SIZE OF HEADS

Hokitika Guardian, 6 July 1918, Page 1

SIZE OF HEADS

TEST __ OF BRAIN POWER. Professor R. J. A. Beny, M.D., of Melbourne University, lectured before the Royal Society of New South Wales on “ Brain Growth, Education and Social Inefficiency.” The president of the Society, Mr W. S. Dunn, presided. Prolessor Berry said that there was in every community a large number of people who, though not insane, were mentally inefficient, had defective will control, and might equally well have abnormal instincts. ■ One or other of these factors rendered them incapable of taking their part in the common life of the community. It was now possible to discover these inefficient.-; during school life much more certainly than heretofore Mental dullness, even to idiocy, might occur in either very small or very big heads, as might also genius.

The lecturer directed attention to _ the recent extensive investigation of Mr Porteous and himself on Victorian school children. From the results of this the lecturer was en- ; abled to show for the first time in | the annals of science the amount of i brain which a normal healthy boy I might be reasonably expected to possess .-at every year of life from | birth onwards. In about 20 per cent of the population mental development ceased at or about the level of the 14th year. “ It is most fortunate,” he added, “ that we are now recognising there are mentally defective persons who cannot lie trained to high efficiency in any line: and, secondly, that we have scientific methods for detecting weak mentality even in those individuals who are not recognised as defective by their associates. It is now customary for those who are dealing with the problems of levels of intelligence to classify people in terms of mental age; tliat is to say, to compare them with the average child or youth of various ages. If a half grown boy has only the intelligence of a two-year-old baby, he is technically an idiot. If nn adolescent youth has the intelligence of a bov of from 3 to 7 years, he is called aii imbecile. If be has intelligence of from 8 to 12, or possibly is, he is called a moron. A person who has only the intelligence of a normal boy of 12 years or less is considered feebleminded and incapable of managing himself or his affairs with ordinary prudence, incapable of holding any responsible position where judgment and common sense are requisites.

“ Next in this group come the so-called dull normal people, who cm manage tlieir affairs with a certain degree of prudence, who show some common sense and judgment, but never of a high or even average grade. These various levels of intelligence can now be measured by various psychological methods or tests with rather a high degree of accuracy. It had been already ascertained that of the small-headed boys 50 per cent were either at definite feeble-minded levels or distinctly subnormal, while only 5 per cent were of supernormal intelligence. Of the abnormally large-headed boys, 25 per cent were super-intelligent, whilst only 14 per cent were below average intelligence.”