Myth #1: Dogs have a human appreciation of sharing
Humans can rationalize and appreciate the benefits of sharing. In contrast, among dogs, possession is ten-tenths of the law.
So we should not take toys, bones and chews away from dogs unless we have trained them to accept this form of intervention.
Myth #2: Dogs always enjoy common human physical displays of affection
Humans often show their affection for others by hugging and cuddling them. Dogs simply do not have the limbs and joints to achieve this and so have not evolved to give each other a loving squeeze.
When embraced by humans, many can find this uncomfortable or threatening. The same goes for patting dogs on the head.
Myth #3: Barking and growling dogs are always threatening or dangerous
These are distance-increasing behaviors. The dogs using these signals are chiefly trying to buy space so they can feel safer. All dogs, regardless of their temperament or training, can at times want more space.
They usually try more subtle signalling first, but many dogs learn that subtle signals don't work and go straight for shouting.
Myth #4: Dogs will welcome unfamiliar dogs to their home
Dogs evolved from wolves and are therefore primed to defend what is theirs. They have an attachment to their home territory and the resources within it. Dogs have no way of knowing that the dogs and human we invite around to our home, for example for a play-date, are ever going to leave. They can be forgiven for thinking that this is the way it is going to be from hereon.
So it is to be expected that they will often try to lay out the local ground-rules and put the new arrivals in their place.
Myth #5: Dogs like relaxing as much as humans do
We go to work and go to school, so we greatly value the opportunity to chill out at home and maybe watch TV. In contrast, dogs spend most of their time at home and so value exercise off the property far more than time spent on the sofa.
Myth #9: Dogs are wilfully defiant when they don't do as they are told
Rather than deciding to disobey us, dogs sometimes simply can't do what we ask them to. Either they don't actually know what we're asking them to do, or they have much, much more pressing things to do at the time.
Dogs are not great at generalizing, so just because they sit nicely when asked to in the kitchen when you have treats in your hand doesn't mean they automatically know what "sit" means when they are at the off-leash dog park.