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When Knowledge Leads to Overconfidence

New research shows knowing a little can be dangerous.

Key points

  • A new analysis finds intermediate knowledge leads to overconfidence.
  • It also finds that overconfident people are more likely to have negative attitudes towards science.
  • People who communicate scientific information should focus on offering thorough explanations.
Black Jack/Adobe Stock
Source: Black Jack/Adobe Stock

Misinformation is ubiquitous in our society. We find it in news outlets, on social media, and — for many people — in daily conversations. At the root of misinformation is someone who strongly believes in an inaccurate or flawed assessment of the evidence. Put simply, the person has confidence in their knowledge, even if it is not based on solid facts.

Sharing misinformation is not the only way overconfidence appears in our daily lives. Imagine a new driver, overconfident in their abilities, who makes a poor decision leading to a car accident. Or a student who overestimates their talent and pursues a challenging career, even though they don’t have the skills.

For decades, psychologists have been trying to determine what leads people to have overconfidence despite a lack of knowledge.

A new analysis published this month in Nature Human Behavior takes a deeper look at the phenomenon of overconfidence, how it relates to actual knowledge, and how it plays out in our daily lives.

In the paper, researchers analyze data from three large surveys designed to measure public understanding of science; in total, more than 96,000 people across the United States and 34 European territories participated in the surveys over the course of 30 years. The surveys asked general science questions with three answer options: true, false, and I don’t know.

For the analysis, researchers used incorrect answers as a proxy of overconfidence and “I don’t know” answers as proxy for confidence. In other words, they presumed people with wrong answers were overly self-assured in their knowledge on that topic, and people who answered “I don’t know” were either self-confident enough to admit their lack of knowledge, or under-confident in their answers.

What the researchers found surprised them: people with intermediate knowledge levels demonstrated the most overconfidence. That is, people who had some knowledge about a scientific topic were more likely to answer questions incorrectly instead of answering “I don’t know.” At the same time, they found people who knew nothing about a given topic were more likely to respond “I don’t know,” therefore less likely to demonstrate overconfidence.

The researchers took their analysis one step further to ask how participants’ knowledge and confidence levels impacted their general attitudes toward science. They found people with an intermediate knowledge level and high confidence were most likely to have negative attitudes towards science — no matter the topic.

What does all this mean? The study's authors say this new information provides valuable insights into the most effective ways to communicate scientific information. Communicators should focus on presenting more thorough information to people who already know something about a given topic, they say. Offering incomplete or oversimplified information could backfire by leading to overconfidence and reinforcing negative attitudes toward science.

There are many examples in modern society where this plays out, most commonly in controversial anti-science movements, such as vaccine hesitancy, opposition to genetically modified foods, and public health measures during pandemics.

The take-home message: There is data to back up the proverb “a little knowledge is a dangerous thing.” In this case, the evidence shows that people who know a little about a given topic tend to be overconfident in their knowledge.

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