890 



SCIENCE. 



[N. S. Vol. XIX. No. 493. 



THE NEW YORK ACiDEMY OF SCIENCES. 

 SECTION OF ANTHROPOLOGY AND PSYCHOLOGY. 



The regular meeting of the section was held 

 on March 28 in conjunction with the New 

 York Branch of the American Psychological 

 Association. The afternoon session was held 

 at the Psychological Laboratory of Columbia 

 University, the evening session was held as 

 usual at the American Museum of Natural 

 Pistory. The program was as follows: 



Mental Resemblance of Twins: Professor E. 



L. Thorndike. 



A report was made on the general results of 

 a comparison of twins in tests of attention, 

 perception, association, rate of movement, 

 addition, multiplication and stature. The re- 

 semblances as measured, by a 'rough, prelim- 

 inary method, were about .75. The amount 

 of this resemblance that should be attributed 

 to similarities in home training was appar- 

 ently slight. There was no evidence in the 

 results to support the theory that twins fall 

 sharply into two species, those very closely 

 alike and those no more alike than ordinary 

 brothers and sisters. 



Measurements of the Mentally Deficient: Miss 



Naomi Norsworthy. 



The paper was a report of some work done 

 among one hundred and fifty mentally defi- 

 cient children in two state institutions for the 

 feeble-minded and in two of the special classes 

 organized in the New York schools. The 

 measurements taken were physical, such as 

 height, height and temperature, tests of ma- 

 turity, as perception of weight and of form, 

 tests of memory and tests of intelligence or 

 the ability to deal with abstract ideas. The 

 main conclusion reached was that the differ- 

 ence between idiots and people in general is 

 less than has been commonly supposed, and is 

 a matter of degree rather than of kind. 



Color Contrasts: Dr. E. S. Woodworth. 



Dr. Woodworth presented a modification of 

 Hering's binocular demonstration of the 

 ' physiological ' origin of simultaneous con- 

 trast. If monocular fields of different colors, 

 with a gray spot on each, be combined by the 

 stereoscope, each gray retains the contrast 

 color suitable to its own field, however the 



conscious background may vary as the result 

 of fusion or rivalry of the two fields. The 

 demonstration is readily extended to cover 

 brightness contrast, by placing gray spots on 

 white and black fields which are combined as 

 before. To show that these effects are not 

 the result of a binocular mixture of the gray 

 with the opposite field, a number of gray spots 

 may be scattered over one field, and the other 

 field made particolored; the gray spots appear 

 all alike, or nearly so, though binocular mix- 

 ture would have made them differ. 



New Apparatus and Methods: Professor J. 



McKeen Cattell. 



(1) Kymographs were exhibited in which 

 typewriting ribbons were applied to secure 

 the records. Electro-magnetically moved 

 points strike the paper tape, whose rate of 

 movement may be adjusted, and a record is 

 left by the slowly moving typewriter ribbon. 

 Two forms were exhibited, in one of which the 

 kymograph was driven by an electric motor 

 and in the other by clock-work. In the latter 

 the clockwork could be started and stopped by 

 an electric current by an observer in' another 

 room. The kymographs, while not especially 

 suited for drawing curves, are much more con- 

 venient than smoked paper or siphon pens for 

 time records, such as rhythms, conflict of the 

 visual fields, after-images, etc. (2) Instru- 

 ments were shown by which a number of faint 

 clicks could be given at intervals of a sec- 

 ond for testing sharpness of hearing and de- 

 fective hearing. Instead of giving the ob- 

 server a continuous sound, such as from the 

 ticking of a watch, two, three, four or five 

 faint sounds are made, and the observer is 

 asked how many he hears. By this method 

 errors from the common illusion in the case 

 of faint sounds are avoided. (3) A method 

 was exhibited for testing color blindness by 

 the time it takes to distinguish one color from 

 another. By the normal individual red can 

 be distinguished from green in about the same 

 time as blue from yellow, but it takes longer 

 to distinguish red from orange. If the ob- 

 server belongs to the red-green class of the 

 color blind, he can distinguish blue from yel- 

 low as quickly as others, but not red from 

 green. An instrument was shown by which 



