MEASURING HUMAN INTELLIGENCE 



'Why should we not ascertain the grade of intelligence necessary in every 



essential occupation and then entrust that work only to those people who 



have the necessary intelligence?" Dr. H. H. Goddard thinks this 



would not be difficult to do. His convincing book 



is here reviewed. 



Paul Popenoe 



WHEN psychologists announced, intricacies 

 after examining 1,700,000 men, 

 that the average mental age of 

 men in the army was about 13 years, 

 they attracted widespread attention 

 to the doctrine of mental levels. 

 But, says Dr. Goddard, let us not 

 commit the fallacy of the average. 

 "The average only means that there 

 are about as many of lower intelli- 

 gence as of higher. 



"We have seen that while the 

 average is perhaps thirteen to fourteen 

 years and there are 25,000,000 people 

 of this intelligence and 45,000,000 still 

 lower, there are also 30,000,000 above 

 the average and 4,500,000 of very supe- 

 rior intelligence ^ 



Dr. Goddard discusses at some 

 length the way in which these levels 

 of intelligence are measured, and the 

 validity of the methods used. 



"The theory of mental levels holds," 

 he says, "that every human being 

 comes into the world with a potenti- 

 ality for mental development that 

 will carry him just to far, and that 

 barring those accidents that may stop 

 a person from reaching the develop- 

 ment that would have been normal 

 to him, nothing can, to any great 

 extent, affect the mental level to which 

 he will finally attain. 



"Why is this view hard to accept?" 



KNOWLEDGE VS INTELLIGENCE 



"Probably the first and most im- 

 portant reason is that we have generally 

 confused intelligence with knowledge. 

 Having no way to evaluate either 

 one we have been lost in the 



and confusion results. . . 

 The second important reason why 

 the theory of mental levels is hard to 

 accept is to be found in the fact that 

 while we know children generally 

 increase in intelligence from birth 

 to maturity, we have never appre- 

 ciated the exceptions." 



There are many theoretical grounds 

 for believing that intelligence develops, 

 and that it can be tested; but in Dr. 

 Goddard's opinion the army ex- 

 perience, in which the results of the 

 tests coincided so well with the actual 

 experience and observation, put the 

 doctrine beyond argument. "With 

 this army experience it is no longer 

 possible for any one to deny the valid- 

 ity of mental tests, even in case of 

 group testing and when it comes to 

 an individual examination by a trained 

 psychologist, it cannot be doubted 

 that the mental level of the individual 

 is determined with marvelous exact- 

 ness." 



Such considerations throw real light, 

 the author thinks, on the search for 

 national efficiency. For the first time 

 Society has an instrument with which 

 to work. If the mental level of every 

 individual in the nation should be 

 determined, it would be possible to 

 apportion the available jobs intelli- 

 gently, preventing good men from 

 wasting their time on inferior jobs, 

 and protecting the public from having 

 mentally inferior persons in positions 

 of responsibility, where they now 

 often are. 



"It is natural to raise the question 

 just here as to whether it would 



1 Human Efficiency and Levels of Intelligence, by Henry Herbert Goddard, director 

 of the Bureau of Juvenile Research of Ohio. Lectures delivered at Princeton Univ., April, 1919. 

 Louis Clark Vanuxem Foundation. Pp. 128. Princeton Univ. Press, 1920. 



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