240 Psychology and Sociology of the Todas, etc. 



Europe, but the Todas show the highest recorded frequency of this condition 

 in any race. By means of the genealogies preserved by the Todas the 

 relationship between the colour-blind people could be traced, and a body of 

 material was obtained which illustrates the mode of hereditary transmis- 

 sion of the defect. 



The Todas were found to be subject to various geometrical-optical illusions : 

 and quantitative observations were made on the illusion of compared vertical 

 and horizontal lines and on the Miiller-Lyer illusion. The Todas are 

 subject to the former in a greater degree than English observers, and to 

 the latter in a smaller degree. The two illusions differ in nature : the 

 former is probably largely physiological in origin, and is neutralised by 

 the experience of civilised life, while the latter is more strictly psycho- 

 logical in character ; and the different reaction of the Todas to the two 

 illusions is in accordance with this difference in their nature. 



In every measurement the degree in which the individuals of each 

 race differed from one another was studied ; and a mass of material was 

 collected for the study of variability in the reaction to psychological tests, 

 and for the analysis of the complex conditions upon which the coefficients of 

 variation depend. 



On comparing the observations of Todas, Papuans, and Englishmen, all 

 tested by the same methods, and chiefly by the same experimenter, it is 

 found that there is some evidence of a correlation between the decree of 

 general intellectual development and certain simple mental properties or 

 activities which can be tested by experimental methods. In general 

 intellectual development the Todas occupy an intermediate position between 

 Papuans and Englishmen, and a similar intermediate position is occupied by 

 them in connection with many of the tests.* 



The social and religious institutions were also studied. The sociology was 

 investigated largely by means of the genealogical method,f and the system 

 of kinship, the complex marriage regulations and the laws of inheritance 

 and property were worked out in detail. 



The Todas were found to possess a highly elaborate religious ceremonial 

 of which only brief sketches had previously been jrablished, while many 

 ceremonies had wholly escaped observation. In consequence, much time 

 was devoted to the detailed investigation of this ceremonial and of the other 

 features of the Toda religion. Evidence is given that this religion is one 

 which has undergone degenerative changes, and some evidence is advanced 



* A full account of the senses of the Todas will be published shortly in the ' British 

 Journal of Psychology,' vol. 1, Part IV. 



t ' Journ. Anthrop. Inst., 5 1900, vol. 30, p. 74. 



