Why do smart people make misteaks?

Neuroscience researchers are intrigued by the idea that we have two primary ways of thinking: one guided by encoded evolutionary info controlling our fight or flight response to stimulus and one that is guided by principles of rationality and reason. Most people think they are using thinking style two–being rational, disciplined, deliberative. The fact is, though, that all of us are trapped and victimized by thinking style one often without being aware of it.

brain gears

Style one arose to help us survive, so it is reactive and semi-automatic. It helped us escape danger while moving through the tall grass on the open savanna. It focuses on pattern recognition and response, almost antithetical to the kind of probabilistic thinking we need to thrive in the 21st century. These automatic responses to stimulus create what we call cognitive biases,  habitual ways of thinking that may have helped us survive in the distant past but are no longer useful for meeting today’s challenges.

In fact, cognitive biases are not only unhelpful; they can be dangerous. They can get in the way of rational deliberation and trip us up by causing us to believe we have the right answer when we do not. And these biases often kick in below the level of conscious thought, making them hard to spot.


Here’s a cognitive issue most of us run into on a regular basis: Imagine that I have a ball and a bat for sale. The bat costs $1.00 more than the ball, which costs a nickel. So what do the two items cost together? Most of us jump straight to $1.05 for the two together, but that’s not the answer. That’s how much the bat costs. The bat costs $1.00 more than the five-cent ball so the two together cost…

1.05 + .05 = $1.10

And that is the difference between automatic thinking and critical thinking. We’ve been taught to use a heuristic (or rule of thumb) when dealing with word problems: focus on the numbers. Here, though, the heuristic fails us because we aren’t focusing on the numbers themselves, we’re focusing on their relationship to each other.


I recently saw a list of over two hundred cognitive biases put together by Wikipedia, but don’t get disheartened. You don’t have to memorize a long list of terms and definitions. Simple awareness is a good start. Coming up, I will concentrate on a half dozen or so of the most common biases and point out effective ways to check their influence. Look for a discussion of specific biases in a later post. Also, please feel free to let me know about areas of critical thinking that are of special interest to you.


Author: Craig Butcher

Craig Butcher is an award-winning educator who has taught critical thinking skills for more than two decades. In addition, he has worked on Capitol Hill as a congressional staffer and has been a top-rated broadcaster.