CONCEPTUAL THOUGHT l6l 



of one long continuous process. They represent an orderly 

 and gradual unfolding of a learning and thinking process. 



Children between the ages of two and five were chosen 

 because they had had a minimum of previous training and 

 were given these same tests. Most of the children made 

 many errors and only gradually learned to solve the prob- 

 lem in one trial. The author found that children learned 

 more rapidly than monkeys but that they made the same mis- 

 takes. There were cases where the smartest monkey learned 

 more rapidly than the dullest child. 



This kind of progressive learning leads to the formation 

 of a "learning set." Here an organized set of habits is 

 learned which enables the subject to deal effectively with 

 each new problem of a particular kind. An animal finally ac- 

 cumulates many learning sets in the trial-and-error solution 

 of problems which face it throughout its hfe. A great host 

 of sets may furnish the human mind with its raw material. 



In the same series of experiments monkeys and children 

 were trained in much more complex problems, one being a 

 switch-over of the above. An attempt is made in this type of 

 reversal to confuse the subject; the previously correct ob- 

 ject is now the incorrect object. Again, errors by both the 

 monkeys and children are numerous, but gradually the er- 

 rors decrease until finally at the first reversal trial there is a 

 perfect performance: a single failure will lead the subject to 

 shift from the object which had been previously rewarded 

 many times to the object which has never before been re- 

 warded. Subjects were also offered a choice of three objects, 

 two of a kind and one odd (say, two building blocks and a 

 funnel) , and it was the odd that was rewarded. After picking 

 the odd funnel had been learned the problem was reversed: 

 two funnels and one block are used, the reward now being 

 in the block. In time the animal learns the subtle distinction 

 that the shape of the object is not important, but rather its 

 relation to the two other objects. It learns to "think" of 



