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

Subpopulation Differences in Educability 29
fc-rr.. Unlike such terms as social class and race, a subpopulation
ires not connote more than its bare operational definition. Thus,
ibe term subpopulation does not beg any questions. It can help to
prevent us from mixing up the questions with the answers. And
k can help to forestall fallacious thinking about social classes and
noes as Platonic categories. A subpopulation is simply any particular
subdivision of the population which an investigator chooses to
select for whatever purpose he may have. The only requirement
3 rperational definition, that is to say, clearly specified objective
rr-.teria for the inclusion (and exclusion) of individuals. The
reliability of the classification procedure is strictly an empirical
: -rstion and not a matter for semantic debate. It can be answered
terms of a reliability coefficient, which can take any value from
0 (no reliability whatsoever) to 1 (perfect reliability). A subpopula-
:::>n can consist of redheads, or females, or owners of a Rolls
Royce, or persons with incomes under $4000 per annum, or
whatever criterion or combination of multiple criteria one may
choose. All other questions follow, their relevance depending on
the purposes of the investigator.
The subpopulations we shall be most concerned with in the
following discussion are Negroes and whites as they are ordinarily
identified in our society. Studies of Negroes have at least the
common criterion for inclusion in this subpopulation that they
ire those individuals (or their parents) who identify themselves
is Negroes and are so identified by others. The degree to which
this criterion has biological correlates is an empirical question.
It undoubtedly does have a number of known biological correlates
- skin color, hair texture, certain physical features, and distributions
of blood groups, which distinguish the Negro from other sub-
Dopulations. Obviously, the introduction of other criteria would
oermit the further subdivision of this large subpopulation. The
subpopulation of whites includes those who call themselves ‘white’,
or Caucasian, and are usually of European ancestry; it usually does
not include other subpopulations such as Orientals, Mexican-
Americans, and American Indians.
IMPORTANCE OF THE QUESTION
Is the question of the causes of subpopulation differences in
educational and occupational performance of any importance to