A friend swears that shark attacks occur much more frequently than they did in the past. He's not sure why. Maybe from a decline in food sources. Or due to changes in migratory patterns.

What he does know is that it's not safe to go in the water. And that "they" (because it's always "they") need do something about those (darned) sharks.

So I sent him a report showing that 2017 was an "average" year for shark attacks, with 88 unprovoked attacks and 5 fatalities, and another showing that 2018's 66 unprovoked attacks was somewhat below average. 

Which didn't go over well. (Yep: I admit I was intentionally poking the bear.) "That report is a bunch of bull---," he said.  "How dare they manipulate the data to suit their own ends?" 

Not long after, he sent me news of a man who was killed in a shark attack off Cape Cod.

"See?!" he said. "Now who's right?!"

He's right in one way. Shark attacks do happen. Every year, sharks kill people. But that doesn't mean the rate of shark attacks has increased.

So why does he think they have? One cause is ever-increasing access to information. When something happens -- especially something we care about or focus on -- we find out. My friend actively looks for news about sharks.

He knows whenever an attack has occurred. 

Confirmation Bias Is Definitely Not Your Friend

That knowledge makes falling prey to confirmation bias even more likely.  Confirmation bias is our tendency to look for and favor data that backs up what we already believe -- and to avoid or look poorly on data that goes against what we already believe.

If I think a keynote went well, I'll pay close attention to great feedback... and ignore any negative feedback. If my friend thinks shark attacks are up, he'll look for reports of attacks... and ignore historical data that disproves his theory.

Confirmation bias starts with forming a hypothesis -- shark attacks are up, people loved my keynote -- and then seeking out data to support that hypothesis. The more strongly you feel about your hypothesis, the more likely you are to fall prey to confirmation bias.

That's why my friend won't go in the water, even though his chances of getting killed by a shark are around 1 in 264 million. (Statistically, he's more likely to be struck by lightning or get injured by a toilet.)

Why, the more strongly we feel about our particular hypothesis, are we more likely to fall prey to confirmation bias?

One, confirmation bias makes us feel smart. If I think doing 100,000 pushups in a year is a good idea and then I see an incredibly fit guy or gal doing pushups, that confirms my hypothesis -- even though there are countless ways to get stronger and fitter. If I believe in pushups and I see someone fit doing pushups...boom: I'm right.

That makes me feel smart.

Because It Also Means You Drug Yourself

Two, thinking I'm right also makes me feel good.

In the book Denying to the Grave: Why We Ignore the Facts That Will Save Us, Jack and Sara Gorman describe research that suggests we get a rush of dopamine -- the neurotransmitter that makes us feel good -- when we find information that supports a belief.

When my friend hears about a shark attack, he gets a rush of dopamine. In a perverse way, it feels good, both intellectually and physically.

He almost can't help it.

And neither can the rest of us. Our egos want to make us feel we're right... and our bodies make us want to feel we're right.

Which makes confirmation bias really hard to avoid, since, as the Gormans write, "It feels good to 'stick to our guns' even if we are wrong."

That's why, if you want to make smarter decisions, don't look for ways to prove to yourself that you're right. Don't look for reasons that you should stick to your guns.

Realize that your mind -- and your body -- will sometimes betray you.

Start with a clean slate as often as you can. Look at all the data. Look at new data. Then make a decision based on what you know now.

And then be willing to revisit that decision when you get even more new data. As Jeff Bezos says, a key indicator of high intelligence is a willingness to change your mind.

We all want to be right.

A good place to start is to entertain the fact that we might, sometimes, be wrong -- at least for now.