Effects of Anxiety Level and Extraversion-Introversion on Probability Learning

Abstract

Suppose an individual has to predict which of two events will occur on each of a series of tries, and one of these events is more likely than the other although boch in fact occur in a random sequence. How often will the rare event be predicted? Two factors might conceivably make for a high rate of predicting the rare event. It is the purpose of this study to separate them and examine their possible relationships to aspects of personality in an older sample. A high rate of predicting the rare event will result if the person assumes there is some pattern to the rare event's occurrence, and tries to solve the of accurately predicting when the rare event will occur (the problem approach). For such a person, trying to catch the rare event's occurrence is a challenge which he accepts: being correct in predicting the rare event is more imporcant to him than being correct in predicting the frequent event. On che other hand, a high rate of predicting the rare event also will result if the person simply isn't sensitive to the infrequency of the rare event and hence treats it as if it occurs more often than it does (the 50:5OW approach). Although boch problem and 50:50n approaches lead to more frequent prediction of the rare alternative, the former is a much more thoughtful approach to che task than the latter. Can we discinguish the two in terms of some additional response measure? Latency of predicting the rare alternative seems to provide a method. If high frequency of choosing the rare alternative is due to the problem approach, then choice of the rare alternative should be preceded by a longer latency than choice of the frequent alternative: S should be especially thoughcful before predicting the rare event since its accurate prediction is the challenge for him; it is the rare event with which his hypotheses specifically are concerned. Predicting the frequent event, on the other hand, is more likely to be correct and hence poses less of a problem. If, on the other hand, high choice frequency for the rare event is due to the 50:50 approach, then S should be about as fast in predicting the rare alternative as he is in predicting the frequent one since he is insensitive to the difference between [hem. Although a frequency measure alone, then, is not sufficient to distinguish [he problem and 50:5OP' approaches, measuring latencies as well as frequencies seems co provide a way of making this discrimination. We hence may 'This investigation was supported by a research grant (M-2269) from the National Institute of Mental Health, Public Health Service, conducted under the auspices of The Age Center of New England, Inc. Grateful thanks are due Marguerite Braun, Leonard R. Green, and Lynne Hamilton, for aid in data analysis.