Story of Psychology - Morton Hunt [161]
One he called the Law of Effect. The puzzle box was a stimulus that elicited a number of responses; the effects of most were “annoyers” (failures to escape or to reach the food), but one was a “satisfier,” which yielded both escape and food. Annoyers and satisfiers selectively “stamp in” (or, as Thorndike later said, “reinforce”) certain stimulus-response connections and weaken or eliminate others. The effect of any action thus determines whether it becomes the response to a given stimulus or not.
The second law he called the Law of Exercise. Other things being equal, “a response will be more strongly connected to a stimulus in proportion to the number of times it has been connected with that situation and to the average vigor and duration of the connection.”
Thorndike’s monograph had an immediate effect on psychological thinking. It lent new, research-based meaning to old philosophic notions of associationism; it provided convincing support for C. Lloyd Morgan’s dictum against assuming higher mental functions if lower ones could explain behavior; and it established animal experimentation as the pattern for most learning research for the next half century.
While later researchers (and Thorndike himself) would somewhat modify the Law of Effect and greatly qualify the Law of Exercise, the two laws became the basis of behaviorist psychology, human as well as animal. For although human behavior is vastly more sophisticated than that of cats, behaviorists argued that it is explicable by the same principles; the difference, Thorndike said, is simply that “the number, delicacy, and complexity of cell structures” in the human brain make for a corresponding “number, delicacy, and complexity of associations.”9 He even held that the reason human culture develops so slowly is that it is the result of trial-and-error learning with accidental success, the same method by which animals acquire associations.
Ivan Pavlov (1849–1936), a very different breed of scientist, was a research physiologist who spent the first half of his career investigating the digestive process. It was in the course of this work that he noticed the odd phenomenon of the salivating dog, and he spent the second half of his career studying what he called “conditioned reflexes.”10 From first to last he considered conditioning a physiological rather than a psychological process, and although the laws of conditioning became as basic to behaviorism as the laws of learning and effect, he had so poor an opinion of psychology that he threatened to fire anyone in his laboratory who used psychological terminology. To his dying day he insisted that he was not a psychologist but a physiologist studying brain reflexes.
Pavlov was born in a central Russian farming village. His father was the local Orthodox priest, his mother the daughter of a priest, and Pavlov planned to follow in the family tradition. Czar Alexander II had recently made free education available to gifted but poor students; Pavlov qualified on both counts, and was educated in a primary school and a seminary. But while he was at the seminary he read Darwin’s Origin of Species and the Russian physiologist Ivan Sechenov’s Reflexes of the Brain, and underwent something akin to a conversion. Abandoning his plans for the priesthood, he quit the seminary to study natural science at the University of Saint Petersburg (again thanks to the Czar’s largesse), where Sechenov was a professor of physiology.
Pavlov graduated in 1875 with a brilliant record and went on to study medicine, but his goal was research, not practice, and he had to support himself—and, after 1881, a wife—on ill-paid assistantships. At that time, Russia offered far fewer opportunities to young scientists than did the Western countries, and despite Pavlov’s extraordinary talent and his impressive research studies in physiology, he could eke out only a marginal existence for many years.
He was too absorbed in his work, however, to be concerned about the exigencies