The claim states that physical attractiveness acts as a peripheral route in the elaboration likelihood model (ELM). In communication and persuasion theory, source attractiveness is the quintessential textbook example of a peripheral cue (alongside source credibility, expert status, or pleasant background music) that influences attitudes via the peripheral route when elaboration likelihood is low. While empirical studies examine boundary conditions, the categorization of source attractiveness as a peripheral cue is a definitional and foundational tenet of the Elaboration Likelihood Model introduced by Petty and Cacioppo. Therefore, it is treated as common knowledge within the field and does not require specific citation to validate its premise.