If You Fall for This Optical Illusion, It Means You Spend a Lot of Time Around Buildings

April 22nd 2017

Willie Burnley Jr.

Have you ever wondered how growing up in the city, or in suburbia, or in another densely populated areas has affected the way your brain has developed? Well, thanks to psychologists and the magic of geometry we may have one answer.

One of these effects can be seen when a person looks at the lines above — courtesy of Pacific Standard’s Lisa Wade — and asks themselves which is larger. If they are from an area with traditional, linear buildings — "carpentered areas" — they’re more likely to say the one to the right, when, in fact, both lines are the same length.

The illusion isn’t based simply on length, according to psychologists, but actually is a matter of our brain applying depth to two-dimensional Müller-Lyer lines. They theorize that because so many of us have grown accustomed to viewing a world of linear buildings our brains look at the right line, which resembles two walls converging far away, and assumes that it longer than the line that resembles two two walls converging closer to our point of view.

Thus, they implicitly argue, people such as hunter-gatherers or those who’ve lived away from human-made buildings would not succumb to the Müller-Lyer illusion, because their brains wouldn’t know to apply the depth we associate with building corners onto the lines. If you don’t believe it, use a little scientific method and try it with friends.

h/t Pacific Standard