What is Left Gaze Bias? How Does It Relate to Dogs?

By Linda Cole

A recent study by a team of researchers at the University of Lincoln in England have found dogs can see our emotions more than what was once thought. In fact, dogs are unique among the animal kingdom as the only ones who can see and understand our emotions by looking at our face. Dogs have a left gaze bias and can see our emotions.

When we meet another person, our gaze normally scans the right side of their face, as long as they are in an upright position. The left side of our brain controls the right side of the body and the right side of the brain controls the left side. It's the left hemisphere of the brain that controls how we show emotion which is displayed on the right side of our face. The left side of our face shows almost no emotion because the right side of the brain has a different function and doesn't control our emotional state of mind. Looking at the left side of the face is called left gaze bias, or left face bias.

Our tendency is to look on the right side of the face for hints as to how someone is feeling or what their mood may be. We understand how someone is feeling by detecting clues on the right side of their face. We can usually tell right away if they are happy, sad or angry. It's something we all do subconsciously. Somewhere along the line in our evolution, we began a left gaze bias to help us determine how another person is feeling.

The study done in the UK has determined that dogs can see our emotions the same way. Left gaze bias is used by humans only when we are looking at another person. It doesn't hold true if we look at a painting, a pile of dirty laundry, a brand new car or other animals. Dogs are the same as we are in this bias, and so far the only animal that’s been found capable of actually seeing our emotions like other people can.

The researchers, lead by Dr. Kun Guo, studied 17 dogs. Each dog was shown photos of inanimate objects, monkey faces, human faces and dog faces while being videotaped. The dog's eye and head movements were the focus of the tape. When the researchers watched the tape, they discovered all of the dogs had eye and head movements toward the left side of the face (left gaze bias) only when shown human faces. They concluded that dogs have a strong left gaze bias when looking at human faces.

It's believed dogs evolved and developed left gaze bias and can see our emotions because of their long association with us. Dogs learned centuries ago to read our emotions by looking at the left side of our face. The interesting thing about this study is it looks like dogs are one up on us. When the researchers flipped the pictures of human faces over, the dogs were able to distinguish the difference and still showed the same strong left gaze bias. When we look at an upside down face, we lose our left gaze bias altogether.

If you have a dog in the house, try it yourself. Watch your dog's eyes when they look at you. It may be a subtle eye shift to the right, but it is true; they do scan the right side of your face first. So the next time you scold your dog or you are sad because you didn't get that promotion at work, your dog probably does know you are angry or sad even though he won't understand why.

When you factor in a dog's knowledge of body language along with a left gaze bias, it's possible your dog understands more than you know. When he tucks his tail between his legs before you start yelling at him for tearing up the pillows on the couch, he really does know he is in trouble. Forget the yelling and just let it go. The pillows can be replaced but your best friend needs all the love you can give him because he will be there when no one else is, and can tell when you are feeling angry, sad or happy.

Read more articles by Linda Cole