Social Science and Persuasion

Learning Objectives

  1. Understand findings from experiments using the Yale Attitude Change Approach
  2. Use the principles of ELM to more effectively design persuasive communications

Aristotle’s three rhetorical appeals—ethos, logos, and pathos—have been employed as persuasive strategies for two thousand years even though there was no proof they were effective. It wasn’t until the 1940s that Psychologists began studying persuasion from a scientific perspective using social experiments and evidence to produce new theories.  Although based in social science, such persuasive strategies are regularly employed and researched in communication due to their role in advertising, marketing, politics, and other industries.

Much of the persuasion we experience comes from outside forces. How do people convince others to change their attitudes, beliefs, and behaviors? What communications do you receive that attempt to persuade you to change your attitudes, beliefs, and behaviors? A subfield of social psychology studies persuasion and social influence, providing us with a plethora of information on how humans can be persuaded by others.

Yale Attitude Change Approach

The topic of persuasion has been one of the most extensively researched areas in social psychology (Fiske et al., 2010). During the Second World War, Carl Hovland extensively researched persuasion for the U.S. Army. After the war, Hovland continued his exploration of persuasion at Yale University. Out of this work came a model called the Yale attitude change approach, which describes the conditions under which people tend to change their attitudes. Hovland demonstrated that certain features of the source of a persuasive message, the content of the message, and the characteristics of the audience will influence the persuasiveness of a message (Hovland, Janis, & Kelley, 1953). In other words, who (i.e. source) says what (i.e. content) to whom (i.e. audience)?

Features of the source of the persuasive message include the credibility of the speaker (Hovland & Weiss, 1951) and the physical attractiveness of the speaker (Eagly & Chaiken, 1975; Petty, Wegener, & Fabrigar, 1997). Thus, speakers who are credible, or have expertise on the topic, and who are deemed as trustworthy are more persuasive than less credible speakers. Similarly, more attractive speakers are more persuasive than less attractive speakers. The use of famous actors and athletes to advertise products on television and in print relies on this principle. The immediate and long term impact of the persuasion also depends, however, on the credibility of the messenger (Kumkale & Albarracín, 2004).

Features of the message itself that affect persuasion include subtlety (the quality of being important, but not obvious) (Petty & Cacioppo, 1986; Walster & Festinger, 1962); sidedness (that is, having more than one side) (Crowley & Hoyer, 1994; Igou & Bless, 2003; Lumsdaine & Janis, 1953); timing (Haugtvedt & Wegener, 1994; Miller & Campbell, 1959), and whether both sides are presented. Messages that are more subtle are more persuasive than direct messages. Arguments that occur first, such as in a debate, are more influential if messages are given back-to-back. However, if there is a delay after the first message, and before the audience needs to make a decision, the last message presented will tend to be more persuasive (Miller & Campbell, 1959).

Features of the audience that affect persuasion are attention (Albarracín & Wyer, 2001; Festinger & Maccoby, 1964), intelligence, self-esteem (Rhodes & Wood, 1992), and age (Krosnick & Alwin, 1989). In order to be persuaded, audience members must be paying attention. People with lower intelligence are more easily persuaded than people with higher intelligence; whereas people with moderate self-esteem are more easily persuaded than people with higher or lower self-esteem (Rhodes & Wood, 1992). Finally, younger adults aged 18–25 are more persuadable than older adults.

Elaboration Likelihood Model (ELM)

By the 1980’s it had become apparent that simply being presented with information didn’t necessarily mean people would absorb it and be persuaded. Yet, sometimes it does work with certain messages and certain audiences? How could this be explained? This model helps us to understand how our brains process information when we are being persuaded. It shows how a person’s motivation and their ability to process information work together to determine their likelihood of being persuaded.

Elaboration” in this context refers to the effort your brain undertakes to understand, process, and evaluate information. Once we understand how this works, we can use the model to plan persuasive communications targeted to each brain process thereby increasing the likelihood that we can persuade them.

You have two “readings” for ELM:

  1. Read this article to understand the basics of the ELM model and to see how we can apply ELM to persuade a customer to complete an online purchase:
  2. After reading the article, watch this video applying ELM to advertising.




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