Re: To whom "Romeo and Juliet" makes no sense?

On Sep 27, 9:39 pm, Tue Sørensen <sorenson...@xxxxxxxxx> wrote:
On 27 Sep., 22:11, Will in New Haven <bill.re...@xxxxxxxxxxxxxxxxxxxx>
wrote:

On Sep 27, 3:58 pm, plausible prose man <Georgefha...@xxxxxxx> wrote:

On Sep 27, 12:46 am, Tue Sørensen <sorenson...@xxxxxxxxx> wrote:
Above-average intelligence is almost certainly not genetic.

 I'm not at all sure why you think that.

The influence of the epigenome, which can be influenced by conditions
during the individual's lifetime, is becoming more and more evident to
researchers.

Indeed it is. This is perhaps *the* most exciting development of the
last ten years;

All that stuff, um...I haven't read the Bell Curve, but I have read
Mismeasure of Man, and Gould doesn't do a good job there, mainly
resorting to the argument from "but what is X?" which I think we all
learned to recognize as concession in late-night half-drunken
arguments.

the discovery that genes tend to be expressed to a
certain degree in certain individuals under certain conditions, and
will be expressed differently under different environmental
conditions. It amounts to a proof that environmental influence matters
enormously.

Which is a very different thing from "there is no genetic component."
There certainly is a genetic component. Tall people have tall kids,
even if they might wind up shorter than they otherwise would be by not
eating right.


Still, there is clearly a genetic influence on intelligence.

"Clearly"? I beg to differ.

Yes, well, that's fine as long as you mostly keep it to yourself.

Well, of course there are genes that code
for the brain and its structures, but there is no universally agreed-
upon definition of *intelligence*.

See?

"but what is X?"

Any IQ test only tests a person's
ability to do that particular test.

I never found this persuasive, and believe me, it wasn't through a
lack of sympathy to the underlying idea.

We don't know what intelligence
is,

Oh, I think we have a pretty good idea, actually. Don't you?

much as we don't know what consciousness is.

There too...

Hence, nobody can
identify genes that code for "intelligence". As a general trait, being
common to all members of the human species, sure, we can define
intelligence as a certain range of mental capacity.

I perfer a certain suite of mental abilities, the relative skill at
each, something like that.

But degrees of
higher and lower intelligence and differences between them in
individuals inside the species, and the causes of such differences?
Perish the thought! There is only speculation and more or less
baseless assumptions about the nature of intelligence. To claim that
intelligence and many other talents (all essentially acquired) are
genetic is to demonstrate just how completely you're disregarding
cultural, social and other environmental influences, and ignoring
education and personal intellectual development.

Sonny, that's just blather.

As long as we do not yet understand the true natural capacities of the
human brain, and have no scientific description of them, by far the
most logical and reasonable

But what are logic and reason?

thing to do is to give the environmental
influence the benefit of the doubt, because it comprises a complex set
of factors that impact on our (intellectual as well as physiological)
behavior across many years, and shape the person we become. Until we
have much more clear info on genes, we must investigate the extent to
which the environmental factors influence our intellectual capacity
and development. That's where explanations can be found. To just
assume that something that complex is genetic is to assume an answer
where there is none (yet) - that's a rigid belief which is not
grounded on scientific evidence. People who believe that intelligence
is genetic are inclined more towards philosophy and religion and
conservatism than towards science and change.

Yeah, like those inscrutable mystics, Vince Sarich and Steven Pinker
and I could go on.

