Negativity effect refers to the greater weight given to negative information relative to equally extreme and equally likely positive information in a variety of information-processing tasks. In psychology, the negativity effect is the tendency of people, when evaluating the causes of the behaviors of a person they dislike, to attribute their positive behaviors to the environment and their negative behaviors to the person's inherent nature. The negativity effect is the inverse of the positivity effect, which is found when people evaluate the causes of the behaviors of a person they like. Both effects are attributional biases. The negativity effect plays a role in producing the fundamental attribution error, a major contributor to prejudice.[according to whom?]
The term negativity effect also refers to the tendency of some people to assign more weight to negative information in descriptions of others. Research has shown that the negativity effect in this sense is quite common, especially with younger people; older adults[quantify], however, display less of this tendency and more of the opposite tendency (the positivity effect).