Lying to others is clearly a no-no, at least theoretically. You’re aware when you’re spouting forth an untruth. Even if your motives for doing so are above reproach (Why hurt the feelings of someone in a truly ugly outfit?), there’s still a bright line between lies and truth.
What about the lies you tell yourself? Aren’t you also aware of these? After all, you know when you’ve had “one too many” of something that’s bad for you. It’s not pleasant to admit it, but the truth is definitely “out there” (or, in this case, “in here”).
An act of self-deception may seem pretty harmless, all things considered, especially when compared to lying to others. But why bother? There’s nothing really in it for you other than maybe feeling better in the moment.
The Psychology of Self-Deception
A new study by University of California, Berkeley’s Yunhao Zhang and MIT’s David Rand (2025) looks at self-deception as a variant of self-persuasion. Again, this may seem odd. Why and/or how would you want to persuade yourself of a particular position?
However, it turns out that self-persuasion occurs, and in a remarkably simple way. All you have to do is come up with an argument on one side or another in a given debate. Lo and behold, you’ll soon come to believe in that position, even if you didn’t choose it in the first place. Self-deception comes next, as you start to tell yourself that this is how you truly feel.
As Zhang and Rand point out, all of this is reminiscent of what happens when you step into the uncomfortable state of cognitive dissonance. Let’s say Larry is a sales representative whose company just released a new product onto the market. Initially, he thought the product was a waste of money, but he still had to go out and sell it. Several days after going through his pitch to potential customers, he has come to believe heartily in the product’s worth.
The self-deception wrapped up in self-persuasion occurs, according to the cognitive dissonance argument, because Larry needed to make his beliefs consistent with his behavior. Maybe he felt hypocritical about selling a worthless product.
The Path From Self-Persuasion to Self-Deception
Zhang and Rand suggest that people don’t mean to lie to themselves; they just fall victim to the effect of self-persuasion. Prior researchers, however, “model self-deception on interpersonal deception,” meaning that they see it as an intentional shift. Across two large-scale online experiments (with more than 4,000 participants), the authors tested their own theory that the mere exposure to information could be enough to set off the lies people tell themselves.
The first study presented participants with the task of rating how much they believed in six pre-determined policy statements (e.g., “Following a vegetarian diet is healthful for human beings”). Then half were randomly assigned to a persuasion condition where they were told they’d be paid to provide a compelling argument for (or against) their position. The other half of the participants were told only to write a summary of the argument, again either for or against, depending on random assignment. The findings supported the prediction that people would change their positions in both conditions after supporting the opposite view, meaning that they needed no special incentive to change sides.
In the second study, different policy statements were used, but the manipulation was changed so that participants were in both the summary and persuasion conditions. Here again, “simply being asked to summarize arguments without any persuasion goal was just as effective.”
These findings led the authors to conclude that we’ll change our beliefs not out of any particular motive to seem consistent, but just by taking the other side of an argument. We don’t need to persuade ourselves to change our minds; we’ll do it without even making a conscious effort.
How easy it is, then, to slide into a belief that goes against our own initial position. The authors liken this process to what happens when we just read aloud someone else’s (not our own) side of an argument. If we’re not careful, we’ll start believing not just what other people say, but what we say, even if we didn’t really mean it in the first place.
How to Avoid the Backsliding Lie
Clearly, backsliding into what for you is an untruth is a process that you need to guard yourself against. It’s possible, as the authors argue, that you enter the backslide because once you start to articulate the opposite position, you see previously hidden nuances. Maybe, after all, you force yourself to admit to some downsides to vegetarian diets once you have to come up with them. Perhaps, like Larry, you’ll see there are some benefits to that product he’s telling people about. On the other hand, these mental gymnastics could lead you away from an honest position that it’s taken you years to hone.
Deception Essential Reads
To sum up, there’s a lesson in all of this to not let “simple exposure,” or lack of effort, keep you from holding onto positions that have helped to define who you are as a person. It’s all too easy to lie to yourself, even with no incentive to do so. Take the time to consider your own honest views, and you’ll be able to find the fulfillment of following your own moral pathway.
