Why we think we know everything, a cognitive scientist explains

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How does a toilet work? 

You might think you know how this everyday object functions but it's also likely you only think you know because of humanity's tendency to overestimate our knowledge of how the world works, argues Steven Sloman, a professor of cognitive science at Brown University and co-author of The Knowledge Illusion. 

Sloman asked The Current's host Anna Maria Tremonti the toilet question and her answer worked with his book's thesis about how our concept of how much we know is inflated. 

"We think we know a lot more than we actually do," Sloman tells Tremonti. 

In his book, co-authored by Philip Fernbach​, Sloman argues that most of us know very little about how every day things work, what sparked events in history and how influential people have shaped the world. 

Instead, we succeed in life because understanding is stored in the "community of knowledge" — that is, because other people know things, we don't need to know everything and we just assume we do.

That's why some of our best work is done when we work in groups and it's the reason collaboration has lead to amazing works from beautiful music to cutting edge technology.  

No excuses in politics

However, he says the one place where the hubris about what we know is not forgivable is in the political domain.

"When we have not only political leaders, but voters, who think they know things when they don't, then there's a problem." 

Sloman says humans need to fight our tendency to want to be experts in everything.  

"I think step one is to admit our lack of knowledge and to reduce our hubris," he says. "To accept the fact that we don't know everything and to accomplish things we have to make use of the people around us."

The secret of knowledge, Sloman points out, is knowing what we don't know.

"It's often obvious to us what we do know. After all, we know it, we're thinking about it," he tells Tremonti. "What's not so clear is what we don't know. And so the secret of success is accessing the information that we really need."

Listen to the full conversation at the top of this web post.

This segment was produced by The Current's Liz Hoath.