The role of extraversion and neuroticism in human operant conditioning

This study was an investigation of individual differences in human operant conditioning performance. Earlier studies of individual differences in learning phenomena have dealt primarily with the concepts of drive (anxiety, neuroticism) and introversion-extraversion (1-E). Both concepts have received mixed experimental support. However, few studies have been undertaken to investigate the possibility of an interaction between drive and introversion-extraversion. Also, most investigations have used classical aversive conditioning of verbal learning techniques. The present study postulated the existence of four interacting behavioral sub-processes or sub-systems, and suggested that the concepts discussed above involved two of these sub-systems. The anxiety (drive, neuroticism) concept was postulated to involve an activational sub-system, and the introversion-extraversion concept was postulated to involve a perceptual sub-system. Two other sub-systems were postulated, a cognitive sub-system and a response sub-system. Two experiments were performed in which Ss were assigned to groups on the basis of scores on the extraversion and neuroticism scales of the Eysenck Personality Inventory (EPI). The groups were: stable introverts (SI), neurotic introverts (NI), stable extraverts (SE), and neurotic extraverts (NE). The Ss in both experiments took part in an operant conditioning task which required that S^ learn to push one of four keys to obtain a slide change reinforcement on a VI 15-sec., 5-sec. hold schedule This task provided information concerning the efficiency of an S's performance. It was hypothesized that the two dimensions of individual difference, neuroticism (drive) and introversion-extraversion, would interact to determine the efficiency of learning performance in the operant task. As predicted, it was found that the SI and NE groups were efficient learners in terms of the distribution of responses among the four keys and in terms of the number of rewards obtained. The SE and NI groups did not learn efficiently by these criteria. Analyses of variance indicated that these interactive group differences were significant. However, the data indicated that a reinterpretation of the postulated relationship between 1-E and the perceptual sub-system was necessary. The different behavior patterns exhibited by the groups suggested that differential searching patterns were responsible for the observed learning differences. The introverted groups responded on the irrelevant keys(searched) more than the extraverted groups did. However, the neuroticism variable influenced this searching behavior. The interactive group differences suggested that neuroticism pushed the Ss toward increased searching. Thus, the NIs searched constantly, whereas the Sis searched occasionally. Also, the NEs searched almost as much as the Sis (though not as flexibly), and much more than the SEs. The SEs searched minimally. It was proposed that the differential search behavior might best be explained by conceptualizing a scanning program operating on input to the cognitive sub-system. Individual differences in the flexibility and/ or sophistication of this program would give rise to the 1-E dimension. The activational sub-system (neuroticism dimension) would interact with the cognitive sub-system and cause the scan rate to increase with increases in drive level. This would result in increases in searching behavior over S/s normal rate. If :S were a flexible searcher (I) this might cause him to search more than necessary. If were an inflexible searcher (E) this might cause him to search enough to learn more than an inflexible searcher with low drive (SE). It was proposed that the scan program concept could be extended to explain individual differences in paired associate learning and other learning tasks. Such an extension could, if successful, unite studies in diverse fields of the psychology of individual differences.