Contingency judgment: Primacy effects and attention decrement

Abstract

Subjects made judgments concerning the strength and direction of the contingency between two dichotomous variables in a situation in which no contingency actually existed. The judgments exhibited a significant primacy effect. The effects of warning and not warning the subjects that they would be required to recall the frequencies of observed event co-occurrences implied that this primacy effect was due to `attention decrement' ([Anderson, 1981]). According to this hypothesis, attention to contingency-relevant information diminishes after the subject is exposed to only a small portion of the available information.