In today’s world, where confidence can sometimes overshadow competence, many people express strong opinions with unwavering certainty—even when they are objectively wrong. This phenomenon, known as the Dunning–Kruger effect, is a cognitive bias in which individuals with low competence in a subject tend to overestimate their own abilities.

Discovered in 1999 by psychologists David Dunning and Justin Kruger, this effect has since become a widely recognized concept in psychology, business, and social behavior. Researchers attribute the bias to a lack of self-awareness, noting that individuals who lack expertise in a particular area also lack the ability to recognize their own shortcomings.

The process follows a predictable pattern. A person learns a little about a topic and experiences an initial surge in confidence, believing they have a solid understanding of it. However, they often fail to grasp the complexities of the subject, leading them to overestimate their abilities. Experts, on the other hand, sometimes underestimate their own knowledge, assuming that what is obvious to them must also be obvious to others.

Donald Trump is one of the most widely discussed examples of the Dunning–Kruger effect in modern politics. Throughout his presidency, Trump frequently made bold claims on topics ranging from foreign policy to economics, often contradicting expert analysis. Despite lacking deep expertise in many areas, his confidence in his knowledge made him a striking example of the phenomenon. Psychologists and political analysts have pointed out that Trump’s self-assured statements, even when factually incorrect, resonated with many supporters who themselves may have been affected by the same cognitive bias.

Another example is Robert F. Kennedy Jr., a well-known figure in the anti-vaccine movement. Despite overwhelming scientific consensus on the safety and efficacy of vaccines, Kennedy has repeatedly questioned their necessity, spreading misinformation about their alleged links to autism and chronic diseases. His stance has been widely criticized by medical experts, who argue that his lack of formal medical training has led him to overestimate his understanding of vaccine science. The Dunning–Kruger effect is evident in his claims, as he continues to challenge established medical research despite lacking the expertise to do so.

The Dunning–Kruger effect is commonly observed in everyday situations. A novice investor may believe they have mastered stock trading after a few lucky wins, only to later realize how unpredictable the market truly is. Similarly, someone with basic culinary skills may assume they are a gourmet chef after successfully preparing a single dish. These instances illustrate how early competence can lead to misplaced confidence, often with humbling consequences.

The effect is frequently seen in public discourse, particularly in areas requiring specialized knowledge. Individuals with minimal understanding of economics or policy may express strong opinions while dismissing expert analysis in politics. In business, employees who lack experience may assume leadership roles without grasping the complexities involved. The effect is also evident in medicine and science, where misinformation, such as anti-vaccine movements, spreads widely due to individuals with surface-level knowledge rejecting expert consensus. Reality television provides further examples, particularly in talent competitions like American Idol, where contestants with limited singing abilities are shocked by the judges’ critique.

Psychologists believe this effect persists because of a fundamental cognitive bias: people don’t know what they don’t know. When individuals lack knowledge in a particular domain, they cannot recognize their ignorance, leading to overconfidence. Additionally, social media amplifies this effect, allowing misinformation to spread rapidly as people assert their opinions without fully understanding the complexities of the subject.

Although the Dunning–Kruger effect can lead to frustration, especially for those on the receiving end of misinformation, it is possible to overcome it. Experts suggest that individuals can counteract this bias by actively seeking feedback, embracing continuous learning, and acknowledging that expertise requires time and effort to develop. Ironically, gaining more knowledge in a subject often lowers confidence, as deeper understanding reveals complexities and uncertainties previously unnoticed.

At its core, the Dunning–Kruger effect is a powerful reminder of the importance of intellectual humility. In an era dominated by misinformation and online debates, valuing curiosity over certainty may be the key to fostering more informed discussions and promoting lifelong learning.