WHETHER RECOMMENDING A RESTAURANT, endorsing a brand or promoting a policy, it seems reasonable to think that the more arguments you can provide, the more persuaded your audience will be. Indeed, past research suggests that, assuming one has compelling points, providing many rather than few arguments generally promotes greater persuasion.
Laypeople share this belief. When I asked 249 online participants whether giving a low or high number of arguments would be more persuasive, 59 per cent indicated that using a high number of arguments would be the better strategy.
In contrast to this view, in recent research with Mohamed Hussein and Zakary Tormala of Stanford University’s Graduate School of Business, we posited that a high rather than low number of arguments might have conflicting effects on persuasion. And further, these competing effects might actually cancel each other out, resulting in minimal or no overall benefit to persuasion from using more arguments. In this article I will summarize our research and the key takeaways.
Less Can Be More
Past research suggests that the more arguments one provides for a position, the more persuasive one tends to be. In one notable study, participants were asked to imagine being trial jurors and read arguments for both the prosecution and the defence. Then, they rated how guilty the defendant was. The researchers varied the number of arguments given by the prosecution and the defence to be one, four or seven. Results indicated that the more arguments provided by the prosecution, the more guilty participants found the defendant to be — and the same went for the defence. In other words, more arguments led to more persuasion.
As predicted, there was both
