130 



The JoiRXAL of Hereditv 



12. The alien should be able to ar- 

 range in the order of their weights four 

 cubes of the same size, weighing re- 

 spectively 12, 15, 18, and 21 gms. 



At this point comes the performing 

 test examination. Just as Binet has 

 evolved questions of increasing C(jm- 

 plexity for his French school children, 

 so the United States Public Health 

 Service has evolved a set of jxTfonnance 

 tests of increasing comj^lexity. These 

 are applicable to e\'cry age from three 

 years upward and the jjoint in the scale 

 where an adult stops determines his 

 mental age and the grade of defectives 

 under which he will be classified. At 

 the following ages the tests named 

 under each should be i^erformcd within 

 the time limit stated. 



THE PERFORMANCE TESTS.' 



At three years — 



Should recognize toys and simiilc ol)- 

 jects as such. 



At four years — 



Put some of the pieces in Sequin's 

 formboard and do line "a" of the cube 

 imitation test or touch any two of the 

 blocks. 



At five years — 



Put all the y)ieces in Sequin's fonii- 

 board in three minutes and do line "b" 

 of the cube test or touch any three of its 

 blocks. 



At six years — 



Do the "imbecile" test in five minutes 

 with not over six false moves. Line 

 "c" of the cube test is easy for normals 

 at this age. The construction blocks 

 may be started now; take three blocks 

 all the same shape and build a figure 

 with them, show this to the subject for 

 twenty-five seconds, then break up the 

 structure and ask him to build the same 

 thing. (See Fig. 12.) 



At seven years — 



Do "G" or jigsaw test in three to five 

 minutes. Sequin formboard in thirty 

 seconds and "imbecile" test in less 

 time and with fewer false moves than 

 at six years. Add one l)lock to con- 

 struction blocks. 



At eight years — 



Do Healy frame test in five minutes 

 and imitate line "d" of the cube test. 



At nine years — 



Do diamond frame test, in from five 

 to ten minutes; Healy picture in less 

 than four minutes, Seguin board in 

 twenty seconds and complexity of con- 

 struction blocks may be increased to 

 work with five blocks. 



At ten years — - 



Do "moron" test in less than ten 

 minutes and all the details of the" visual 

 comparison" test (see N. Y. Med. 

 Jour., Sept. IvS. '13) inside of ten 

 minutes. 



At eleven years — 



Do the "e" line of the cube test with- 

 out being shown more than five times. 

 The eight, nine and ten year tests are 

 performed in less time and with fewer 

 mistakes. 



At twelve years — 



Do the "casuist" test in five minutes 

 and any mistakes that are made must 

 be "sensible" and not absurd. (Fig. 14.) 



At thirteen to fifteen years — 



Do "casuist" test in less time and 

 with fewer mistakes than at 12 years; 

 it should be done ^nthout first lacing 

 shown made up or ass^rhblcd. The 

 "feature-profile" test should be cor- 

 rectly done in five minutes. The pic- 

 ture of a shi]) i)asted to a board and cut 

 into ten equal sized jjieces of the same 

 shai)e should ])e ]:)ro])erly assembled in 

 ten minutes. The i)ieccs are all cut 

 vertically. (Fig. 15.) 



This concludes the jK'rfonnance tests 

 after which a story is told the subject; 

 the story contains five details and he is 

 exi^ected to remember three of them. 

 A second story is told which contains 

 an obvious absurdity; if the alien sees 

 this absurdity it counts in his favor but 

 if he does not, that fact does not count 

 against him. 



It is very exident that at the conclu- 

 sion of this examination the physician 

 is in a good position to give his subject 

 a mental rating, provided of course that 

 he tempers the tests with jilenty of 

 everv dav common sense. 



' Dr. Knox is about lo publish a more complete account of the special scale for thi- measure- 

 ment of intelligence, classification of defectives, and performance tests, with report of cases, in 

 i\\c Journal of the American Medical Association. He will be j;lad to send interested members 

 of the American (ienelic Association the exact reference, or a reprint of the more extended 

 discussion of tlie subject. The illustrations of performance tests publisheil hercvith illustrate' 

 the general character of all, but are, of course, only a few of the whole numbiT used. — The Editor. 



