A HEALTHY MIND 



231 



found that their intelHgence, that is, their I.Q., ranged from sixty- 

 two to one hundred and four. This work could have been done 

 efficiently by persons with scores of ninety. C. W. Waugh gave 

 intelligence tests to eighty-two street-car motormen and con- 

 ductors. The investigation showed a range of intelligence from 

 sixty-five to one hundred and ten. A score of eighty to ninety 

 was probably sufficient for a person to do this type of work well. 

 Those with higher intelligence did not do more work nor do it 

 more efficiently than those of lower intelligence. One of the 

 men scoring low had a serious accident on his car. It is a 

 fairly well-established fact that a motorman or conductor with 

 an I.Q. of less than seventy-five is, as a rule, an unsafe risk. 

 There is a big economic loss, to the company as well as the indi- 

 vidual, in employing men of high intelligence to do work that 

 could be done as well by men with less intelligence. Educators 

 should direct those students of highest I.Q. ratings into lines of work 

 which will require superior intelligence, and those of mediocre in- 

 telligence, low I.Q., into lines 



of work for which they are 

 fitted. At present, there is 

 too great a waste of mental 

 ability by men and women 

 filling positions that could be 

 competently filled by persons 

 of less ability. Students 

 studying professional subjects 

 should be those of fairly high 

 intelligence rather than 

 merely those with money 

 enough to pay for such train- 



nucleus. 



c^toplasm>r-f 



A tired nerve cell (B) shows fewer chromatic 

 granules than a rested nerve cell (A). 



mg. 



A healthy mind. The nervous system, like the other systems 

 of the body, is kept in the best possible condition if the body is 



