If you've ever had a dog (or met one) you'll probably recognize the 'head tilt'.
You know the one. When their eyes seem to widen and they angle their head to the side as if they're trying to look cute so you give them some more biscuits.
Yes, it's possible they have learned by now that when they look extra cute, they get extra treats – but according to a recent study there's also a much sweeter reason.
When we are listening to someone speak, we evaluate more than their words to understand what they're telling us. We listen to the tone of voice and watch facial features, among other things, to infer the other person's meaning. Dogs are no different.
What is different is that many dogs can't see our entire face when they are looking directly at us. This is because of the fact that their muzzles extend from their faces, blocking their view of the lower part of a human face, including the mouth. Stanley Coren, Ph.D., F.R.S.C. hypothesized that this might be a large part of the reason that dogs tilt their heads when we are speaking to them; they are trying to see more of our face to better interpret our meaning.
Try the following simple experiment; hold your fist up to your nose as in the figure here. Now, in effect, you are viewing the world with a head shape that has a muzzle like that of a dog. If you now look at a person's face you will find that the muzzle will block some of your vision, and reduce your ability to see the lower part of the face. Remember it is this part of the face, particularly the mouth region, which is a vital component of human emotional expressions. Next, still with your muzzle in place, tilt your head when you are looking at the face. With this head posture you can now clearly see the mouth region.
Some dogs have flatter faces. Technically they are said to have brachycephalic heads. These would include dogs like Pugs, Boston Terriers and Pekingese. With a less prominent muzzle extension, there should be a reduced amount of visual obstruction, and these dogs would need to tilt their head less. To see if this was the case Stanley Coren conducted a survey on the Internet.
He asked 582 people to complete an online survey about their dogs. Of the respondents, 62% said their dog regularly tilted its head when spoken to.
Crucially, only 52% of the owners of flatter-faced dogs (such as pugs and bulldogs) said their dog tilted its head. On the other hand, 71% of the owners of dogs with larger muzzles (such as greyhounds) reported that their dogs often tilt their heads when spoken to.
52% of flatter-faced dogs is a big number and perhaps it has to do with hearing, or perhaps the dogs are really just trying to look cute. Nonetheless this study is a first step toward finding the answer, and at least we now have a bit of data to work with.