An explorational investigation of the process of patterning stimuli conditioned to the galvanic skin reaction in man was carried out in 5 experiments with 40 subjects. The main findings are: (1) The incidence of patterning of the galvanic skin reaction in man which results from specific Pavlovian differential reinforcement is small. (2) An index of patterning, based on the ratio of the arithmetical sum of the amplitude of the reaction to 2 separately presented stimulus elements, to the amplitude of the reaction to their simultaneous presentation, is unstable. A possible means of correcting for the distortion of the index employed is suggested. (PsycINFO Database Record (c) 2006 APA, all rights reserved)

One of the most striking things about the present state of the theory of learning and of psychological theory in general is the wide disagreement among individual psychologists. Perhaps the most impressive single manifestation of the extent of this disagreement is contained in 'Psychologies of 1925' [2] and 'Psychologies of 1930' [3]. In these works we find earnestly defending themselves against a world of enemies, a hormic psychology, an act psychology, a functional psychology, a structural psychology, a Gestalt psychology, a reflexology psychology, a behavioristic psychology, a response psychology, a dynamic psychology, a factor psychology, a psychoanalytical psychology, and a psychology of dialectical materialism -at least a dozen.

We must now consider the question of how the tendency to take the long path, which is clearly dominant with many of the animals in Valentine's experiment at the beginning of the 'critical runs,' i.e., that portion of the practice in which the door at E was open throughout each trial, finally gives place to a dominance of the tendency to take the short path. We have shown in the preceding section how occasional choices of the shorter path might be expected to take place through the influence of chance sensory disturbances. But in many cases, at least, the external inhibitions at E would be of relatively infrequent occurrence and the proportion of long-path to short-path choices would still greatly favor the choice of the longer path. Suppose, for example, that we assume only one short choice out of six. A naïve interpretation of the principle of frequency would demand that such a ratio not only would not increase the proportion of shortpath choices but that the short-path choices should steadily decrease until they would entirely disappear. Such an interpretation of the principle of frequency implicitly assumes that frequency is the only principle operative. It is to be doubted whether anyone has ever utilized this principle under such an assumption. At all events, there is reason in this particular case to believe that at least two other factors are also operating simultaneously and in such a way as to oppose and override it. [14] [p. 135]