Eyebrows: An example of how little we know about ourselves

I’ve been reading and writing about eyebrows this week. I’m learning a lot. It has made me think, with amazement, how human beings (like me) are so oblivious to our own biology in so many ways. I mean, eyebrows are just two strips of hair; they’re kind of boring, perhaps even a little gross. Even though I look at eyebrows dozens or even hundreds of times a day, I’ve never paid them much attention before. All this time, I had no idea how important they are to everyday life.

For one, they are crucial for communicating emotion– more so than words. Our eyebrows tell others when we are angry, sad, afraid and happy. We also use them in conversation, like visual punctuation, as well as to convey empathy. And we send specific messages with them; raising our eyebrows quickly, known as the eyebrow flash,is something that cultures around the world do automatically to send signals. The message can be “hello,” or “yes,” or “I’m flirting with you.”

Detail, portrait of a man with raised eyebrows, Giovanni Battista Moroni

Eyebrows talk, and we are very good at understanding what they are saying, without thinking. But there is more. Eyebrows are crucial for us to recognize faces and determine the identity of its owner. That is one reason why we first look at the eyebrows and eyes when we see a face. People’s eyebrows give us even more information – whether they are male or female, and to some extent how old they are.

THICK EYEBROWS ON A YOUNg male

We also seem to read information from eyebrows about people’s personalities, though there is no evidence (and it is unlikely) that eyebrow shape and personality are actually related. We judge a face with thin eyebrows to be happier, weaker, and more intelligent. Thick eyebrows are judged as stubborn, strong, even mean. This makes me wonder if there is a biological reason for people in so many cultures, especially women, altering their brows to make them thinner. Could it be that we are unconsciously changing what our faces communicate to the world?

Female eyebrow, thinned and tattooed

So here I am, looking at my own eyebrows in the mirror several times a day, using them to detect the emotions and identity of the faces of everyone I meet, and moving them up and down and in and out to send signals to people without being aware of it. My mind pays attention to eyebrows when I’m speaking to people and when I’m watching actors on a screen, and registers and understands the signals they convey without my knowledge.

My conscious mind can try to fake emotions using my eyebrows, but this uses a different part of my brain, and like most of us I am not very good at faking it. The movements we make when deliberately “making a face” are faster, bigger, and last longer. Most people have little difficulty telling the difference between when we are faking a frown and when we really mean it.

Studying the science of eyebrows has made it very clear that my brain is causing me to behave in ways that I do not know about. This makes me wonder what else I’m doing that I have no control over. It makes me uncomfortable to think that I’m an animal, a product of evolution, and that I respond to my environment – including other people – in such complex ways without my knowledge.

It is also marvellous to realize how little we understand about our own biology. Eyebrows are right under our noses (well, actually above our noses), are utterly unique to our species, and yet are not fully understood. From a purely selfish perspective, this means there is plenty of intrigue and mystery left to explore, and plenty still to write about.