Abstract

The primary purpose of the present study IS to figure out the reason why the illusory correlation phenomena differ in individual and group targets. Hamilton(991) proposes that a distinctiveness-based illusory correlation occurs with a group target, whereas a salience-based illusory correlation occurs with an individual target. because of the expectancy to form a consistent and unified impression to the individual target. We hypothesize that whether or not the attention is given to the target and whether the judgmental encoding is made in an on-line fashion or memory-based fashion might be responsible for the difference. To prove this, a completely randomized 2(attention, no-attention) by 3(on-line, memory-based, control) by 2(individual, group) experiment was conducted with 180 subjects. Dependent variables included target assignment. frequency estimates, and performance evaluation. Results showed that when no attention was given, there was a difference between on-line and memory-based conditions with a group target, but there was no difference between the two with an individual target, as expected. On the other hand, when the attention was given, there was no difference between on-line and memory-based conditions with a group target, but there was a difference between the two with an individual target. These results imply that illusory correlation plays an important role in the performance evaluation, which could result in the biased evaluation in both individuals and groups. Other implications and limitations of the present study are discussed.