Kirsten I. Ruys

This article has been retracted.

The following articles have been retracted from publication in Psychological Science:

What are the necessary preconditions to make people feel good or bad? In this research, the authors aimed to uncover the bare essentials of mood induction. Several induction techniques exist, and most of these techniques demand a relatively high amount of cognitive capacity. Moreover, to be effective, most techniques require conscious awareness. The authors proposed that the common and defining element in all effective mood induction techniques is the dominating salience of evaluative tone over descriptive meaning. This evaluative-tone hypothesis was tested in two paradigms in which the evaluative meaning of the "primed" concept was more salient than its descriptive meaning (i.e., when subliminal stimulus exposure was so short that mainly the evaluative meaning was activated [see D. A. Stapel, W. Koomen, & K. I. Ruys, 2002] and when the primed concepts were sufficiently extreme such that evaluative meaning always dominated descriptive meaning). Explicit and implicit mood measures showed that the activation of a dominating evaluative tone affected people's mood states. Implications of these findings for theories on unconscious mood induction are discussed.

The following articles have been retracted from publication in Psychological Science:

Numerous studies have shown that social categorization is a flexible process that partly depends on contextual variables. However, little is known about the role of affect in people's access to categorical dimensions. We investigated the hypothesis that social category activation is facilitated on evaluatively congruent dimensions. Two studies provide support for this evaluative-matching hypothesis, in which social categorization was found to be faster and more accurate for evaluatively congruent categories (i.e., unattractive foreigners, unattractive prostitutes, attractive fellow-citizens and attractive brides) than for evaluatively incongruent categories (i.e., attractive foreigners, attractive prostitutes, unattractive fellow-citizens and unattractive brides). We discuss the theoretical and practical implications of these findings.

Whether two people are presented as similar or different may have a strong impact on the outcome of their comparison. In the present research, we examined the counterintuitive hypothesis that activating dissimilarity increases the perception of similarities between people, in other words increases perceived feature overlap, during the comparison process. We investigated this prediction by asking people to judge the perceived similarity between two faces with a suboptimally related or unrelated morph inserted in between (to influence joint categorization), and with similar or different facial expressions (to vary the salience of similar or different features). The results confirmed our expectations: In the similarity (joint categorization) condition, two faces that differed in expression were perceived as more dissimilar than faces with the same expression. More important for our prediction, in the dissimilarity condition two faces with different expressions were no longer perceived as more dissimilar than two faces with the same expression. We discuss implications of these findings for the mechanisms underlying comparisons between people. Copyright © 2007 John Wiley & Sons, Ltd.