THE REAL ERROR OF CYRIL BURT 335
In educational practice the rash assumption that the general factor has
at length been demolished has done much to sanction the impracticable
idea that, in classifying children according to their varying capabilities, we
need no longer consider their degree of general ability, and have only to
allot them to schools of different types according to their special aptitudes;
in short, that the examination at 11 plus can best be run on the principle
of the caucus-race in Wonderland, where everybody wins and each get
some kind of prize (1955, p. 165).
Thurstone, for his part, lobbied hard, producing arguments
(and alternate tests) to support his belief that children should not
be judged by a single number. He wished, instead, to assess each
person as an individual with strengths and weaknesses according
to his scores on an array of PMA's (as evidence of his success in
altering the practice of testing in the United States, see Guilford,
1959, and Tuddenham, 1962, p. 515).
Instead of attempting to describe each individual's mental endowment
by a single index such as a mental age or an intelligence quotient, it is
preferable to describe him in terms of a profile of all the primary factors
which are known to be significant. ... If anyone insists on having a single
index such as an I.Q., it can be obtained by taking an average of all the
known abilities. But such an index tends so to blur the description of each
man that his mental assets and limitations are buried in the single index
(1946, p. 110).
Two pages later, Thurstone explicitly links his abstract theory of
intelligence with preferred social views.
This work is consistent not only with the scientific object of identifying
the distinguishable mental functions but it seems to be consistent also with
the desire to differentiate our treatment of people by recognizing every
person in terms of the mental and physical assets which make him unique
as an individual (1946, p. 112).
Thurstone produced his fundamental reconstruction without
attacking either of the deeper assumpdons that had motivated
Spearman and Burt—reification and hereditarianism. He worked
within established traditions of argument in factor analysis, and
reconstructed results and their meaning without altering the prem-
ises.
Thurstone never doubted that his PMA's were entities with
identifiable causes (see his early work of 1924, pp. 146-147, for the