What do people mean when speaking of evilness?

The term evilness started to become popular in social psychology after the publication in 1999 of the special issue edited by Arthur G. Miller, "Perspectives on evil and violence". It is usually used to define behaviors that are extremely and strongly harmful. However, the concept is still imprecise and needs to be empirically delineated. This article attempts to answer the following questions. What is evilness? What is the difference between aggression and evilness? We conducted several studies with three goals: to analyze how laypersons and experts define evilness, to verify whether laypeople distinguish between different intensities of evilness, and to determine the dimensions that predict aggression and evilness. The results offer preliminary answers to the three questions.