The elaboration likelihood model (ELM) of persuasion is a dual process theory describing the change of attitudes form. The ELM was developed by Richard E. Petty and John Cacioppo in the mid-1980s. The model aims to explain different ways of processing stimuli, why they are used, and their outcomes on attitude change. The ELM proposes two major routes to persuasion: the central route and the peripheral route. Under the central route, persuasion will likely result from a person's careful and thoughtful consideration of the true merits of the information presented in support of an advocacy. The central route involves a high level of message elaboration in which a great amount of cognition about the arguments are generated by the individual receiving the message. The results of attitude change will be relatively enduring, resistant, and predictive of behavior. On the other hand, under the peripheral route, persuasion results from a person's association with positive or negative cues in the stimulus or making a simple inference about the merits of the advocated position. The cues received by the individual under the peripheral route are generally unrelated to the logical quality of the stimulus. These cues will involve factors such as the credibility or attractiveness of the sources of the message, or the production quality of the message. The likelihood of elaboration will be determined by an individual's motivation and ability to evaluate the argument being presented.