News, Science & Research

Study reveals people’s inflated senses of their own knowledge

U. research highlights individual ignorance, points to society’s reliance on group knowledge

science & research Editor
Thursday, March 16, 2017

We may not know as much as we think we do, University research suggests. Our own knowledge may be riddled with holes, but the information contained in many people’s minds forms a vast web of communal understanding, according to Steven Sloman, professor of cognitive, linguistic and psychological sciences. The shared knowledge effect described by Sloman reveals our ignorance as individuals and points to the intellectual strength of groups.

“The Knowledge Illusion: Why We Never Think Alone” — a book co-written by Sloman and released this week — delves into the workings of shared knowledge and its applications in areas like technology, education and definitions of intelligence.

Sloman’s recent research involved experiments that presented people with information about a concept, including a statement about how well experts understood it. When scientists asked participants how well they understood the concept, they gave higher ratings to their own comprehension when they were told that experts have explained it. “People were confusing what other people know with what they know,” Sloman said. “They think knowledge in other people’s heads is in their heads.”

This confusion happens much more commonly than we expect. People will report that they understand the functioning of a simple device, like a ballpoint pen, but when asked to explain how it works, they often fall silent, Sloman said.

The same holds true in the realm of politics: People tend to have strong opinions about Obamacare, but they typically cannot explain the legislation when asked. “I strongly suspect that even Obama doesn’t really understand Obamacare,” Sloman said.

President Trump provides an “extreme example” of the shared knowledge effect, Sloman said. His “knowledge is almost completely illusory. He talks as if he knows everything. … When he’s pressed, he seems to have little or nothing to say.”

The shared knowledge effect is present in all of us to some degree. Humans are collaborative by nature — even kids collaborate more than other primates. “This is a fundamental property of the human mind,” Sloman said. “The mind is a shared entity, and that’s true of everybody.”

Shared knowledge is both a strength and a weakness of the way we think. “It’s a weakness if you overestimate your own knowledge, which is very easy to do,” said Nathaniel Rabb ’15, co-author on one of Sloman’s papers and lab manager at Boston College’s Arts and Mind Lab. Relying on others for information can create an “echo chamber” in which no one has a thorough understanding, Rabb said.

This type of “vicarious” knowledge sets up an “ignorance arrangement” in modern societies, wrote Michael Smithson, professor at Australian National University’s Research School of Psychology, in an email to The Herald. For most of our knowledge, “we don’t need to know what the expert knows, but only which expert to turn to for our purposes.” But this arrangement raises concerns about the power of authorities and our ability to identify valid expertise, Smithson wrote.

We are dependent on our own judgments about the reliability of information. “Think about your reasons for believing someone else who says they understand,” Rabb said. “Maybe they don’t. Take it with a grain of salt.”

The novel part of Sloman’s recent research is that even just knowing that an expert understands a topic inflates people’s sense of their own understanding, wrote Frank Keil, professor of psychology and linguistics at Yale, in an email to The Herald. The expert’s explanation itself is not necessary.

Keil has investigated similar concepts in his own laboratory and found similar effects. “People confuse information stored in their own minds with information they can search for on the internet,” he said. Even the act of using a search engine makes us feel like we understand more than we do, he added.

Sloman’s research “adds another charge to the rap sheet of human cognition,” wrote Ryan McKay, reader in the department of psychology at Royal Holloway, University of London, in an email to The Herald.

But the shared knowledge effect can also be hugely beneficial. “It is a strength if you respect it, as long as you assess the source of information,” Rabb said, offering the example of a physics paper written by many authors. “Not a single one of them knows what the paper is saying, and they did this based on their trust in each other’s knowledge,” he said.

Sloman is currently pursuing research on how we can “improve public discourse by getting people to think outside themselves,” he said. Politicians often focus on treasured values, but directing debate toward the effects of policy may be more productive, he added.

This area of research has an “ever increasing importance in our interconnected world,” Keil said.

Our power comes from other people, Sloman said, and we need to recognize that.

“The practical goal of the research is to reduce hubris, to make people more humble about their level of knowledge,” Sloman said. He hopes the research will encourage people to “be more open and accepting of others’ ideas and feel a greater need to justify their own.”

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