He shut-up hungry cat in a big cage. An attractive piece of food was placed outside the cage. The cat looked at the piece and tried to get at it. It extended its paws through the bars of the cage but the piece was far away.
It tried every part of the cage but all its efforts failed. It thrust its nose through the bars but all in vain. There was a latch inside the cage.
While it was making random movements its paw struck against the latch. The door of the cage opened. Next week the experiment was repeated. The cat made some random movements again but was successful in opening the door sooner than before. In the third or fourth trial there was no random movement.
The cat pushed against the latch and went outside. It learnt the method of opening the door by trial and error.
The experiment sums up the following stages in the process of learning:
In the present experiment it was hunger and was intensified with the sight of the food.
To get the food by getting out the box
The cat was confined in the box with a closed door.
(4) Random Movements
The cat, persistently, tried to get out of the box.
(5) Chance Success
As a result of this striving and random movement the cat, by chance, succeeded in opening the door.
(6) Selection (of proper movement)
Gradually, the cat recognized the correct manipulation of latch. It selected the proper way of manipulating the latch out of its random movements.
At last, the cat learned the proper way of opening the door by eliminating all the incorrect responses and fixing the only right responses.