THE REAL ERROR OF CYRIL BURT 349
roughly scalable along ag dimension.. .g can be viewed as an interspecies
concept with a broad biological base culminating in the primates (p. 251).
Not satisfied with awardingg a real status as guardian of earthly
ranks, Jensen would extend it throughout the universe, arguing
that all conceivable intelligence must be measured by it:
The ubiquity of the concept of intelligence is clearly seen in discussions
of the most culturally different beings one could well imagine—extrater-
restrial life in the universe.... Can one easily imagine "intelligent" beings
for whom there is no g, or whose g is qualitatively rather than quantita-
tively different fromg as we know it (p. 248).Jensen discusses Thurstone's work, but dismisses it as a criti-
cism because Thurstone eventually admitted a second-order g. But
Jensen has not recognized that if g is only a numerically weak, sec-
ond-order effect, then it cannot support a claim that intelligence is
a unitary, dominant entity of mental functioning. I think that Jen-
sen senses his difficulty, because on one chart (p. 220) he calculates
both classical g as a first principal component and then rotates all
the factors (including g) to obtain a set of simple structure axes.
Thus, he records the same thing twice for each test—g as a first
principal component and the same information dispersed among
simple structure axes—giving some tests a total information of
more than 100 percent. Since bigg's appear in the same chart with
large loadings on simple-structure axes, one might be falsely led to
infer thatg remains large even in simple-structure solutions.
Jensen is contemptuous of Thurstone's orthogonal simple
structure, dismissing it as "flatly wrong" (p. 675) and as "scientifi-
cally an egregious error" (p. 258). Since he acknowledges that sim-
ple structure is mathematically equivalent to principal components,
why the uncompromising rejection? It is wrong, Jensen argues,
"not mathematically, but psychologically and scientifically" (p. 675)
because "it artificially hides or submerges the large general factor"
(p. 258) by rotating it away. Jensen has fallen into a vicious circle.
He assumes a priori thatg exists and that simple structure is wrong
because it disperses g. But Thurstone developed the concept of
simple structure largely to claim that g is a mathematical artifact.
Thurstone wished to disperse g and succeeded; it is no disproof of
his position to reiterate that he did so.
Jensen also uses g more specifically to buttress his claim that the
average difference in IQ between whites and blacks records an