Why do we have eyebrows?
The Real Answer
Eyebrows serve two main purposes. Physically, they divert sweat and rain away from your eyes — the arch shape channels liquid to the sides of your face. Socially, they're critical for nonverbal communication. Studies show people have more difficulty recognizing faces without eyebrows than without eyes, which suggests eyebrows are a bigger part of your identity than you'd expect.
Your face has two tiny awnings installed above your eyes, and they're doing more work than most people do at their actual jobs. Remove them and your own mother would walk past you at the grocery store.
The Dunce Dynamics Institute Examines Why People Ask This
Eyebrows are easy to treat as decoration until you see how different a familiar face looks without them. That makes people wonder what those two narrow strips of hair are doing besides giving expressions somewhere to happen.