Under the engaging title of The Seven Ages of the Mind," a correspondent contributes to "The Times" Educational supplement an_interesting article on the subject of mental development, discussing the view that the development of intelligence stops at a definite age, at which it remains permanently fixed. The writer points out that determination of this age has naturally been a matter of much difficulty but after a good deal of fluttering in the period between 14 and 16 a point has been selected somewhere between 15 and 16, and 16 is being gradually adopted' as the conventional chronological age to be used as the denominator in the fraction that expresses the "quotient of intelligence" for adults, whatever their chronological age happens to be. "Uneasy questionings" ho ever, are said to have arisen with regard to the final stoppage of development long before that age, Levets oF INTELLIGENCE.
The writer quotes some interesting statistics of psychological tests applied to the American army. The tests were applied in 1,700,000 cases, and the "general " conclusions" reached make rather startling reading. Some of them are set forth in the lectures of Mr. H. H, Goddard at Princeton University, published a book under the title "Human Efficiency and Levels of Intelligence." The principal theory advanced is that every hwuan being reaches at some time a level of jntelligence beyond which he never rises, and that these levels range all the way from idiocy at one end to genius at the other. Mr. God. dard does not subscribe to the 16- year-old limit, his highest forms of intelligence being placed in a 19- year-old grade: even so, he finds the adults of a nation falling naturally into certain strata of intelligence, and applies the theory to his own countrymen with rather devastating results.
ApuLts wits a CHILD's Taking the population of the Unit ed States as being 100,000,000, he places 4,500,000 in stratum "A" as possessing "very superior" intelligence, and 9,000,000 in stratum "B" as "superior," the two classes having a "mental age" ranging frou 17 to.19. As to the lower strata, the Professor finds that 70 per cent. of the population of America, the "C's" and all below them—have a mental age of less than 14. Still more striking is the statement that 45 out of every hundred Americans have a mental age of 12 or under. Little wonder (says the writer) that Mr. Goddard and his friends are
Text read from the printed page and cleaned; old type leaves the occasional error.