"[edit] Background
Heritability is defined as the proportion of variance in a trait which
is attributable to genotype within a defined population in a specific
environment.[1] Heritability takes a value ranging from 0 to 1; a
heritability of 1 indicates that all variation in the trait in
question is genetic in origin and a heritability of 0 indicates that
none of the variation is genetic. The heritability of many traits can
be considered primarily genetic under similar environmental
backgrounds. For example, Visscher et al. (2006) found that adult
height has a heritability estimated at 0.80, when a similar
environmental background is present, to control for environment the
study only looked at the contribution of heritability to variation
within families. The paper stated that "one can never be sure that the
estimates are correct, because nature and nurture can be confounded
without one knowing it. The authors got around this problem by
comparing the similarity between relatives as a function of the exact
proportion of genes that they have in common, looking only within
families."[2] Other traits have low heritabilities, which indicate a
large relative environmental influence. For example, a twin study on
the heritability of depression in men calculated it as 0.29, while it
was 0.42 for women in the same study.[10]

Heritability for a trait is calculated by measuring how strongly
traits covary in people of a given genetic and environmental
similarity. The most common method is to consider identical twins
reared apart, with any similarities which exists between such twin
pairs attributed to genotype. In terms of correlation statistics, this
means that theoretically the correlation of tests scores between
monozygotic twins would be 1.00 if genetics alone accounted for
variation in IQ scores; likewise, siblings and dizygotic twins share
half of their alleles and the correlation of their scores would be
0.50 if IQ were affected by genes alone. Practically, however, the
upper bound of these correlations are given by the reliability of the
test, which tends to be 0.90 to 0.95 for typical IQ tests[11] Thus,
the actual heritability of IQ will tend to be slightly higher than
attained by estimates derived from studies of monozygotic twins,
though this effect is small.

In the case of the inheritance of IQ or a certain degree of
giftedness, the relatives of probands with a high IQ exhibit a
comparably high IQ with a much higher probability than the general
population. In 1982, Bouchard and McGue reviewed such correlations
reported in 111 original studies in the United States.[12] The mean
correlation of IQ scores between monozygotic twins was 0.86, between
siblings, 0.47, between half-siblings, 0.31, and between cousins,
0.15. From such data the heritability of IQ was estimated at anywhere
between 0.40 and 0.80 in the United States. The reason for this wide
margin appeared to be that the heritability of IQ rises through
childhood and adolescence, peaking at 0.68 and 0.78 in adults, leaving
the overwhelming majority of IQ differences between individuals to be
explained genetically.[13]"

And that ends my
sweeping generalization and rant for today. :-)

Indeed, evidence suggests that intelligence isn't even that
enviromentally based:

"In a series of subsequent articles, Levitt explored other facets of
parenthood and their outcomes. He determined that in spite of the
cottage industry of parenting and the millions of how-to books on the
subject sold every year, who you are matters much more than what you
do. In other words, positive parenting outcomes are linked more
strongly to factors such as socioeconomic status and parental
education than any specific parenting practices. Key to determining
which parenting factors really make a difference to a child's
upbringing, Levitt analyses data from the Chicago School Choice
Program, a longitudinal study of Chicago school students in 60 schools
since 1980, a huge data-set. Factors that are important in determining
high standardized test scores in children include: highly educated
parents, high socioeconomic status, maternal age of greater than
thirty when the child was born, low birth weight, English as the
primary language spoken in the home, parental involvement in the PTA,
and many books in the home environment. Also, adopted children tended
to have lower standardized test scores than their non-adopted peers.
Factors that are not important in determining high standardized test
scores in children include: the family is intact, the parents recently
moved to a better neighborhood, the mother didn't work between birth
and kindergarten, the child attended Head Start (US government program
providing education, health, nutrition, and parent involvement
services to low-income children and their families), the parents
regularly take the child to museums, the child is regularly spanked,
the child frequently watches television, the parents read to the child
nearly every day. Noting the overgeneralization, Levitt explains that
what is important in parenting is who you are, not what you do."

http://www.wikisummaries.org/Freakonomics:_A_Rogue_Economist_Explores_the_Hidden_Side_of_Everything#Chapter_5:_What_Makes_a_Perfect_Parent.3F

ie, exposing a genetically disadvantaged kid to a stimulating
eviroment probably won't turn him into an especially smarter kid, etc.
.

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