The biggest (and well deserved) popularity as a "family" dogs are retrievers (Golden and Labrador). Due to its sociability and friendliness — sometimes even somewhat excessive, they are well suited for families with children: the Retriever will be a great playmate for your child. However, very young children to better communicate with the dog under adult supervision from the excess energy the dog may accidentally push or knock over the child. However, the fact that the dog will show aggression, should not be afraid. On a stranger, he may bark, but in General, according to him, the people meant to be friends with them, play and collaborate: retrievers make excellent dog helpers (such as guides).
To my mind, I suppose it is a dog also. Although, any animal, which lives next to you, tries to be friendly and to show you all its love and loyality. If you love an animal with all your heart and you are loyal to it, then such animal would love you, and ofcourse, it would be friendly. And the dog is such an animal, who loves his master no matter his attitude towards this animal. It loves you sincerely and devoted to the people, whom it lives with. And it meets all the members of its familly very friendly and happily.
Also think, that it's dog. It's most sincere and devoted creature. I love them for their selfless dedication, loyalty, for they love us, there is always greeted with joy, with tenderness look in his eyes, ready forgive us in bad mood, go there is always in any weather and any time of day, and I think, that with age, dog can understand lot of question master, sorry, dog can not answer. Of course, dog's behavior depends on how it was educate. But in family, where animal is love - in return receive lot of love and fidelity.
Human’s best friend, very trainable, sociable to humans, can understand commands and obedience. Dogs can identify and remember animal or human faces they’ve met, they can recognise radio, television, etc. They also can be sensitive, jealous and they won’t forget someone hurting them in their entire life.