144 THE SOCIAL LIFE OF ANIMALS 



As might be anticipated, the difficulties of human 

 experimentation being what they are, it is hard to 

 collect accurate information on this point. Much 

 depends on the comparative accuracy of the sam- 

 pling, and also on more subjective factors, such as 

 the attitude of the teacher and of the students toward 

 large and small classes. There is also a factor which I 

 have not seen mentioned in the literature on the 

 subject, the effect on the student of realizing or sus- 

 pecting that he is an object of experimental interest, 

 an educational guinea pig. This stimulus is more 

 likely to be potent, in my opinion, when the student 

 is a member of a class which is unusual in size. 



In the more careful studies, results of which have 

 been published, the class numbers have ranged from 

 "small" through ''medium" to "large." The "small" 

 experimental classes apparently have about twenty 

 to twenty-five members; this represents a more usual 

 experience to the student, and he is more likely to 

 be conscious of class size when he is a member of a 

 large class of seventy-five or more than when he is in 

 a small class or a medium-sized one of thirty-five to 

 forty. The sizes that are counted "large" or "small" 

 vary greatly, sometimes in the same experimental 

 treatment, so that frequently the comparisons are 

 between larger and smaller classes, both medium in 

 size, rather than between real extremes in numbers. 



