Working knowledge, cognitive processing, and attitudes: On the determinants of bias

This experiment demonstrated that attitude-relevant knowledge can enable biased or objective systematic processing of new information. Subjects having a high or low knowledge on AIDS risk prevention evaluated a series of scenarios estimating the likelihood of contracting AIDS from sexual behavior. Knowledgeable subjects who reported considerable fear of AIDS engaged in biased processing of the risk estimates. The intense affect apparently motivated these subjects to use their knowledge to bolster and defend their existing attitudes toward AIDS risk: They gave more favorable evaluations of risk estimates that supported their attitudes than estimates that opposed them. In contrast, knowledgeable subjects who reported only moderate AIDS fear did not appear motivated to assume a defensive stance and instead processed the AIDS risk estimates in a critical objective manner regardless of the congruence with their own attitudes. Less knowledgeable subjects did not demonstrate either a biased or an objectively critical processing orientation.