Bertrand Russell: The Analysis of Mind

2. LECTURE II. INSTINCT AND HABIT (continued)

The process of learning, which consists in the acquisition of habits, has been much studied in various animals.* For example: you put a hungry animal, say a cat, in a cage which has a door that can be opened by lifting a latch; outside the cage you put food. The cat at first dashes all round the cage, making frantic efforts to force a way out. At last, by accident, the latch is lifted. and the cat pounces on the food. Next day you repeat the experiment, and you find that the cat gets out much more quickly than the first time, although it still makes some random movements. The third day it gets out still more quickly, and before long it goes straight to the latch and lifts it at once. Or you make a model of the Hampton Court maze, and put a rat in the middle, assaulted by the smell of food on the outside. The rat starts running down the passages, and is constantly stopped by blind alleys, but at last, by persistent attempts, it gets out. You repeat this experiment day after day; you measure the time taken by the rat in reaching the food; you find that the time rapidly diminishes, and that after a while the rat ceases to make any wrong turnings. It is by essentially similar processes that we learn speaking, writing, mathematics, or the government of an empire.

* The scientific study of this subject may almost be said to begin with Thorndike's "Animal Intelligence" (Macmillan, 1911).

Professor Watson ("Behavior," pp. 262-3) has an ingenious theory as to the way in which habit arises out of random movements. I think there is a reason why his theory cannot be regarded as alone sufficient, but it seems not unlikely that it is partly correct. Suppose, for the sake of simplicity, that there are just ten random movements which may be made by the animal--say, ten paths down which it may go--and that only one of these leads to food, or whatever else represents success in the case in question. Then the successful movement always occurs during the animal's attempts, whereas each of the others, on the average, occurs in only half the attempts. Thus the tendency to repeat a previous performance (which is easily explicable without the intervention of "consciousness") leads to a greater emphasis on the successful movement than on any other, and in time causes it alone to be performed. The objection to this view, if taken as the sole explanation, is that on improvement ought to set in till after the SECOND trial, whereas experiment shows that already at the second attempt the animal does better than the first time. Something further is, therefore, required to account for the genesis of habit from random movements; but I see no reason to suppose that what is further required involves "consciousness."