Cole, working with raccoons, used a simple apparatus in which a number of levers served to present color stimuli. The color, the order or the number of visual stimuli presented indi cated food. The animals learned to expect food as a reward on presentation of a certain visual stimulus or series of such stimuli. They even discovered how to work the levers for them selves in order to cause the desired stimuli to appear. Cole considers their behavior as imagi native, that is, indicating the functioning of ideas.
For the purpose of exhibiting the reactive tendencies or capacities of different kinds of animal, Hamilton devised an ingenious method and apparatus. He places his subject, animal or man, in a room on one side of which there are four doors, all closed. According to a prear ranged scheme, one of these doors will open when approached by the animal and allow it to escape to food and freedom. In that particular trial, all of the other doors are locked. In the next trial, the door which previously was un locked is locked, and some one of the other three doors will open when approached. In each 100 trials, each door is unlocked 25 times.
The question is, How will any animal meet this practical situation, ideationally or other wise, effectively.or ineffectively? As Hamilton has shown, there are various degrees of ade quacy or effectiveness of response possge These may be spoken of as types of react.• tendency.
The method of Hamilton may be used tematically to obtain knowledge of the reacti tendencies, that is, ability to solve a part type of problem in various types of animal has studied cats, dogs, horses, monkeys, gopher, rats and human subjects), the same type a4 animal at various stages of development, as for example, in infancy, childhood, adolescence and so on, or in various conditions of disease or defectiveness.
By Hunter, yet another ingenious means c= testing for ideas has been devised and applied It is called the delayed reaction method. The apparatus is so arranged that an animal may escape from confinement in a box and obi, the reward of food by selecting and passim through a certain exit passage. The particula: passage to be selected from among others ic given trial is indicated by a light Many an mats, such as mice, cats, rats, raccoons, quick; learn to go directly to the passage which is illuminated. This habit having been definitely
established, the experimenter, before permitting the animal to make definite choice of a par ticular passageway, turns off the light_ It then becomes necessary for the animal to choose M path in the absence of the indicating stimulus The question in the mind of the experimenter ir this method is, Can a given animal correctly choose its way of escape on the basis of a signal which no longer exists, unless it be in its own consciousness or brain? If so, how long after disappearance of the indicating light is corm response possible, and what is the nature of the process by which choice is made? It has been found that rats can make their choice correctly after being forced to wait for 10 seconds; raccoons, after a delay of seconds ; dogs, after 300 seconds ; children, after 25 minutes. And it is conceivable that the human adult might respond properly even alter an interval of many months, were the matter of extreme importance.
This ability to respond appropriately to stimuli or situations remote in time or space is indicative of what the psychologist terms im ages or ideas, the representative conscious process. Thus, the method of delayed reactions tends to throw light on the ideational character of animal behavior.
Yet another method of studying the associa tional and ideational behavior of animals in volves the presentation of problems of various sorts which demand ingenuity and This is called the problem or puzzle box method_ It was first extensively and systematically used by Thorndike.
The animal is placed in a box from which it may escape to food, which is visible outside. by operating some simple mechanism as, for example, a latch, bolt, lever or pedal. It is the observer's purpose to learn- whether the animal can discover the relation of means to ends, or having accidentally happened upon the correct act or series of acts, can skillfully and with ap parent insight perform the necessary act when next required to.
Thorndike's discussion of how cats and dogs learn to solve simple and novel problems and Kinnaman's similar studies on monkeys intri cate that these animals learn very largely by ?rocess of trial and error. They give slight ;round for the assumption that free ideas exist ?nd influence behavior.