I found this meta-analysis via Dan Willingham. While true experts are less likely to overclaim knowledge they do not have, self-perceived experts are more likely to overclaim knowledge they do not have. The study also concludes that expertise protects against overclaiming more when self-perceived expertise is high. And yes, this meta-analysis made me think Dunning-Kruger effect too.

The meta-analysis conducted across 17 studies, aimed to explore if genuine expertise reduces this tendency and if it interacts with self-perceived expertise, which often leads individuals to overestimate their knowledge.

The study begins by examining the notion that overclaiming is a metacognitive error, where individuals mistakenly believe they are familiar with non-existent items due to their reliance on heuristics or cognitive shortcuts. The authors differentiate between genuine expertise, which reflects actual knowledge, and self-perceived expertise, the subjective sense of being knowledgeable. Prior research suggests that self-perceived experts are more prone to overclaiming. In contrast, genuine experts should, theoretically, have better “meta-knowledge” and be more accurate in recognizing what they do not know.

Key findings from the meta-analysis reveal that genuine expertise provides some protection against overclaiming, though the effect is modest. Experts are generally less likely to claim familiarity with non-existent items than novices, but this protection is limited when individuals also view themselves as highly knowledgeable (self-perceived expertise). In other words, while genuine expertise helps mitigate overclaiming, the effect weakens when experts overestimate their knowledge.

The study also found that individuals with more knowledge tend to make faster and more automatic judgments about what they know and do not, leading to fewer false claims. Conversely, less knowledgeable individuals deliberate more and rely on their subjective sense of familiarity, increasing the likelihood of overclaiming. This suggests that experts’ automatic recognition of real terms shields them from overclaiming, while novices’ more effortful processing leaves them vulnerable to errors.

To explore the interaction between genuine and self-perceived expertise, the researchers compared groups with different expertise levels in specific fields, such as medicine and developmental psychology. Across these comparisons, experts were consistently less likely to overclaim than novices. Interestingly, this effect was most pronounced when individuals had high self-perceived expertise, indicating that genuine expertise is most protective when individuals are at the greatest risk of overclaiming.

The meta-analysis concludes that expertise offers some defence against overclaiming but is not a complete safeguard. Self-perception plays a significant role, and when individuals feel highly knowledgeable, even genuine experts can fall prey to the same metacognitive errors as novices. The findings also support a “mirror effect” in cognition, where higher familiarity with real concepts corresponds with better recognition of non-existent terms.

The research demonstrates that genuine expertise can reduce overclaiming, but this effect is constrained by how knowledgeable individuals perceive themselves. Self-awareness of knowledge limitations is essential for avoiding overclaiming, even among experts.

Abstract of the study:

Recognizing one’s ignorance is a fundamental skill. We ask whether superior background knowledge or expertise improves the ability to distinguish what one knows from what one does not know, i.e., whether expertise leads to superior meta-knowledge. Supporting this hypothesis, we find that the more a person knows about a topic, the less likely they are to “overclaim” knowledge of nonexistent terms in that topic. Moreover, such expertise protects against overclaiming especially when people are most prone to overclaim – when they view themselves subjectively as experts. We find support for these conclusions in an internal meta-analysis (17 studies), in comparisons of experts and novices in medicine and developmental psychology, and in an experiment manipulating expertise. Finally, we find that more knowledgeable people make knowledge judgments more automatically, which is related to less false familiarity and more accurate recognition. In contrast, their less knowledgeable peers are more likely to deliberate about their knowledge judgments, potentially thinking their way into false familiarity. Whereas feeling like an expert predisposes one to overclaim impossible knowledge, true expertise provides a modest protection against doing so.