Why Persuasion Is Personal: The Neuroscience of Influence

What’s going on in a person’s head when a set of arguments actually changes their opinion? Is it the rational analysis of evidence? Is it a simple emotional reaction? In truth, it could be either of those things. But at the end of the day, the key is that persuasion is personal.

What I mean is that compelling persuasive messages tend to be the ones that get people to connect the ideas to something about themselves.

Early research showed the power of “self-relevant” thoughts by asking people to write down the thoughts that came to their mind as they read a persuasive message. The researchers could then look over the thoughts that people listed to see whether there were themes. The evidence tended to show that when people’s responses to a message were more connected to themselves, the message was more successful at changing opinions.

Seeing the Self in the Brain

More recently, persuasion scientists have turned to state-of-the-art methods of peering into people’s brains as they read messages or watch advertisements. These tools give us a glimpse into how our brains react to a message that ultimately changes our minds.

To test the idea that persuasion is personal, you could look to one part of the brain in particular: the ventromedial prefrontal cortex or vMPFC for short. Researchers have tended to find that this part of the brain gets used when people are thinking about themselves. In fact, it’s also a part of the brain that’s involved in the process of evaluating the world around us, so it would make sense for this brain region to be important for persuasion.

Research by Dr. Emily Falk and her colleagues has continued to find that the vMPFC is involved in the persuasion process. For example, in one study, they measured the brain activity of a bunch of smokers. While these participants were in a brain scanner, they saw a series of animated advertisements encouraging people to quit smoking. These were real ads from the organization, “BecomeAnEx.” More than a month later, the researchers followed up with everyone to see how much they were still smoking cigarettes.

When they looked at how much people had cut their smoking habits, they found that the more the self-reflection area of their brains were active as they watched the advertisements, the fewer cigarettes they ended up smoking. In other words, it was when an ad captivated a person’s self-reflective thinking that it was most persuasive.

Enhancing a Message’s Persuasive Power

So it’s clear that messages tend to have more impact when they tickle our self-centered thinking. But do some messages do that better than others?

Yes. We’ve known for a long time that when communicators tailor their messages to the unique values of their audience, they can have more influence. And new evidence suggests that this is because these tailored messages activate the same self-focused brain areas that we know enhance persuasion.

Researchers compared people’s reactions to two types of advertisements for a product. The first type of ad was emotionally evocative, highlighting the joy you’d feel from using the product. The other type of ad relied on making rational arguments, focusing on what makes the product especially useful.

They also gave the same people a questionnaire, which assessed how much they were the type of person who cares a lot about their emotional experiences versus whether they care more about thinking carefully about information.

Consistent with other research in persuasion, more emotion-focused people are more persuaded by emotionally evocative ads and more rationality-focused people are more persuaded by rational ads. That may not be that surprising, but the new study gives us a glimpse into why these patterns of results occur. They found that the same self-focused brain area (the vMPFC) was most active when people were seeing an advertisement in whichever style matched their personal emotional-rational preferences.

Persuasion Is Personal

From classic research in persuasion to new evidence with brain scanning technology, the data we have shows that messages are more persuasive when they get people connecting the ideas to some aspect of themselves. This is what I mean when I say “persuasion is personal.”

Communicators may want to take note of this finding. Just because something seems important or persuasive to you doesn’t mean it’ll be compelling to your audience. Think about how to speak to your audience’s selfish motives and keep their unique values and personalities in mind in order to maximize influence.