Asiaa sivuten:
\doc\web\2000\01\adopiq.txt
Date sent: Mon, 07 Feb 2000 11:03:08 -0500
From: "J. P. Rushton" <rushton@julian.uwo.ca>
Subject: [h-bd] Trans-racial adoptions
Phil Rushton replies to Ken Hirsch who posted: -- What C. Loring Brace
wrote was that the question of whether the differencein intelligence
between blacks and whites is genetic _cannot_ be studied scientifically
until they are perfectly equal in society. That is what Holloway was
objecting to. Do you agree with Brace?
If we are going to rehash the same debate, we should clearly distinguish
between the question of whether the IQ difference is genetic and the
question of how this genetic difference came about. There is much more
evidence about the former question than the latter. Rushton's theories
are quite speculative, but Jensen's theories are concrete and more
readily testable.
REPLY:--
Here is the material on transracial adoptions from the Abridged edition
of my book Race, Evolution, and Behavior, which has now been depublished
by Transaction as a result of the brouhaha.
(
http://www.nationalpost.com/home.asp?f=000131/191150; also see
Chronicles of Higher Education, January 13, 2000)
Anyone wanting a copy for a collectors item please send me your snail
mail address privately.
Trans-racial Adoption Studies
The best evidence for the genetic basis of race-IQ differences comes
from trans-racial adoption studies of Oriental children, Black children,
and Mixed-Race children. All these children have been adopted by White
parents at an early age and have grown up in middle-class White homes.
One well known trans-racial adoption study is Sandra Scarr's Minnesota
project. The adopting parents were all White and lived in good
middle-class homes. The adopted children were either White, Black, or
Mixed-Race (Black-White) babies. The children took IQ tests when they
were seven years old and again when they were 17.
In their initial report, the authors thought that their study proved
that a good home could raise the IQs of Black children. At age 7, their
IQ was 97, well above the Black average of 85 and almost equal to the
White average of 100. However, when the children were retested at age
17, the results told another story (reported in the 1992 issue of
Intelligence).
At age seven, Black, Mixed-Race, and White adopted children all had
higher IQ scores than average for their group. Growing up in a good home
helped all the children. Even so, the racial pattern was exactly as
predicted by genetic theory, not by culture theory. Black children
reared in these good homes had an average IQ of 97, but the Mixed-Race
children averaged an IQ of 109, and the White children an IQ of 112.
The evidence for genetic theory got stronger as the children grew
older. By age 17, the IQs of the adopted children moved closer to the
expected average for their race. At age 17 adopted White children had an
IQ of about 106, Mixed-Race adoptees an IQ of about 99, and adopted
Blacks had an IQ of about 89. IQ scores are not the only evidence in
this study. School grades, class ranks, and aptitude tests show the same
pattern.
When Sandra Scarr got the results of her follow-up study at age 17, she
changed her mind about the cause of why the Blacks and Whites differed.
She wrote, "those adoptees with two African American birth parents had
IQs that were not notably higher than the IQ scores of Black youngsters
reared in Black families." Growing up in a White middle-class home
produced little or no lasting increase in the IQs of Black children.
Some psychologists disagreed with her. They claimed "expectancy
effects," not genes, explained the pattern. They argued that the Black
and White children were not treated the same. Even if parents took good
care of their children, the schools, classmates, and society as a whole
discriminated against Black children and this hurt their IQs. Because
we expected Black children to do poorly in school, they lived up to our
low expectations.
Is there any way to decide between the genetic theory and the
expectancy theory? There is. A special analysis of the Scarr study
compared parents who believed that they had adopted a Black baby but,
really, had adopted a Mixed-Race (Black-White) child. The average IQ for
these Mixed-Race children was just about the same as for other
Mixed-Race children and above that for adopted Black children. This was
true even though the parents who adopted these Mixed-Race children
thought their babies really had two Black parents.
Chart 9 summarizes the results for Oriental children adopted into White
middle-class homes. Korean and Vietnamese babies from poor backgrounds,
many of whom were malnourished, were adopted by White American and
Belgian families. When they grew up, they excelled in school. The IQs of
the adopted Oriental children were 10 or more points higher than the
national average for the country they grew up in. Trans-racial adoption
does not increase or decrease IQ. The three-way pattern of race
differences in IQ remains.
(Insert Chart 9 on Following or Facing Page)
The Minnesota Transracial Adoption Study also showed that there are
race differences in personality. Black 17-year-olds were more active and
more disruptive than White 17-year-olds. Korean children raised in White
American families were quieter and less active than White children. The
results again show the three-way racial pattern.
