As I've said before, confirmation bias is our tendency to cherry-pick information that confirms what we believe in. It means two people with opposing viewpoints read the same book, and come away feeling like it supported their point of view.
A mistake in an equation can ruin a chain of reasoning, and failing to update beliefs in an unbiased way can lead you down the wrong road. If you can't overcome confirmation bias more information won't help you. You'll interpret everything as a supporting case for your current ideas.
If you're reading something and you feel like it supports your side of the argument, try to understand the opposing point of view, and do as Charlie Munger does.
I never allow myself to have an opinion on anything that I don't know the other side's argument better than they do. – Charlie Munger
To understand confirmation bias, it helps to see it in action. One experiment rounded up a group of Stanford students who had opposing views on the death penalty. Half were in favour and half were against.
The participants read two studies. The first supported the death penalty and the second called it into question. Both studies were fake, filled with statistics to support their case.
Bottom line: people in favour of the death penalty found the first study convincing and the second unconvincing. People who were against capital punishment felt the opposite.
At the end of the study, the two groups were again asked about their views on the death penalty. Both supported their original view more.
Understanding opposing views only helps if you can overcome confirmation bias, otherwise you're digging a deeper hole. For someone who likes to read and thinks they are pretty open-minded that's a scary thought. I herald people who are well-read but if aren't overcoming confirmation bias all they're doing is overcommitting to whatever they already believe in.
So, we shouldn't read what we disagree with. We should come up with the strongest version of the opposing argument then updating our belief based on that. And don't be afraid to say I was wrong. If you can say you were wrong, then you can start figuring out what it takes to be right.
Most of us have an opinion on everything, how many of us do the work to earn that opinion?
It's hard work reading up on a topic, reading the for and against arguments and then weighting up the probability that your position is the right one. It's much easier to fool yourself into believing that you did the work and then never bothering to see if you were right in the first place.
Take the time to understand the problem before you come up with a solution.
And maybe, just maybe when someone asks you about a topic that you've only heard of via 15 second news bites, don't have an opinion. Just say I don't know or I'm still forming an opinion. Don't be a chauffeur and memorise opinions designed for applause. Know why you're getting to the answer, not only how to get there.