Verbal Factors in the Discrimination Learning of Children

Most so-called stimulus-response theories in psychology are based on principles established in research on conditioning. The last 25 years has witnessed an increasing influence of such theories on research programs dealing with discrimination learning. That is, conditioning principles have been applied to discrimination learning data in an attempt to explain or account for the phenomena discovered in the discrimination learning situation. The Spence theory, published in 1936, was the first systematic attempt to apply conditioning principles to discrimination learning. For the first Io or 15 years of this quarter century, the application of such theories was largely restricted to the discrimination performance of infrahuman subjects. Recent years have seen a marked increase in the number of applications of stimulusresponse theories to the discrimination learning of human subjects, and, in particular, to that of children. Since even behavioristic psychologists do not ignore introspection as a potential source of information, it was inevitable that behavior theorists would make increasing use of the notion of response-produced stimulation in their attempts to apply conditioning principles to human learning. The logical or philosophical justification for the use of such concepts was laid many years ago in the writings of such people as Tolman and Hull. These writers, and others, rejected the Watsonian doctrine that mentalistic, or, more precisely, mentalistic-sounding concepts could not appear in the vocabulary of psychology. They insisted, however, that such concepts be introduced only after having been defined by means of terms which referred to public phenomena. The empirical utility of such a view was demonstrated in several experiments conducted in the 1930's. Experiments by Leeper (1935) and Hull (1933) demonstrated that rats could discriminate on the basis of being hungry or being thirsty, which led to the notion of drive stimuli (SD). Shipley (1933, 1935), in his research on mediated or secondary generalization, demonstrated that stimuli resulting from a subject's response can serve as a cue to which other responses can be conditioned. This led to the concept