Volumen cerebral, substancia gris y raza. ¿un hecho o una ficción?

Abstract

A critical review is given of those factors which mav be accompanied by variations in brain weight, viz. sex, body sizq age of death, nuhitional state in early life, source of the sample, occupational group, cause of death, lapse of time after death, temperature after death, anatomical level of severance,
Presence or absence of cerebrospinal fluid, of meninges and
of blood-vessels. Valid comparisons between the brain-weight
of human populations should take all, or several, of these
variables into account; however, published studies have not
done so, despite claims to the contrarv. The ideal sample is
from subjects who have died suddenly- without prior disease:
while three such samples are on record for Europeans, none
has been recorded for Negroes. The brain-weight of healthy
Negroes is not known. Most published interracial comparisons
are invalid. The histological, chemical and functional counterparts of big and small brains in modern man are not known. Published interracial comparisons of thickness of the cerebral cortex and, particulariy, of its supragranular layer, are technically invalid: there is no acceptable proof that the cortex of Negroes is thinner in whole or in any layer, than that of Europeans. It is concluded that vast claims have been based on
iusubstantial evidence.