INDEX 



Hybrid vigor, 344, 347 

 Hysteria, 71 



"Id,"' Freud's, 76 



Illegitimacy, need for revision of laws 



regarding, 193 

 Illinois Experiment Station, 345 

 Immigrants, advisability of intelli- 

 gence tests for, 193 



importance of preventing entrance 

 of low-grade, 194 



importance of promoting entrance 

 of high-grade, 194 

 Immunology, 21, 252 

 Independent Assortment, Law of, 166 

 India, importation of zebus from, 325 



malaria in, 295, 296 



wheat from, 354, 355 

 Indians, 318, 320, 322, 324 

 Individual, rights of, 32, 33 



welfare of, 31, 33 

 Individual differences, 95, lOljf., 124, 



150 

 Individuality of man, 12 

 Induction, Baconian emphasis on, 61 

 Industrial psychologist, 81 

 Industrial research, by-products of, 128 

 Infantile paralysis, characteristics of, 

 251 



methods of control of, 251 

 Infections, pyogenic, 232, 233 

 Inferiority complex, 101, 113 

 Inferiority fixation, 12 

 Influenza, 268 

 "In-group," 42, 43 

 Inheritance, of acquired characters, 189 



of character and personality traits, 

 105 



first law of, 165 



knowledge of Egyptians and Babylo- 

 nians regarding, 163 



of mental characteristics, 182 



of moral traits, 106 



Inheritance, physical basis of, 170 

 second law of, 166 

 of size, 169 



of special abilities, 105 

 Inoculation, 199 



Insanity, early interpretation of, 70 

 Insects, control of introduced species 

 of, through importation of natural 

 enemies, 307, 308 

 role of natural forces in controlling 

 damage done by, 308 

 Instinctive behavior, difference between 



intelligent behavior and, 312 

 Instinctive tendencies, 95, 100 

 Instincts, definition of, 3 



distinction between reason and, 68 

 modern ideas concerning, 46 

 opinion of William James regarding, 



96 

 reaction against older doctrines of, 



37, 97 

 recognition of major, by Hobbes, 59 

 Insulin, 214, 225 



Intellect, difference between masculine 

 and feminine, 89 

 parity of, 189 

 Intelligence quotients, classification 

 according to. 111 

 educational and social significance of, 



111 

 how computed, 110 

 impossibility of raising of, to any 



great extent, 105 

 of negroes, 88 



superiority of average of, among 

 children of well-to-do, 87 

 Intelligence tests, enlargement of field 

 of, 108 

 for immigrants, 193 

 limitations of, 109, 186 

 when reliable, 109 

 showing of, 2 

 use of, in industry, 136 

 when valid, 109 

 Interests, measurement of, 114, 134 



[391] 



