💡 How Exposure to Good Arguments Changes Your Beliefs
New research reveals that self-persuasion doesn’t require self-deception
When people present arguments in support of a particular position, their personal beliefs and attitudes tend to become more favorable toward that position. This is true even when they don’t necessarily believe in that position at the outset.
It’s important to understand why this happens since it’s relevant to how courtrooms, debates, and political events unfold. Why does the act of trying to persuade others of an argument we don’t personally hold shift our actual beliefs in the advocated direction?
The most common explanation is that it’s all an act of self-deception. We try so hard to convince other people, that we also convince ourselves in the process. The best way to make the position we’re defending seem legitimate and authentic is to strongly believe in that position ourselves and avoid any feelings of personal hypocrisy.
But a new study challenges that assumption by showing that self-persuasion is often at work even without any motivation to deceive ourselves or others.
💬 Beliefs shift with exposure, not just persuasion
In a new study published in Cognition, researchers conducted two large pre-registered experiments involving over 4,000 participants in total. The goal was to test whether self-persuasion requires self-deception or whether it’s a natural outcome of being exposed to good arguments.
In the first experiment, participants reported their beliefs and donation preferences on six polarizing societal issues (e.g. gun control, AI development, vegetarianism). Then they were randomly assigned to one of two tasks:
Persuasion condition: Participants were asked to write a persuasive message (~100 words) to convince others of a randomly assigned position.
Summary condition: Participants wrote a summary of arguments (~100 words) supporting that same side, without any persuasion goal.
After completing the task, participants re-reported their beliefs and donation preferences. This allowed researchers to measure how much people’s attitudes had shifted as a result of the exercise.
If self-deception is the key driver of self-persuasion, belief shifts should be larger in the persuasion condition, because only that group has a motive to appear convincing. But that's not what the data showed.
Instead, participants in both conditions shifted their beliefs and donation preferences significantly toward the side they had written about. There was no significant difference between the two groups. This suggests that simply thinking through arguments for one side—whether or not you’re trying to convince someone—can influence your private beliefs..
A second experiment went even further. Participants once again reported their initial beliefs and donation preferences. They were then assigned to one of two groups:
Persuasion-first group: Wrote a persuasive message about a randomly assigned position.
Summary-first group: First wrote a summary supporting the assigned position, and only afterward completed the persuasion task.
If belief change is driven by the motive to persuade, then the persuasion task should still lead to major attitude change even when it comes after the summary task. If belief change is driven merely by exposure, then doing an additional persuasion task after a summary task should have very little effect.
Consistent with the second idea, belief shifts following the persuasion exercise were five times smaller when the exercise was completed after a prior summary task rather than before the summary task. Once people had already been exposed to arguments on a topic, trying to actively persuade others had little extra influence in affecting their personal beliefs.
In completing the exercises, participants in both groups focused similarly on one-sided arguments, suggesting they put similar levels of effort into expressing the arguments in favor of a specific position. The most influential factor for self-persuasion was simply exposure to good arguments, not persuasive intent.
⭐️ Takeaway tips
#1. Arguing a side can shift your own beliefs—whether you mean to or not
If you’re asked to advocate for something—even casually—your private views may start to align with what you say, simply because you’re rehearsing arguments that support that position. Be mindful of how “taking a side” can shape your own perspective, and try to remain conscious of the best arguments for the other side.
#2. Exposure shapes belief more than motivation does
According to the study above, belief change stems from what information you attend to, not just how motivated you are to persuade others. Reading, understanding, and taking notes on arguments for a particular position are often enough. Expose yourself to good arguments from all sides so that you can be more confident in what your personal beliefs are and why you hold them.
#3. Don’t mistake belief shifts for dishonesty
When people change their views about an important issue, it’s not necessarily disingenuous or manipulative—it may just be the result of thinking more deeply about one side. Recognize that belief change can be an honest byproduct of engagement with good arguments, not a sign of bad faith, hypocrisy, dishonesty, or “flip-flopping”.
“Thaw with her gentle persuasion is more powerful than Thor with his hammer. The one melts, the other breaks into pieces.”
~ Henry David Thoreau