People use emotion to persuade, even when it could backfire

"Beyond simply becoming more positive or negative, people spontaneously shift toward using more emotional language when trying to persuade," says researcher Matthew D. Rocklage of The Kellogg School of Management at Northwestern University.

We might imagine that people would use very positive words such as "excellent" or "outstanding" to bring others around to their point of view, but the findings showed that people specifically used terms that convey a greater degree of emotion, such as "exciting" and "thrilling."

Understanding the components that make for a persuasive message is a critical focus of fields ranging from advertising to politics and even public health. Rocklage and colleagues wanted to look at the question from a different angle, exploring how we communicate with others when we are the ones trying to persuade.

"It's possible that to be seen as rational and reasonable, people might remove emotion from their language when attempting to persuade," says Rocklage. Drawing from attitudes theory and social-function theories of emotion, however, Rocklage and colleagues Derek D. Rucker and Loran F. Nordgren hypothesized that people would go the other way, tapping into emotional language as a means of social influence.

In one online study, the researchers showed 1,285 participants a photo and some relevant details for a particular product available from Amazon . com. They asked some participants to write a five-star review that would persuade readers to purchase that product, while they asked others to write a five-star review that simply described the product's positive features.

Using an established tool for quantitative linguistic analysis, the Evaluative Lexicon, the researchers then quantified how emotional, positive or negative, and extreme the reviews were.

Although the reviews were equally positive in their language, the data showed that reviewers used more emotional language when they were trying to persuade readers to buy a product compared with when they were writing a five-star review without intending to persuade. Participants' persuasive reviews also had more emotional language compared with actual five-star reviews for the same products published on Amazon . com.

Importantly, the shift toward more emotional language appeared to be automatic rather than deliberative. Participants still used more emotional descriptors in persuasive reviews when they were simultaneously trying to remember an 8-digit number, a competing task that made strategizing very difficult.

The tendency to use more emotional language emerged even when participants were attempting to persuade a group of "rational" thinkers.

"Past research indicates that emotional appeals can backfire when an audience prefers unemotional appeals," says Rocklage. "Our findings indicate that there is a strong enough connection between persuasion and emotion in people's minds that they continue to use emotion even in the face of an audience where that approach can backfire."

Indeed, additional evidence indicated a connection between emotion and persuasion in memory. The researchers found that the more emotional a word was, the more likely participants were to associate it with persuasion and the quicker they did so.

An interesting avenue for future research, says Rocklage, is to investigate whether the association transfers across various contexts.

"For instance, would people use less emotion if they were in a boardroom meeting or if they were writing a formal letter of recommendation?" he wonders.