A large component of social perception is attribution. Attribution is the use of information gathered through observation to help individuals understand and rationalize the causes of one's own and others' behaviors. Psychological research on attribution began with the work of Fritz Heider in 1958, and was subsequently developed by others such as Harold Kelley and Bernard Weiner. People make attributions to understand the world around them in order to seek reasons for an individual's particular behavior. When people make attributions they are able to make judgments as to what was the cause or causes of a certain behavior. Attribution theory is the study of what systems and models people implement to make attributions about the behavior of others. It attempts to explain how we use information about the social environment to understand others' behavior.