This post is by Carme Isern-Mas and Ivar R. Hannikainen whose paper, "Self-Deception: A Case Study in Folk Conceptual Structure", was recently published open access in Review of Philosophy and Psychology.
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| Carme and Ivar |
In the first episode of Crazy Ex-Girlfriend, successful New York lawyer Rebecca Bloom bumps into her ex-boyfriend Josh Chan, who announces he is moving back to his hometown in California. Impulsively, Rebecca quits her job and follows him. Although she claims this is simply to live near the beach, it is clear to the audience that she is really hoping to win Josh back.
Does Rebecca’s case count as self-deception? As with many other concepts in analytic philosophy, this hinges on how different features or conditions shape the concept of self-deception. Intentionalists argue that self-deception requires the agent to intend to deceive themselves, often starting from an unwelcome true belief. On this view, Rebecca must knowingly suppress her true motive and deliberately convince herself she is moving for the beach.
Motivationalists, by contrast, deny that intention or prior belief are necessary. For them, self-deception arises through motivationally biased reasoning, where a desire (e.g., for Josh) shapes belief formation unconsciously. Both views also debate whether self-deception must succeed, meaning the person ends up genuinely believing the falsehood.
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| Poster of Crazy Ex Girlfriend |
Our paper approached these questions empirically. Study 1 tested whether laypeople endorse the intentionalist view. Participants read vignettes where we manipulated three factors: (1) whether the agent intended to self-deceive, (2) whether they held an antecedent belief, and (3) whether they succeeded in forming the false belief.
Study 2 examined the motivationalist view. Participants evaluated cases where belief formation resulted from (1) motivated reasoning, unmotivated bias, or error; and (2) where the outcome was either successful or not. All the manipulated factors influenced judgments of self-deception, suggesting that people treat intent, motive, and belief change as sufficient, but non-necessary, for self-deception.
Our participants acted neither as intentionalists nor as motivationalistsm, but as a mixture of both. This raised a deeper question: Do people disagree about what self-deception is (the “disagreement view”), or are they themselves conflicted (the “conflict view”)? Study 3 used a within-subjects design and by-participant regression models to analyze how individuals weighed different features.
We asked each participant their self-deceptions ratings for a lot of cases and then built models that predicted the behavior of each participant individually (see the figure below for examples of such models). The analysis of these models allowed us to see that intrapersonal conflict, rather than inter-personal disagreement, best explained opposing intuitions. In other words, many individuals experienced internal conflict instead of simply disagreeing with others.
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| Observed and Predicted Probabilities of Self-Deception Judgment by Case |
Besides, most participants gave partial weight to multiple features, rather than rigidly following a classical model of self-deception. Only a minority saw one feature, or a combination of features, as necessary and sufficient. This suggests that the folk concept of self-deception has a prototype structure: people judge cases based on similarity to a typical example, not strict definitions.
Philosophically, this matters. It suggests that conceptual analysis might struggle with everyday concepts that are prototype-based rather than definition-based. Moreover, the lack of a consensual folk view on most philosophical questions might not be due to clashing views between individuals, but to internal tension within each of us. The case of ‘self-deception’ illustrates a disconnect between rigid, expert theories and flexible, everyday concepts.