The psychology of persuasion, often associated with fields such as politics and the advertising industry, has been a long-time topic of interest for researchers. Now, a new study has explored how far people displayed linguistic choices that seemed to associate emotion and persuasion. The paper titled 'Persuasion, Emotion, and Language: The Intent to Persuade Transforms Language via Emotionality' was published in the journal Psychological Science on 15 March 2018.

When attempting to persuade, the study found that people didn't just use words that described something in a positive (or negative) way, such as "excellent" or "outstanding". People were inclined to use words that conveyed emotional impact such as "exciting" and "thrilling."

"Beyond simply becoming more positive or negative, people spontaneously shift toward using more emotional language when trying to persuade," explains researcher Matthew D. Rocklage of The Kellogg School of Management at Northwestern University. While many try to understand what constitutes a persuasive message, Rocklage and his colleagues took a reversed approach to understand how people communicate when they have to persuade others.

1,285 participants were provided with a picture and details about a particular product from an online shopping website. Some participants were asked to write a five-star review that would persuade readers to purchase that product, while other participants were asked to write a five-star review that simply described the product's positive features. 

The researchers used the Evaluative Lexicon, an established tool for quantitative linguistic analysis that allowed them to measure how emotional, positive or negative, and extreme the reviews were. While it was revealed that all the reviews were equally positive in their language, the analysis showed that people used more emotional language when trying to persuade readers to buy the product.

"This work revealed that the intent to persuade other people spontaneously increases the emotionality of individuals’ appeals via the words they use," the authors write. In other words, this shift appeared to be automatic rather than a conscious, deliberative decision. The tendency to use emotion remained even when participants were persuading 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."

In addition, "an association in memory between persuasion and emotionality" was also found through direct evidence. The more emotional a word was, the more likely participants were to associate it with persuasion and the quicker they did so.

Rocklage suggests that future research should consider investigating how far this style of persuasion is used in various other 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 asks.