Kathy Busse, age 17, of Casper, Wyo., for her question:
WHAT IS COMPARATIVE PSYCHOLOGY?
Comparative psychology is the psychology of animals the study of their intelligence, needs, sensory capacities and characteristic ways of behaving.
Animals are studied in such special environments as laboratories and zoos, as well as in their natural environments. The natural environment is of particular interest because the animal is equipped to survive there.
In the laboratory, selected features of the environment are varied systematically and their effects on behavior are measured precisely. Although naturalists sometimes criticize laboratory studies as artificial, implying that the information obtained is not to be trusted, this criticism is misleading.
Some of the most penetrating insights into the behavior of animals have been achieved by making radical changes in their natural environments. For example, rearing a chick in complete isolation shows that social stimuli are necessary for its normal development.
Often animals are studied simply because of curiosity about them. But in comparative psychology, the experiments with animals are often used to provide information about man under conditions in which human experimentations are not practical.
The results of animal experiments can be applied to man only if it can be assumed that experiments with human beings would yield the same results. Whether they would or not is uncertain. The assumption that they would can sometimes be justified because of the structural resemblances between man and the higher animals and the similar results of experiments that can be performed with both men and animals.
A great deal is learned about men simply by asking them questions, but that method is not available in the study of animals.
Comparative psychologists are particularly interested in the ability of animals to learn.
If the ability of a monkey to detect small differences in brightness is to be determined, the animal first must be trained to respond differently to objects of different brightness. One method is to show the animal a pair of differently illuminated panels and to reward it with a raisin for pressing the brighter panel.
After the monkey has learned to choose the brighter one, the experimenter gradually reduces the differences in brightness between the two panels until wrong choices become as frequent as correct ones. At that point, the limit of the animal's capacity to discriminate has been reached.
Comparative psychologists point out that any single instance of behavior is the product of several different psychological processes. A monkey's performance in the experiment on brightness discrimination involves more than its ability to detect a difference in brightness. Essential also are an interest in raisins and an ability to learn how to get them in the experimental situation.
A comparable experiment could not be performed with a jellyfish because the jellyfish is incapable of learning.