There are various possibilities, some of which are as follows:
1.The happier people are not greedy, whatever they have they are happy with it.
2. They don't get jealous from other's success, they are self-centered in a positive way and give emphasis on their improvement rather than anyone else's.
3. They have less needs and they are satisfied to fullfill them with honesty.
4. They love what they do and don't do anything in order to show superiority, neither less nor more.
5. People even fake happiness, a smile can hide the deepest pains. People show they are happy but sometimes they ain't.
