If there is one thing which the white man of South Africa is sure about it is the comparative thickness of the “nigger skull,” but this notion also would appear to be one of the many which have no foundation in fact.
The opinion of medical men, based upon actual observation and measurement, is to the effect that there is no evidence to support the contention that the Native skull is thicker than that of the European.[5] That the thick, woolly hair of the Native may account for his supposed comparative invulnerability to head injuries has not occurred to the layman observer who is more often given to vehement assertion than to careful enquiry.
The supposed arrest of the brain of the Bantu at the age of puberty owing to the closing of the sutures of the skull at an earlier age than happens with Europeans is another popular notion for which a sort of pseudo-scientific authority may be quoted from encyclopaedias and old books of travel. The opinion of modern authorities on this subject is that those who say that the closure of the sutures of the skull determines brain growth would or should also say that the cart pulls the horse, for, if the sutures of the Native skull close at a somewhat earlier date in the average Native than in the average European then it simply means that the Native reaches maturity slightly earlier than the average white man.
The loss of mental alertness which is said by some to be peculiar to the Natives at the time of puberty is very often met with in the European youth or girl at that period of life. Competent observers have of late years come to the conclusion that this supposed falling off in intelligence, in so far as it may differ in degree from what has so often been noticed in European boys and girls at that point of development, is due to psychological and not to physiological causes. It is realised that this lapse in mental power of concentration in European youth in the stage of early adolescence is prevented by the force of example and fear of parental and general reprobation coupled with unbroken school-discipline, all of which factors are as yet seldom present in the surroundings of the average Bantu boy or girl.