Contrast effects in judgments of health hazards.

Researchers commonly use 2 models to explain contrast effects (CEs): the standard-of-comparison model and the set-reset model. The 2 models focus on the role of categorization to predict when a CE (instead of an assimilation effect) will happen, while minimizing the role of knowledge accessibility and relevance in determining whether any effect will occur. A 3rd model, the selective-accessibility model (F. Strack & T. Mussweiler, 1997), focuses on knowledge accessibility and relevance, but it is a model of assimilation effects in the anchoring bias. In the present study of CEs, the authors tested 3 predictions implied by the selective-accessibility model. The authors found a CE only when anchor- and target-rating dimensions matched and only in the 1st of multiple targets rated. The CE required a minimum amount of attention to the anchor. These results support the account that selective knowledge accessibility and relevance play an important role in CEs.