But I do keep seeing people post in all sort of Internet comment sections, complaining that somebody else mentioned the DK Effect but “it is just statistical noise.”
Discourse reminded me that we discussed it here on PS several years ago—but I’m curious as to whether there any new insights on this.
As a classroom professor long ago, I’m convinced that the Dunning-Kruger Effect is real. I saw it often, especially in grade C and D students who were convinced that they were really B students. Yes, I think there are plenty of contexts where DK is a casually applied description and there is a lot of statistical noise. But more rigor can be applied.
This paper from a few years ago has numerous references to the psych literature and then some EEG data that looks at the specific role of episodic memory in over- and under-estimators.
Dunning and Kruger also used what they coined “reach-around-knowledge” to explain low performers’ inflated belief in their abilities, which refers to a person’s unique knowledge gained from previously participating in a similar task to the task presented and generalizing their past experiences to the current experience (Dunning, 2011) (for alternative views of the DKE, see Gignac & Zajenkowski, 2020; Karjc & Ortmann, 2008; Kreuger & Mueller, 2002; Mahmood, 2016; Sullivan, Ragogna, & Dithurbide, 2018). Although the concept of “reach-around-knowledge” is not operationally defined and lacks a substantive construct grounded in cognitive psychology, it nevertheless provides a useful platform from which to expand into the theoretical constructs of memory. “Reach-around-knowledge” refers to changes in current behaviour based upon prior experience, which is fundamentally a defining feature of memory (Rudy, 2013), and as such, it recognizes a key role that memory processes may play in contributing to this metacognitive illusion.
I haven’t delved more deeply into more recent research but it is a bit ominous IMO that the EEG memory paper has been very poorly cited. However, the DKE is sufficiently accepted by enough scholars that it has recently been subjected to a twin study (abstract and highlights below). These papers are all in a specialized journal, Intelligence, that I don’t know.
Highlights
• The Dunning-Kruger effect (DKE) is well-known yet methodologically critiqued.
• A proposed mechanism for the DKE is metacognition.
• The current study decomposed a measure of metacognition in a large sample of twins.
• Results indicated patterned heritability estimates across IQ quartiles.
• A pattern in heritability may validate the proposed mechanism of the DKE.
Abstract
Metacognition is a process that relates to thinking about thinking. Observed variation in metacognitive processes related to intelligence have often been referred to as the Dunning-Kruger effect (DKE). The DKE describes how individuals often overestimate their competence in a field where they lack expertise, while experts tend to slightly underestimate their competence. Applied to general intelligence, the DKE suggests discrepancies between self-assessed intelligence (SAI) and objective measures of intelligence. Recently, however, the methods used to assess the DKE have been subject to critique. The current study innovatively assessed the DKE by using a mechanistic and genetically informed approach. ACE decomposition models were estimated on a large sample of twins (n = 920; [nMZ = 388; nDZ = 532]) drawn from the restricted version of the National Longitudinal Study of Adolescent to Adult Health. Findings illustrated that about 44 of the variance in a traditional measure of the DKE (difference scores: SAI – objective IQ) was accounted for by genetic factors in the full sample. However, the pattern differed over quartiles of objective IQ where genetic factors accounted for less of the variance in the lower quartiles (about 30 ) and increased to over 75 % of the variance in the highest quartile (remaining variance was due to nonshared environmental factors). Limitations notwithstanding (including a weak and relatively isolated DKE), the current study adds potential support for the validity of the DKE.
I would certainly like for the DKE to be true, since like everyone else here I come across many examples online where some people vastly overestimate their knowledge of certain subjects. Anecdotally, that portion of the effect seems true for at least some people.
Nedelek (2025) is a good paper from my perspective, in that I could easily reproduce their method if I had the data. An R^2 = 0.068 is nothing to get too excited about, but then this is only a very rough measure of intelligence so maybe that is to be expected.
My understanding of DK is that the difference is between those who are knowledgeable and those who are not - and intelligence is not expertise. If we could see a study pitting experts and non-experts I think we might see a much stronger effect. It would also be a really difficult to conduct, but we see examples regularly on the Internet of self-proclaimed experts arguing with those who really know.