Wolfgang Köhler
Köhler recognized that, like humans, there is a great deal of individual differences in intellect. Chimps showed that they were able to grasp the objects around them in a variety of fashions. This is incorporated in their everyday playing behaviours. For this reason, it was not necessary to use experimental tests to introduce chimps to handle matter. In his book, Köhler describes how the apes use their hands: “large, powerful and flexible hands are natural links between himself and the world of things, and he attains the necessary amount of muscular force and co-ordination at an earlier age than the human child” Köhler (1925).