In psychology, the negativity effect is the tendency of people, when evaluating the causes of the behaviors of a person they dislike, to attribute positive behaviors to the situations surrounding the behaviors and negative behaviors to the person's inherent disposition. 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 attribution biases. The negativity effect plays a role in producing the fundamental attribution error, a major contributor to prejudice.
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, however, display less of this tendency and more of the opposite tendency (the positivity effect).