Persuasive Communication
We’ve discussed a number of methods for communication up to this point. Now we turn our attention to one of the functions of communication—persuasion—and the features that might make messages more or less persuasive to an audience.
Automatic and Controlled Processing
To understand the process of persuasion, it is useful to consider two different ways we process information.27 Think about the last time you bought a can of soda. Did you carefully research brands, or did you reach for the can that had the most appealing advertising? If we’re honest, we’ll admit glitzy ads and catchy slogans have an influence on our choices as consumers. We often rely on automatic processing, a relatively superficial consideration of evidence and information, making use of heuristics like those we discussed in Chapter 6. Automatic processing takes little time and low effort, so it makes sense to use it for processing persuasive messages related to topics you don’t care much about. The disadvantage is that it lets us be easily fooled by a variety of tricks, like a cute jingle or glamorous photo.
Now consider the last time you chose a place to live. You probably sourced experts who knew something about the area, gathered information about prices, and considered the costs and benefits of renting versus buying. You were engaging in more effortful controlled processing, a detailed consideration of evidence and information, relying on facts, figures, and logic. Controlled processing requires effort and energy, and it’s harder to fool someone who has taken the time and effort to engage in it. So what makes someone engage in either shallow or deep processing? Let’s explore how we might determine what types of processing an audience will use.
Interest Level
One of the best predictors of whether people will use an automatic or controlled process for reacting to a persuasive message is their level of interest in it.28 Interest levels reflect the impact a decision is going to have on your life. When people are very interested in the outcome of a decision, they’re more likely to process information carefully. That’s probably why people look for so much more information when deciding about something important (like where to live) than something relatively unimportant (like which soda to drink).
Prior Knowledge
People who are well informed about a subject area are more likely to use controlled processing strategies. They have already thought through various arguments for or against a specific course of action, and therefore won’t readily change their position unless very good, thoughtful reasons are provided. On the other hand, people who are poorly informed about a topic can change their minds more readily, even in the face of fairly superficial arguments presented without a great deal of evidence. A better-informed audience is likely to be much harder to persuade.
Personality
Do you always read at least five reviews of a movie before deciding whether to see it? Perhaps you even research films by the same stars and director. If so, you are probably high in need for cognition, a personality trait of individuals who are most likely to be persuaded by evidence and facts.29 Those who are lower in their need for cognition are more likely to use automatic processing strategies, relying on intuition and emotion to guide their evaluation of persuasive messages.
Message Characteristics
Another factor that influences whether people use an automatic or controlled processing strategy is the characteristics of the message itself. Messages provided through relatively lean communication channels, with little opportunity for users to interact with the content of the message, encourage automatic processing. Conversely, messages provided through richer communication channels encourage more deliberative processing.
Tailoring the Message
The most important implication is to match your persuasive message to the type of processing your audience is likely to use. When the audience is not interested in a persuasive message topic, when they are poorly informed, when they are low in need for cognition, and when information is transmitted through relatively lean channels, they’ll be more likely to use automatic processing. In these cases, use messages that are more emotionally laden and associate positive images with your preferred outcome. On the other hand, when the audience is interested in a topic, when they are high in need for cognition, or when the information is transmitted through rich channels, then it is a better idea to focus on rational arguments and evidence to make your case.