Educability-and-Group-Differences-1973-by-Arthur-Robert-Jensen

132 Educability and Group Differences
they are the ethnic labels people use to describe themselves and
the more obvious physical characteristics such as skin color, hair
form, facial features, etc., by which persons roughly judge one
another’s ‘race’. Ordinary social criteria make for unreliability
in the classification of ‘borderline’ or ambiguous cases. Nevertheless,
for the major racial groups there is undoubtedly a high degree
of correspondence between social and biological criteria. If one
were to sort school children, for example, into three racial groups -
Negro, Oriental, and Caucasian - by the ordinary social criteria,
one would find a very high concordance of classification if one
used strict biological criteria based on the frequencies of blood
groups, anthropometric measures, and other genetic polymorphisms.
What the latter measures would reveal are degrees of racial
admixture, and a consequent continuity of genetic differences from
one group to another, with only modal genetic differences between
the groups. Studies of behavioral differences in relation to ethnic
classification would be much improved by using biological in
addition to social criteria of racial membership, so that correlations
between continuous variables could be obtained as well as mean
(or median) differences between groups. But most studies of race
differences in mental characteristics have compared groups selected
solely by social criteria. If the observed behavioral differences are
due only to social factors, then the social definition of race should
be quite adequate, and, in fact, it should be the most appropriate
definition. But if the groups are, in fact, genetically overlapping
because each one’s gene pool contains some admixture of the other,
use of the social criterion alone can only result in a blurring and
underestimation of the racial genetic aspect of the measured
behavioral difference. Because of varying degrees of racial admixture
in different groups and localities, one should expect to find variable
differences between socially defined racial groups. A common error
is to think of socially defined racial groups as genetically homogeneous.
They surely are not.
Another block to clear thinking is to regard a race as a kind of
Platonic ideal, without reference to any actual population group.
Observable samples of subpopulations, however they are defined,
cannot be regarded as representative of some Platonic racial group.
Such Platonic racial groups do not, in fact, exist, except in some
people’s imaginations. Samples of a subpopulation (racial, socioeconomic,
or whatever) are merely representative (if properly