The ignorance paradox: why those who know the least often think they know the most

Figure 1. Graph used used as a simplification and dramatisation to illustrate the Dunning-Kruger effect (1999), rather than an exact depiction of the research findings.

Have you ever encountered someone who lacks confidence even if you know they’re a good expert? For example, I know a lot of PhD who question their expertise, capacities or knowledge.

On the contrary, have you ever encountered someone discussing a topic they may not fully comprehend? For instance, I remember someone informing and giving dubious advice on mental health to colleagues without having consulted a single book, scientific article, or credible resource on this crucial subject.

Let’s explore the reasons behind these two phenomena from the work of two researchers in social psychology.

1. The aim of the famous Dunning & Kruger study

Before 1999, studies had already shown that people tend to have a bias toward favorable views of their abilities, often seen in phenomena like the superiority illusion (e.g., Dunning, Meyerowitz & Holzberg, 1989 ; Taylor & Brown, 1988). However, the reason of this bias was less well understood.

The objective of the Dunning-Kruger study was to investigate the role of metacognition in self-assessment, examining how people’s lack of metacognitive ability leads to overestimation of their own skills in various tasks.

In other words, their study aimed to examine the relationship between actual and self-perceived competence in objectively measurable areas.

I present this study because, while other more recent studies exist and probably use new and better research protocol, this work has contributed significantly to the understanding of cognitive biases and has implications for education, self-awareness, and personal development.

2. Method and significant results

A. Method

Dunning and Kruger conducted a series of experiments where participants were asked to perform tasks in various domains such as logical reasoning, grammar, and humor. After completing these tasks, participants were asked to estimate their performance and how it compared to others.

B. Key Results

1. Individuals who performed poorly (in the bottom-quartile) in these tasks tended to overestimate their ability and also thought they were above-average, believing they performed better than others
2. Individuals who performed well more accurately estimated their performance
3. Participants in the top quartile tended to underestimate their ability and test performance relative to their peers

Figure 2. Graphs for each study | Source: Kruger & Dunning’s article (1999)

3. Discussion

A. Interpretation

What causes the over-estimation?

Their study pointed to a lack of metacognitive skills among less skilled participants. Improving participant’ metacognitive skills improved the accuracy of their self-appraisals but also their performance on the task. Then, the incompetent participants were no longer incompetent.

So the question is, how can we improve the accuracy of our perception of our abilities?

One of the ways we can gain insight into our own competence is by observing the behaviour of others (Festinger, 1954; Gilbert, Giesler & Morris, 1995, cited by Dunning & Kruger, 1999). However, the incompetent individuals are not able to take advantage of this way. The authors underline that motivational biases, selective recall of past behaviour, the tendency to ignore the proficiencies of others also play a role in the self-assessment.

Figure 3. Illustration found on Pinterest

What causes the under-estimation?

The participants believed that since they did well, their peers probably did too. But when they found out that their peers didn’t do as well, those in the top quartile adjusted their self-evaluations to be more accurate.

In other words, even though they are skilled, individuals don’t recognise that their level of ability isn’t common among their peers. However, using social comparison, they are able to readjust their assessment and perception.

Figure 5. Illustrative adaptation of Einstein’s quote “The more I learn, the more I realise how much I don’t know”.

B. Limits and perspective

Two main limits are underlined by the authors:

• Results could depend on contexts and especially in realms not based only on knowledge but also on physical abilities or artistic abilities for example. A critic of a work of art for instance, will have good assessment skills but not necessarily the artistic skills needed to produce the work.
• Research methodology could be optimised : coincidentally, other research studies have been conducted subsequently, and I’ll provide you with a brief overview in the next section !

III. More recent research

Research following Dunning and Kruger’ study (1999) has delved deeper into understanding the cognitive biases they identified.

Gignac and Zajenkowski (2020) challenge the Dunning-Kruger effect, proposing it may be largely a statistical artifact and not a psychological phenomenon as previously thought (see also Magnus & Peresetsky, 2022).

Pennycook et al. (2017) explored the effect in reasoning, replicating the Dunning-Kruger effect. This effect appears both in estimated performance on cognitive tasks and in self-reported analytic-thinking dispositions, suggesting that a part of the reason why people are biased is that they are either unaware of or indifferent to their own bias.

McIntosh et al. (2019) examines metacognitive insight across simple movement and spatial memory tasks. They found that metacognitive calibration and sensitivity were related to task skill, but their net contribution to the Dunning-Kruger effect was weak. This study suggests that differences in metacognitive abilities contribute to the Dunning-Kruger effect but are neither necessary nor sufficient for it, indicating that the primary driver of the effect is the level of task performance.

IV. How to avoid to be biased ?

While it’s perfectly fine to express interest in a new topic and share information about it, I think there are 2 key aspects to consider:

• Transparency with your audience. This one need to be aware of whether your insights stem from genuine expertise or newfound interest, and from informal or formal knowledge
• Tailoring your communication to your level of knowledge. For example, if you’re not an expert, framing your sentences as hypotheses, possibilities, ideas, or impressions to be confirmed or explored is crucial. Avoid presenting statements as absolute truths or facts unless supported by thorough research, scientific evidence, or verified resources.

Bibliographic resources

• Dunning, D., Meyerowitz, J. A., & Holzberg, A. D. (1989). Ambiguity and self-evaluation: The role of idiosyncratic trait definitions in self-serving assessments of ability. Journal of Personality and Social Psychology, 57, 1082–1090.
• Gignac, G. E., & Zajenkowski, M. (2020). The Dunning-Kruger effect is (mostly) a statistical artefact: Valid approaches to testing the hypothesis with individual differences data. Intelligence, 80, 101449.
• Kruger, J., & Dunning, D. (1999). Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments. Journal of Personality and Social Psychology, 77(6), 1121–1134. https://doi.org/10.1037/0022-3514.77.6.1121
• Magnus, J. R., & Peresetsky, A. (2022). A Statistical Explanation of the Dunning–Kruger Effect. Frontiers in Psychology, 13.
• McIntosh, R. D., Fowler, E. A., Lyu, T.-H., & Della Sala, S. (2019). Wise up: Clarifying the role of metacognition in the Dunning-Kruger effect. Journal of Experimental Psychology: General.
• Pennycook, G., Ross, R., Koehler, D. J., & Fugelsang, J. A. (2017). Dunning–Kruger effects in reasoning: Theoretical implications of the failure to recognize incompetence. Psychonomic Bulletin & Review, 24(6), 1774–1784.
• Taylor, S. E., & Brown, J. D. (1988). Illusion and well-being: A social psychological perspective on mental health. Psychological Bulletin, 103, 193–210.