Story of Psychology - Morton Hunt [180]
Skinner was sometimes self-deprecating about his impact on the world. “In general,” he once said, “my effects on other people have been far less important than my effects on rats and pigeons—or on people as experimental subjects.” That was probably not meant to be taken seriously. What he did mean seriously was the following remark: “I was never in any doubt as to [my work’s] importance.” And he added, on a characteristically perverse note: “When it began to attract attention, I was wary of the effect rather than pleased. Many notes in my files comment on the fact that I have been frightened or depressed by so-called honors. I forgo honors which would take time away from my work or unduly reinforce specific aspects of it.”65
The Impending Paradigm Shift
As behaviorist research accumulated, it became evident to all but the most dedicated adherents of the theory that rats and other laboratory animals frequently acted in ways that the theory could not explain.
For one thing, their behavior often failed to conform to supposedly universal principles of conditioning. “Pigeon, rat, monkey, which is which? It doesn’t matter,” Skinner had written66—but it did matter. Researchers could easily train a pigeon to peck at a disk or a key for food but found it almost impossible to train the bird to flap its wings for the same reward. They could easily teach a rat to press a bar for food but could get a cat to do so only with great difficulty. A rat given sour blue water to drink, followed by a nauseating drug, would thereafter shun sour water but willingly drink blue water; a quail, given the same treatment, would shun blue water but drink sour water. These and scores of comparable findings forced behaviorists to admit that each species has its own built-in circuitry that enables it to learn some things easily and instinctively, others with difficulty, and still others not at all. The laws of learning were far from universally applicable.67
A more serious flaw in behaviorist psychology was that experimental animals kept acting in ways that could not be explained by the neat rate-of-response curves. Many researchers had found, for instance, that at the beginning of an extinction trial an animal would respond to the stimulus with greater vigor than it had during a long series of reinforcements. A rat that had been getting a food pellet each time it pressed a bar would, if no pellet emerged, press the bar with extra force again and again, although according to strict behaviorist theory the absence of the reward should have weakened the response, not strengthened it.68
But of course human beings do the same thing. When a vending machine fails to deliver, the customer pulls or pushes the lever harder a few times, or even hits or kicks the machine, either expressing frustration or acting on the thought that something is jammed and needs an extra jolt. There was no place in behaviorist theory for such internal processes, particularly not for thinking about a problem, yet a number of behaviorists noticed that their rats sometimes behaved as if they were indeed doing rudimentary purposive thinking.
One leading researcher who was aware of this was Edward Chace Tolman (1886–1959), an eminent contemporary of Hull’s and a leading neobehaviorist of the 1930s and 1940s. He observed that after a rat had run a maze a few times, it would pause at a point of decision, look this way and that, take a few steps, and perhaps turn back, all before making its choice and going on. In his presidential address to the APA in 1938, Tolman said it seemed clear that the rat was performing “vicarious trial and error” in its head. “Anthropomorphically speaking,” he added, “it appears to be a ‘looking before you leap’ sort of affair.”69
That was only one of many bits of rat behavior that Tolman concluded could be explained solely in terms of processes going on in the rat’s head. Years