Elaboration likelihood model: would attractiveness be a peripheral or central route? In the elaboration likelihood model, if an advertisement contains an attractive person, would this be using the central route or peripheral route? I would guess it would be peripheral route, since people don't tend to think about if a person is attractive or not, but on the other hand, if the person does think about the person's appearance and finds them attractive, then it could be considered central.
Unless the advertisement is actually advertising the person's attractiveness directly, this should be a peripheral issue. Consider Wikipedia's description of the central route:


  Central-route processes involve scrutiny of persuasive communication (e.g., a speech or an advertisement) to determine the arguments' merits. Under these conditions, a person's cognitive response to the message determines its persuasive outcome. If they evaluate a message as reliable, well-constructed and convincing, it may be received favorably even if it contrasts with the receiver’s original position on the message.


Thus the only circumstance in which a person's attractiveness should be a central route is one in which the advertisement's argument is about the person's attractiveness per se...I'm not sure I can even think of a good example of such an advertisement. Even beauty product advertisements (which are about the product, not the person) routinely appeal through peripheral routes by using supermodels with immaculately styled hair, wearing much more makeup than the object of the advertisement – not to mention expensive clothes and other fashion accessories – in idealized, studio-lighted environments. If anything, factors like these obscure the real efficacy of the given beauty product, because most observers will just be overwhelmed by the model's beauty and by the desire to emulate it, regardless of how little the product in question has to do with it. Again, see Wikipedia on the peripheral route:


  Peripheral-route processes do not involve elaboration of the message through cognitive processing of an argument's merits. They rely on a message's environmental characteristics: the perceived credibility of the source, message presentation quality, the source's attractiveness or a catchy slogan, and is frequently used when the argument is weak or lacks evidence. The peripheral route is a mental shortcut which accepts (or rejects) a message based on external cues, rather than thought. It is used when the audience is unable to process the message due to the message's complexity or the audience's immaturity. The commonest influences are rewards such as food, sex or money, which create rapid changes in mind and action. Celebrity status, likability, humor and expertise are other factors governing the peripheral process. Appearance can gain an individual's attention; while it can create interest in a topic, it will not effect strong change. The goal of the peripheral process is to create change which can be weak (or temporary) compared with the strong, lasting change of the central route.