ABSTRACT
Common observation shows that children differ greatly in their mental make-up and psychology proves these differences to exist in the case of all mental qualities and to be of the utmost practical importance. In the physical characteristics of the sense and motor organs, in the strength of instincts and capacities, in the nature of their previous experiences and inborn and acquired interests—no two children are exactly alike and any one school class will show extensive differences. The same stimulus cannot be expected to produce exactly the same response in any two and will rarely produce anything like the same response from all.
