What does your yawn say about the size of your brain?

An in-depth study of the act of yawning has revealed some interesting findings...

Updated: 
B7MJYM Close-up of a woman yawning


Scientists have discovered that the act of yawning can tell a lot about the brain.

Turns out that the longer the yawn, the bigger the brain.

Yawns are important for many reasons. For example, they cool the brain, and keep blood flowing.

See also: Are you a psychopath? Your yawns may give you away

See also: What are the common signs of a stroke?