The effect of working memory capacity limitations on the intuitive assessment of correlation: Amplification, attenuation, or both?

This article challenges Yaakov Kareev's (1995a, 2000) argument regarding the positive bias of intuitive correlation estimates due to working memory capacity limitations and its adaptive value (see record 1995-39555-001 and record 2000-15248-009). The authors show that, under narrow window theory's primacy effect assumption, there is a considerable between-individual variability of the effects of capacity limitations on the intuitive assessment of correlation, in terms of both sign and magnitude: Limited capacity acts as an amplifier for some individuals and as a silencer for others. Furthermore, the average amount of attenuation exceeds the average amount of amplification, and the more so, the smaller the capacity. Implications regarding the applicability and contribution of the bias notion in this context and the evaluation of the adaptive value of capacity limitations are discussed.