Your dog may be a great companion. You may hunt together, play together, eat together, even sleep on the same bed together. Yet, although you and your dog may share life, you will never share a laugh. As far as we know, humans are the only creatures of God who enjoy humor.
Laughter is a distinctive of human beings.
Laughter also can tell something about you. Show me what amuses you, and I can make a good guess about the sort of person you are. If you laugh at filthy stories, you give yourself away. If you scoff at virtue, you have embraced vice. If you laugh at another's failure or misfortune, you have a cruel streak inside of you.