Negative information weighs more heavily on the brain: The negativity bias in evaluative categorizations.

Negative information tends to influence evaluations more strongly than comparably extreme positive information. To test whether this negativity bias operates at the evaluative categorization stage, the authors recorded event-related brain potentials (ERPs), which are more sensitive to the evaluative categorization than the response output stage, as participants viewed positive, negative, and neutral pictures. Results revealed larger amplitude late positive brain potentials during the evaluative categorization of (a) positive and negative stimuli as compared with neutral stimuli and (b) negative as compared with positive stimuli, even though both were equally probable, evaluatively extreme, and arousing. These results provide support for the hypothesis that the negativity bias in affective processing occurs as early as the initial categorization into valence classes. A growing catalog of errors, biases, and asymmetries points to the conclusion that negative information more strongly influences people's evaluations than comparably extreme positive information (Kanouse & Hansen, 1971; Peeters & Czapinski, 1990; Skowronski & Carlston, 1989). Impression formation is one area in which this is especially evident. In an illustrative study, Anderson (1965) found that evaluations of people described by multiple positive traits of differing extremity followed an averaging rule. The evaluation of such a person was similar to the average of the evaluations that had been given to people possessing each of the positive traits in isolation. By contrast, the evaluation of a person described by multiple negative traits of differing extremity was less favorable than expected from an averaging model. This suggests that negative traits are given greater weight in overall evaluations than are positive traits (see also Birnbaum, 1972; Feldman, 1966; Fiske, 1980; Hodges, 1974). A greater weighting for negative information than positive information can also be seen in risk-taking research, where the axiom that losses loom larger than gains often holds. The distress that people report in association with the loss of a given quantity of money typically exceeds the amount of pleasure associated with gain of that same amount (e.g., Kahneman & Tversky, 1984). More generally, Taylor (1991) has noted a tendency for negative events to result in a greater