APA Dictionary of Psychology

a personality trait reflecting a person’s tendency to engage in extensive evaluative thinking when encountering people, issues, or objects. People who are high in need to evaluate tend to form attitudes and categorize objects spontaneously along a positive–negative scale. People who are low in need to evaluate tend to think of objects in evaluative terms only when the context encourages such categorization. [originally investigated by U.S. psychologists William Blair Gage Jarvis and Richard E. Petty (1951–  )]