9° 



THE POPULAR SCIENCE MONTHLY 



An idiot, according to this classification, can not reach a degree of 

 mentality beyond that of a normal child of three years, an imbecile be- 

 yond seven and a moron beyond twelve. This has been determined by 

 means of a series of tests. 



Mental and Physical Tests 



There have been several attempts during the past fifteen years to 

 formulate a series of graded tests which will evaluate children's span of 

 intelligence and measure mental defects by means of comparison with 

 posited norms. Binet has been at work longest trying to formulate 

 such tests and with some success and while the Vineland and Lincoln 

 institutions are adopting the Binet and Simon tests for work with 

 feeble-minded children, the University Elementary School, of the Uni- 

 versity of Chicago, and the Psychopathic Institute, of the Chicago 

 Juvenile Court, are establishing norms for normal American children. 



Fig. 10. Psychojietee. The psychic galvanometer or psychomefer, which is 

 used to detect delicate physiological changes which accompany the emotional ex- 

 periences of children. This apparatus is also used in psychological methods for 

 detecting crime, although the nature of the phenomena giving rise to the galvano- 

 metric deflections is still an open question. 



The Binet and Simon tests throw little light on the moral or physical 

 nature of the child, and they do not allow for sense defects, which would 

 naturally affect a child's standing, even though normal in other re- 

 spects. The latest edition of these tests takes into account the age of 

 the child, and eliminates almost entirely the factor of training by 

 measuring what the child learns fortuitously. They thus form a 

 " measuring scale for intelligence " and are of direct value and interest 

 to all parents and teachers of normal as well as backward or defective 

 children. The fifty-seven tests cover the period from three to twelve 

 years, and if a child succeeds in the tests derived for his age, he is 

 normal ; if he can succeed only in the test devised for a child one year 



