Appendix 8: psychology of bias.

Psychological Evaluations of Negativity Bias: psychologists have discovered that there is a tendency for humans to give greater weight to negative events than positive events. This should be considered when public officials are trying to communicate strategies for protecting against attacks or coping with the outcomes of attacks.

Rozin, Paul; Royzman, Edward B. Negativity bias, negativity dominance, and contagion (2001). Personality & Social Psychology Review. Vol. 5(4), 296-320.

These investigators found that there is a general bias, based on both innate predispositions and experience, in animals and humans, to give greater weight to negative events or attributes. This is evident in four ways: (a) negative potency (negative entities are stronger than the equivalent positive entities), (b) steeper negative gradients (the negativity of negative events grows more rapidly with approach to them in space or time than does the positivity of positive events), (c) negativity dominance (combinations of negative and positive entities yield evaluations that are more negative than the algebraic sum of individual subjective evaluations would predict), and (d) negative differentiation (negative entities are more varied, yield more complex conceptual representations, and engage a wider response repertoire). The authors review this taxonomy, with emphasis on negativity dominance, including literary, historical, religious, and cultural sources, as well as the psychological literatures on ...