Confirmation Bias, Our Foundation

This morning my cousin Dan and I biked over to Chloe’s for lunch. Chloe’s is the best inexpensive cafe in Sonoma County, but I’m not going to tell you where it is or what it’s called. Anyway, on the way back I offered a problem for Dan to consider. He’s an engineer and likes to think about key problems. I figured this one would occupy him for a few days.  (As it turned out, he solved it in ten seconds, but never mind.)

Confirmation bias is a trait built into us by evolution. Evidence that supports one of our beliefs we accept as true.  Evidence that disproves one of our beliefs we ignore. That is why hurricanes don’t change the minds of climate-change deniers or the World Health Organization can’t alter the views of those who fear fluoridated water. 

Confirmation bias is universal. One reason we honor science is that science attempts to control this natural bias in how we think. 

Here’s the problem. If confirmation bias makes us unreasonable, why do we have it? It should have been selected against—but it wasn’t. If Darwin was right, confirmation bias has probably been helping us survive and multiply for 100,000 years, since we developed language and arguments. But how can a bias be helpful?

Dan: It helps us work together as a team. Cooperation may be irrational at times, but it made us dominant.