The reason we as humans love our dogs so much is because they show extreme amounts of gratitude for what they receive. As humans we crave recognition for our actions because it increases our levels of dopamine and serotonin. This is a tribal instinct. For example, when someone or something recognizes our actions it verifies our acceptance as a member of their group also verifying an increased chance of survival. So pretty much if you show extreme amounts of gratitude to people they will love you like they love their dog.