go from the Australopithecinae to modern man -- or to the
Upper Paleolithics, for that matter --is quite obvious and, of course,
gratifying. But the meaning of the increase is again not quite clear
because, as we all know, brain size as such is a very poor indicator
of mental ability. This has been shown best perhaps by Pearson (1925)
some years ago. In his series, very gifted persons, such as Leon
Gambetta, Anatole France, or Franz Joseph Gall, had very small brains,
of about 1100 grams. Other equally gifted persons had very large
brains; thus Byron and Dr. Johnson had brains of about 2000 grams.
And, of course, some very ordinary persons had equally large brains.
So brain size was certainly not very important, and the correlation
between brain size and mental capacity was insignificant. But whether
this argument can be extended to an evolutionary series is again
another matter. For one thing, we know far too little about the bodily
proportions of fossil forms. Obviously, the brain stands in a certain
relation to the rest of the body, and this rest is still largely
hidden from us. Brain size as such is none too meaningful. Moreover,
mere size completely leaves out of account the inner structure of the
brain, which may be different in different forms and which may
determine to a great extent what the brain can do." Gerhardt von
Bonin: THE EVOLUTION OF THE HUMAN BRAIN University of Chicago Press,
1963, p.76
So why cite Spuhler (1959) and Jerison (1973) rather than von Bonin
(1963)?
Our final comment is that human brain size, as a phenotype, has
important determinants arising from epigenetics, fetal environment,
and postnatal environment, in addition to the probable involvement of
many gene networks, and at the present level of our ignorance, any
attempt to lock in brain size to the activity of a few genes is most
likely an exaggeration. We would especially emphasize that whatever
genes or gene complexes may have been involved with the marked
increase in brain size apparently associated with our split from the
great ape line, the same genes or gene complexes may not at all be
involved with any apparent changes in brain size during the Holocene.
There is certainly no reason to believe that the human brain has
stopped evolving, and certainly brain size is a biological parameter
that may indeed be changing, but we don't think this work is of much
particular anthropological significance. We would say the work needs
to be done (and supported), but we are not at the point yet of making
important conclusions from such studies.
And finally there is this: Is it total brain size that's important or
the surface area and depth of neocortex? With an increase in total
brain size may come an increase in subcortical structures and not
necessarily a concomitant increase in neocortex at all, given the
existing foldings of neocortex. In plain words: Could evolution be
dumbing down the brain? (What an idea!)
In general, if there are any anthropologists and psychologists
listening, we would urge them not to jump to any conclusions on the
basis of this work alone or on the basis of any work like it. We
certainly need to identify the critical neurobiological variables that
may be associated with individual psychological performance and with
cultural change, but our view is that we're not there yet, not even
close.
As for the National Review, we suggest they do more homework. The
author of the article (John Derbyshire) calls himself "a simple
Darwinian rightist".
Indeed.
The Editors
ScienceWeek
_________________________________________________________________
January 23, 2005
Creationism vs. Sanity
One grows tired of the recurring efforts of inadequately educated
religionists to base the teaching of science in schools on biblical
passages written during a time when civilization and understanding of
the natural world were both primitive.
In a country of nearly 300 million people, there will always be some
people who, because of "religious" conviction, believe the Earth is as
flat as a pancake, a few thousand years old, and resting on the backs
of four giant elephants. Their belief is unfortunate. What is even
more unfortunate is teaching our children that such beliefs, because
they are "religious", deserve respect.
Creationism and its latest effluvium, intelligent design, are not
science, not evidentiary, not even close to science, and do not
deserve respect as material to be taught to children in public
schools. The idea of imposing one's religious views on others via
public education is totally un-American, and the people who promulgate
that idea need to be called that -- un-American.
Religionists who accept the work of their God as revealed by science,
and who understand that creationism is blasphemy, need to come out
into the arena and be heard.
Scientists who devote their lives to science and scientific attitudes
and scientific truths also need to come out into the arena and be
heard with their strongest voices.
Science teachers who find these creationist crusades obnoxious and
potentially damaging to the children they teach also need to come out
into the arena in droves and wage the battle of their intellectual
lives.
It is time. We are nearly 150 years after Darwin's Origin of Species,
and it is time for the United States, the foremost scientific
enterprise on the planet, to deal firmly with this issue. People are
free in the US to practice any particular religion. They are not free
to impose that religion on others, and they are certainly not free to
force the teaching of their religious beliefs in the public schools.
We call for an end to stickers on textbooks telling children that
evolution is only a "theory". We call for an end to mandated teaching
of creationism or intelligent design or any other attempt to subvert
the public school teaching of science as it is currently understood by
the scientific community. We call for all scientists, educators, and
thinking Americans to raise their voices in a decisive confrontation
against insidious and un-American anti-scientific dogma.
The US Supreme Court owes the American people a unanimous and
unambiguous rejection of religionist attacks on science education.
The Editors
ScienceWeek
_________________________________________________________________
January 19, 2005
Harvard, Women, and Science
The recent comments by Lawrence H. Summers, the president of Harvard
University, suggesting that biological differences between the sexes
may be one explanation why fewer women succeed in mathematics and
science careers, is evidence of at best a sophomoric understanding of
the professions of science and mathematics, and at worst possible
evidence of brain damage. Dr. Summers is an economist, not a scientist
and not a mathematician. At the present time, approximately half the
graduating PhDs in chemistry and MDs in medicine are women, and more
than a third in the biological sciences, particularly in molecular
biology. One can assume that any of these new women graduates knows
more science and mathematics than Dr. Summers, and in addition one
suspects that any of these new women graduates knows more about the
problems of women in science and mathematics than Dr. Summers does.
If Dr. Summers is really interested in understanding the present
situation of women in science and mathematics, he ought to have a
serious look at the history of his own university. In general, Harvard
University has never been known as a leader in the intellectual
emancipation of women, and throughout most of its existence, Harvard
was an all-male college that frowned on the idea of women in
intellectual pursuits. In the early years of stellar spectroscopy at
the Harvard Astronomical Observatory, for example, nearly all the data
were catalogued and analyzed by female astronomers, called
"computers", who were trained professional astronomers but forbidden
because of their sex to use the telescopes. Women astronomers at
Harvard were not allowed routine access to the telescopes until the
1950s. It is an irony of the social history of science that the work
of such female astronomers as Henrietta Swan Leavitt (1868-1928) and
Annie Jump Cannon (1863-1941) came to be of greater significance than
the work of many of the male astronomers who considered these female
astronomers to be no more than menial assistants.
If understanding of women in science is the objective, after an
examination of the history of women at Harvard, we suggest to Dr.
Summers that he start thinking about attitudes rather than biological
differences, attitudes of men in science toward women in science, and
attitudes of university presidents who are supposed to lead forward
rather than backward.
In truth, this problem of attitudes toward women of accomplishment is
so old it feels trite. Plato, after all, that old Greek so clever with
his words, already pointed out in his time that wasting women, wasting
the intellectual capabilities of half the population, was a stupid
strategy for any society.
As always, in science or anywhere else, "old-boy" attitudes are the
attitudes of old boys.
The Editors
References
11. http://scienceweek.com/editorials.htm#051030
12. http://scienceweek.com/editorials.htm#050123
13. http://scienceweek.com/editorials.htm#050119
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