The person–situation debate in personality psychology refers to the controversy concerning whether the person or the situation is more influential in determining a person's behavior. Personality trait psychologists believe that people have consistent personalities that guide their behaviors across situations. Situationists, opponents of the trait approach, argue that people are not consistent enough from situation to situation to be characterized by broad personality traits. The person–situation debate in personality psychology refers to the controversy concerning whether the person or the situation is more influential in determining a person's behavior. Personality trait psychologists believe that people have consistent personalities that guide their behaviors across situations. Situationists, opponents of the trait approach, argue that people are not consistent enough from situation to situation to be characterized by broad personality traits. Interest in determining whether there were any generalities in behavior began in the 1920s and 30s. Gordon Allport and Henry Murray both supported the idea of a consistent personality with occasional situational influences. Allport noted that 'traits become predictable to the extent that identities in stimulus situations are predictable.' Others like Edward Thorndike viewed behavior as a composition of responses an individual has to situations. In 1968, Walter Mischel published a book called Personality and Assessment claiming that behavior is too cross-situationally inconsistent to be classified with personality traits. He stated: '...with the possible exception of intelligence, highly generalised behavioral consistencies have not been demonstrated, and the concept of personality traits as broad dispositions is thus untenable':146 His book was a non-systematic meta-analysis of some of the research on the relationship between behavioral and personality traits (assessed by either self-report or peer-report). The book also assessed studies regarding measurements of behavior from one situation to another. This book generated a formidable dispute between social psychologists and trait theorists because trait questionnaires had been used to measure personality for many decades. Behaviorism had dominated the field of psychology up until this time, making Mischel's claim devastating to the mainstream consensus amongst personality psychologists and causing many psychologists to question and doubt whether personality exists. According to David C. Funder, Mischel's book posed three main questions: More recently, Mischel has retracted some of his original claims, protesting that some psychologists misinterpreted his argument to mean he believes personality does not exist. Situationists had a number of arguments, but they can be generally summarized into four: Because of the aforementioned points, situationists argued that the predictive ability of personality traits is severely lacking. Opponents of the trait approach claimed that the idea of personality traits is fundamentally flawed and that behavior would be better understood through conditioning and learning processes.