The Jastrow Illusion Moment We Can All Relate

Why the grass is not always greener on the other side


Take a look at the picture below, which one is longer?

First Picture

Yes, you’re right. B looks longer.

What about the following picture?

Second Picture

This time, the upper one, A, looks longer.

In fact, they are the same (stop rubbing your eyes!)

This is known as the Jastrow illusion, discovered by psychologist Joseph Jastrow, who found that when two identical figures are placed next to each other, they appear to be different in size. The cause is still unknown, but the most common explanation is because our brain is confused by the difference in length between the small and the large radius.

Our brain compares the longer radius of B to the shorter radius of A. Thus, B appears to be longer 


So, you may wonder what about Jastrow illusion that has anything to do with your life?

Background story:
I was busy cooking and laying out two same size plates, with the exact same position as the first picture, to fit my stir-fried broccoli and teriyaki chicken, and I saw the illusion. Boom!

This is not about how I learned how to cook, but it’s about the similarity to the “grass-is-greener-on-the-other-side” mindset.

Imagine if you were “A” in the first picture, you would think B is larger and longer. However, If you were “A” in the second picture, voila, seems like you’ve won the race.

Fact is, there’s no race.

You think the person standing next to you has a better life and career, but the person actually thinks you are the one in the front. If you are comparing your weaknesses to others’ strengths, of course you feel defeated. But if you compare strengths with each other (I doubt if it’s even comparable since we all have unique backgrounds and strengths), you all might just be on the same page.

Where you are doesn’t define who you are.

Ask yourself if you’re making the wrong comparison, or is there even a meaning in comparison. Sometimes we just need to pull ourselves away and examine the Jastrow illusion from afar.

Originally published at

The Thrive Global Community welcomes voices from many spheres. We publish pieces written by outside contributors with a wide range of opinions, which don’t necessarily reflect our own. Learn more or join us as a community member!
Share your comments below. Please read our commenting guidelines before posting. If you have a concern about a comment, report it here.

Sign up for the Thrive Global newsletter

Will be used in accordance with our privacy policy.

Thrive Global
People look for retreats for themselves, in the country, by the coast, or in the hills . . . There is nowhere that a person can find a more peaceful and trouble-free retreat than in his own mind. . . . So constantly give yourself this retreat, and renew yourself.


We use cookies on our site to give you the best experience possible. By continuing to browse the site, you agree to this use. For more information on how we use cookies, see our Privacy Policy.