 Researcher Robert Baron (2005) contends that the connection between certain antecedents which Janis believed necessary has not been demonstrated by the current collective body of research on groupthink.He believes that Janis' antecedents for groupthink are incorrect, and argues that not only are they "not necessary to provoke the symptoms of groupthink, but that they often will not even amplify such symptoms".As an alternative to Janis' model, Baron proposed a ubiquity model of groupthink.