Another objective of this research was to examine people's readiness to form a particular kind of illusory correlation: one between people diagnosed with a mental health condition and undesirable behaviors (especially violent behaviors).
The current research utilized the traditional illusory correlation experimental paradigm introduced by Hamilton and Gifford (1976).
The hypotheses were that (1) the illusory correlation effect would be replicated, that (2) the effect would be most pronounced for participants of moderate AC (relative to those with high or low levels), and that (3) the effect would also be most pronounced when the group characterized as "diagnosed with a mental illness" appeared in the minority and the behavioral statements included violent behaviors.
Although a formal power analysis was not conducted, the number of participants in the study met or exceeded the number in previous published experiments testing for the effect of a moderating variable (in this case, AC) on illusory correlation formation (e.g., Pryor, 1986; Sanbonmatsu, Shavitt, & Sherman, 1991; Stroessner et al., 1992).
Thus, in terms of the memory data, the illusory correlation effect was replicated: relative to positive behaviors, participants overattributed negative behaviors to the minority group.
Distinctiveness-based illusory correlations
and stereotyping: A meta-analytic integration.
However, a number of studies have identified factors that can weaken the distinctiveness-based illusory correlation effect (Schaller & Maass, 1989; Spears, van der Pligt & Eiser, 1985), or have shown that illusory correlation effects can occur without statistical infrequency of a particular category (Berndsen, Spears & van der Pligt, 1996a; Spears, van der Pligt & Eiser, 1986).
According to Smith (1991) and Fiedler (1991; see also Fiedler, Russer & Gramm, 1993), the illusory correlation phenomenon is a result of memory biases.
In contrast to these explanations based on biased information processing, McGarty, Haslam, Turner & Oakes (1993) proposed that illusory correlation resulted from attempts to differentiate meaningfully between stimulus groups.
In order to accentuate differences between group A and B in the illusory correlation task, participants need to perceive some contrast or difference between the two groups (i.e.
as an obstacle to the use of valid psychodiagnostic signs.
While what they do might well be valid, how they say it when consciously reconstructing it often takes the form of illusory correlations
, errors of cause-effect interpretations, or generalization beyond the bounds of their experience.