ABSTRACT

In 1927 the Gestalt psychologist Wolfgang Kohler conducted a classic experiment in animal problem solving (Kohler, 1927). Chimpanzees were placed in a caged area outside of which was a banana. Nearby were some sticks and Kohler was interested to know whether the chimps would make use of the sticks as a rake to haul the banana into the cage. The chimps were able to use the sticks effectively in other situations too: as a pole to climb up to get fruit, and as a club to knock fruit down from a tree. Even more impressively, the chimps learnt to use a pile of boxes as a ladder to retrieve fruit. They also showed remarkable generalisation. Thus when the boxes were removed they would find other objects to climb up on. In one case, a chimp known as ‘Sultan’ led Kohler himself under the hanging banana and used the unsuspecting researcher as a ladder.