Dogs tend to hang around humans but do they really love us—and what's with the head tilt? Their affability might be due to two genes known to influence sociability in mammals. Gradually genetics turned dogs and humans into best friends.

Dogs have been hanging around humans for at least 15,000 years. But we still haven't worked out the answers to the two big questions – do dogs really love us, and why do they sometimes tilt their heads in such an adorable and ridiculously cute manner?

Dogs evolved from wolves. But if you compare a dog and a wolf they've been both raised in close contact with humans, and there are major differences. First, if you offer both of them food, the dog will come for food, and then hang around for cuddles and companionship. But a wolf will take the food, and then vamoose.

Second, suppose you set up an experiment where the human caregiver appears to be trapped inside a box -they're not really trapped - the dog will offer support and show signs of distress at the plight of the poor human, but the wolf just doesn't care.

It seems that part of the difference is related to two genes called GTF2I, and GTF2IRD1, and these genes are well known to have powerful effects on sociability in mammals, including humans. Modern wolves usually have no mutations in these genes. But dogs can have up to six mutations – and the more mutations they have, the more they love humans.

The current thinking is that way back in time, a few wolves with one or two mutations approached humans for company. And this turned into a beautiful relationship where dogs and humans hang out a lot. Today, dogs and humans work, and play, together - companionship, police work, helping disabled people, protecting humans, pulling loads, and hunting.

And when a dog and their human guardian look fondly at each other, their hormones respond. Their oxytocin levels rise, and that's associated with love and bonding.

So, who even knows what love really is, but it seems that what a dog feels for their owner is pretty close.

So that's Love 101, so now let's look at why some dogs tilt their heads. Stanley Coren, the author of many dog books, explored this.

One suggestion was that the dog wanted to aim one of its ears at their owner – to be better able to hear them. But mostly the dogs' ears were not even pointed at the owner.

Another hypothesis was that the head-tilting was simply the dog letting the owner know that it was paying attention to them.

Another possibility that Stanley Coren came up with was that the long snout, or muzzle, of the dogs could potentially block the view of the owner's mouth, and perhaps simply tilting their head got their long muzzle out of the way. Check it out. Make a fist and hold it up to your nose. Now, look at a fellow human, and you'll notice that you cannot clearly see their mouth – which is where words come from, but also, the centre of most human facial expressions. But when you tilt your head you can now see their mouth. Maybe this is happening in the dog, but we don't know for sure.

A more recent study looked at 40 dogs, and their ability to understand words that described their toys. After an initial three-month training period, where they were taught the names of their various toys, the dogs were tested. The owner and the dog would go to one room, while the toys remained in another room. The owner would then ask the dog to get the specific toy that they named.

Now about 33 of the dogs were pretty hopeless at getting any of the named toys. But seven of the dogs were really good. They could bring back 10 or more toys. Now, initially, the seven dogs could bring back the correct toy 86% of the time, which dropped to 61% a month later, and 57% another month after that. That is pretty impressive. In fact, one of the dogs could bring back the correct toy 54 times out of 59 tests.

Now here’s the weird thing. When listening to the owner's instructions, the gifted dogs would tilt their head to the side 43% of the time, while the regular dogs that couldn't bring back the toy did so only 2% of the time. And the gifted dogs had a preferred direction of tilting, such as to the left or the right, which they stuck with.

At this stage, we still don't really understand what's going on with the head tilt. Maybe the dogs are tilting their head, knowing that they look extra-cute, to make us love them as much as they love us.