The Concept of Correlation in Adults

In the first of two experiments on the concept of correlation in adult subjects, the subjects' frequency estimates and inferences of relationship were studied relative to five different 2 × 2 distributions, each presented in a fixed sequence. In experiment II, the subjects' spontaneous strategies in subdividing and analyzing one 2 × 2 distribution were studied in a free situation. It is concluded that adult subjects with no statistical training apparently have no adequate concept of correlation (based on the ratio of the two pairs of diagonal frequencies), and that, in so far as they reason statistically at all, they tend to depend exclusively on the frequency of ++ cases in judging relationship. The need for studies involving ordinal scale and fully quantified variates is stressed.