ation to intelligence, moreover, has usually been much exaggerated
by anthropologists; for intelligence depends on the rapidity and range
of the acts of associative memory, and this in turn on the complexity
of the neural processes. Brains are, in fact, like timepieces in this
respect, that the small ones work "excellent well" if they are good
material and well put together. Although brains occasionally run above
2,000 grams in weight (that of the Russian novelist Turgenieff weighed
2,012), the brains of many eminent men are not distinguished for their
great size. That of the French statesman Gambetta weighed only 1,160
grams. It must be borne in mind also that there are many individuals
among the lower races and among women having brain weight much in
excess of that of that of the average male white.

Of all the possible ways of treating the brain for the purpose of
testing its intelligence, that of weighing is the least satisfactory,
and has been most indefatigably practiced. A better method, that of
counting the nerve cells, has been lately introduced, but to treat a
single brain in this way is a work of years, and no series of results
exists. In the meantime Miss Thompson, in co-operation with Professor
Angell, has completed a study of the mental traits of men and women
on what is perhaps the best available principle--that of a series
of laboratory tests which eliminate or take into consideration
differences due to the characteristic habits of the two sexes. Her
findings are probably the most important contribution in this field,
and her general conclusion on differences of sex will, I think, hold
also for differences of race:

The point to be emphasized as the outcome of this study
is that, according to our present light, the psychological
differences of sex seem to be largely due, not to difference
of average capacity, nor to difference in type of mental
activity, but to differences in the social influences brought
to bear on the developing individual from early infancy to
adult years. The question of the future development of the
intellectual life of women is one of social necessities and
ideals rather than of the inborn psychological characteristics
of sex.[258]

There is certainly great difference in the mental ability of
individuals, and there are probably less marked differences in the
average ability of different races; but difference in natural ability
is, in the