CHAPTER 13 – FOUR NEOBEHAVIORISTPSYCHOLOGISTSDr. Nancy AlvaradoFour Neobehaviorists The four neobehaviorists described in this chapter (Tolman, Guthrie, Hull, Skinner) accepted Watson’s:  Rejection of consciousness His definition of psychology as the science of behavior His insistence on objective, observational data. These four had similarities but also many important differences from each other. As a result, the Behaviorist movement was extremely productive in terms of theory and research.Edward Chace Tolman (1886-1959) Tolman grew up in Newton MA and went to MIT, graduating with a degree in electrochemistry. William James “Principles of Psychology” changed his life – he went to Harvard & studied with Munsterberg. Tolman was troubled by why introspection was so rarely used in his lab, although taught as a methodology. A class with Yerkes focused his attention on behavior. He spent a month in Germany with Koffka & was influenced strongly by Lewin. He taught at Northwestern, then at UC Berkeley.Edward Chace TolmanTolman Hall at UC BerkeleyTolman’s Cognitive Behaviorism At Berkeley, Tolman taught comparative psych using Watson’s book as a text. He disagreed that rat behavior was mechanistic, considering rats intelligent and purposeful. He believed rats learned the general layout of a maze, forming a “cognitive map.” He developed a “molar behaviorism” concerned with purpose and cognition – both excluded by Watson. However, his book “Purposive Behaviorism” began with an attack on mentalistic psychology.Rats Have Purpose Tolman & his students showed that: Rats have preferences and run fastest for rewards they like better (bread and milk not sunflower seeds). Rats are disappointed if they get a less valued reward previously expected due to training. Monkeys were similarly disappointed by a lettuce leaf in place of a banana. Rats use prior experience when unrewarded to increase their behavior later when rewarded –latent learning. What is a reward critics asked?Latent Learning ResultsRats Have Insight Tolman & Honzik gave unrewarded rats experience with a complex maze, then found that they use the shortest route when rewarded. Law of least effort – given a choice of several paths, rats use insight to find the one requiring least effort. Rats remember where something is located, not a series of turns (responses).  Two groups – one (Place) always found food in the same place; the other (Response) always found food by turning in the same direction. Place rats learned faster.Tolman’s MazesS2S1F1F2curtaincurtainTolman’s Theoretical Model Tolman published over 100 papers and 2 books. He proposed a model of independent, intervening and dependent variables that is widely used in experimental psychology. IVs are manipulated by the experimenter and influence intervening variables such as appetite or motor skill. Subject IVs (age, heredity) are held constant. DVs (running speed, number of errors) are measured by the experimenter.Tolman’s General Concerns Tolman tried to relate his rat-runner’s psychology to broader human problems such as aggression or war. In 1949, he supported younger colleagues required to take a loyalty oath, refusing to take it himself. Tolman was APA President in 1937 and a member of the National Academy of Sciences. Tolman liberated Behaviorism from Watson’s methodological and theoretical constraints. Contemporary behaviorists no longer view animals as passive, mechanical systems but active info processors.Edwin Ray Guthrie (1886-1959) McDougall classified Behaviorists as “strict, near or purposive” types. Guthrie was “near.” Guthrie graduated in math, then studied psychology at Univ. of Nebraska with Wolfe. He finished his Ph.D in philosophy with Singer at Univ. of Penn.  He doubted that deduction could lead to an understanding of the human mind. He taught math briefly then accepted a position at Univ. of Washington, transferring to psychology in 1919 and becoming a professor in 1928.Edwin Ray GuthrieLearning Through Contiguity Guthrie proposed that “Stimuli which accompany a response tend, on their recurrence, to evoke that response.” The simplicity of this was appealing as the ideas of other theorists became increasing complex. Association through contiguity goes back to Aristotle, Bain & Hartley (British Associationists). Reward does not cause learning – it protects it against unlearning because the situation changes. Guthrie also proposed single-trial learning.Guthrie’s Approach Guthrie was able to provide clever explanations of a variety of learning phenomena (effects of reward and punishment, practice, trace conditioning). Punishers elicit actions – these actions are learned. Improved behavior occurs with practice because the constituent movements become better with repetition. “Learning does not disappear with lapses in time but due to new learning which erases the old.” Sleep prevents learning of new associations.Pavlov’s Criticism of Guthrie To explain delay & trace conditioning, Guthrie suggested that the stimuli accompanying salivation are not the CS (bell) but the orienting response (listening, turning head, pricking up ears). In reply, Pavlov wrote and angry response -- “The Reply of a Physiologist to Psychologists,” his only paper published in an American psychology journal. He said the “listening” response was nonexistent because dogs were not alert during the trace gap and because the orienting response quickly disappears –there are no mysterious latencies in the nervous system.Guthrie’s Examples Dogs encountering meat with embedded mousetraps become suspicious of the meat because of the almost perfect contiguity. A daughter made to re-enter and hang up her coat changes behavior because of the new association. Other examples of pastor’s horse trained to lunge when he said “whoa” (which means stop); breaking horses with successive weight on its back (contiguity). Signals to smoke (finishing a meal, starting work).Cats in a Puzzle Box Performing 800 escape responses, Guthrie observed that cat responses were highly stereotypical (the same each time). He suggested that cats had learnedto associate that specific movementwith escape from the box. Critics suggested the movementwas stereotypical because