Can You Believe Your Eyes?

Knowing what you don't know, improving negotiation decisions.

“My favorite bias is the ‘I’m not biased’ bias, in which people believe they’re more objective than others. It turns out that smart people are more likely to fall into this trap. The brighter you are, the harder it can be to see your own limitations. Being good at thinking can make you worse at rethinking.”

— Adam Grant (from Think Again: The Power of Knowing What You Don't Know)

“We can be blind to the obvious, and we are also blind to our blindness.”

— Daniel Kahneman (from Thinking, Fast and Slow)

Check out the two parallel lines in the diagram (I’m a writer, not an artist!) above. Now here’s your quiz: Which of the two lines is longer?

Once more, look at the lines closely. Is line B longer than line A, or vice versa?

Perhaps you’re familiar with this bit of optical hocus-pocus, commonly known as a version of the Müller-Lyer illusion. Here, the arrowheads hinder us from accurately gauging the lines’ lengths. That is — you guessed it — the parallel lines are the same, but the orientation …