Elaboration likelihood model

The elaboration likelihood model (ELM) of persuasion is a model of how attitudes are formed and changed that was developed by R. E. Petty and J. T. Cacioppo in the early 1980s (see also attitude change). Central to this model is the "elaboration continuum", which ranges from low elaboration (low thought) to high elaboration (high thought). The ELM distinguishes between two routes to persuasion: the "central route," where a subject considers an idea logically, and the "peripheral route," in which the audience uses preexisting ideas and superficial qualities to be persuaded

Central route

Central route processes are those that require a great deal of thought, and therefore are likely to predominate under conditions that promote high elaboration. Central route processes involve careful scrutiny of a persuasive communication (e.g., a speech, an advertisement, etc.) to determine the merits of the arguments. Under these conditions, a person's unique cognitive responses to the message determine the persuasive outcome (i.e., the direction and magnitude of attitude change). So, if favorable thoughts are a result of the elaboration process, the message will most likely be accepted (i.e., an attitude congruent with the message's position will emerge), and if unfavorable thoughts are generated while considering the merits of presented arguments, the message will most likely be rejected. In order for the message to be centrally processed, a person must have the ability and motivation to do so.

Peripheral route

Peripheral route processes, on the other hand, do not involve elaboration of the message through extensive cognitive processing of the merits of the actual argument presented. These processes often rely on environmental characteristics of the message, like the perceived credibility of the source, quality of the way in which it is presented, the attractiveness of the source, or the catchy slogan that contains the message.


  

Choice of route

The two factors that most influence which route an individual will take in a persuasive situation are motivation (strong desire to process the message; e.g., Petty & Cacioppo, 1979) and ability (actually being capable of critical evaluation; e.g., Petty, Wells, & Brock, 1976). Which route is taken is determined by the extent of elaboration. Both motivational and ability factors determine elaboration. Motivational factors include (among others) the personal relevance of the message topic, accountability, and a person's "need for cognition" (their innate desire to enjoy thinking). Ability factors include the availability of cognitive resources (e.g., the presence or absence of time pressures or distractions) or relevant knowledge needed to carefully scrutinize the arguments. The subject's general education level, as well as their education and experience with the topic at hand greatly affect their ability to be persuaded. Under conditions of moderate elaboration, a mixture of central and peripheral route processes will guide information processing

 Testing the Elaboration Likelihood Model

To design a way to test the Elaboration Likelihood Model, it is crucial to determine whether an argument is universally seen as strong or weak. If an argument is inconsistent in opinions of strength, the results of persuasion will be inconsistent. In general, a weak argument that is universally viewed as weak will entice unfavorable results if the subject is instructed to and is in an appropriate environment to consider it logically (or when testing the central route of the Elaboration Likelihood Model). In turn, a strong argument under similar circumstances will return favorable results. The test arguments must also be rated for ease of understanding, complexity, and familiarity. To scientifically study either route of the Elaboration Likelihood Model, the arguments themselves must be designed to have consistent results.
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