Confirmation Bias – Has it Happened to You?


It has happened to most of us. Has it happened to you?

That is, has there been a time when data supported a decision you knew to be the right one, but for some reason or reasons you did not get the outcome you expected?

Perhaps you find an exciting investment opportunity like the winners you have spotted before, but it yields mediocre or poor results. Or despite your experience and successful track record when judging candidates, a person you just “knew” would be a good fit turns out to be a bad hire.

With experience can come wisdom… but also confirmation bias.

Confirmation bias is the tendency to pursue and embrace information that matches our existing beliefs. We tend to seek out and enjoy people who write or say exactly what we think. We gravitate toward these sources not for information but for confirmation.

Researcher and writer Thomas Gilovich posits the “most likely reason for the excessive influence of confirmatory information is that it is easier to deal with cognitively.” It’s easier to think what we think!

Yet confirmation bias in business can be especially hazardous and costly to highly-experienced and successful individuals. These minds are adept at spotting patterns, learning from experience, scanning the horizon and connecting the dots. If that describes your talents, take a look at this classic puzzle nicely presented by the “The Upshot.”

If you attempted the puzzle, how did you do?

For those who opted out, in this puzzle participants are given a numerical pattern and are asked to determine the underlying rule. The pattern is quite simple, and participants can test their theories as often as they like before specifying the rule. Yet 77% of participants fail to identify the rule because as soon as they find a pattern that supports their theory they conclude it is the correct rule.

In other words, 77% of participants succumb to confirmation bias.

This is a common occurrence in business. When trying to solve problems or make decisions we overwhelmingly look for patterns that support our theories rather than looking for data that would clue us in that we have missed the mark. And with each piece of data that does not refute our theory, we become more confident in our belief.

This exercise shows how people tend to work at proving their theories right, instead of robustly testing the theories to prove them wrong. Once we have seen enough supporting evidence to confirm we are right, it is far more natural for us to fully embrace our premise or idea.

For instance, maybe we are tasked with determining why a certain work process is not being done well. Is the work done less well by inexperienced employees, or when the machine is overdue for maintenance, or when the materials have a certain characteristic?

We could test all three of these ideas with data. But our natural confirmation bias makes us far more likely to look for evidence that the idea we favor is correct than to look for ways it may be mistaken. So, we start testing the idea we think is most likely and as soon as we find enough evidence to support it, we risk diving into the solution and excluding the other possibilities; and we could very well be headed down a path of action that is sub-optimum for our organization.

In our next post we’ll take a closer look at examples of confirmation bias in the workplace and steps that can be taken to avoid it.