If you're in a good mood - you'll smile more.
And if you are in a bad mood - but you make a conscious effort to smile - your mood will change to become better.
Good mood leads to smiling. And smiling leads to good mood. Its circular.
Similarly - rich friends will lead you to become richer. And once you're rich you'll make more wealthier friends. It goes both ways.
What it sounds like you are saying is that it can, in the right circumstances, create a feedback loop in either direction. And you are right.
With that said, Nico had an excellent point. For most people their friends will include a peer group that almost certainly makes similar incomes to theirs, and for most people you will only really start making a lot of friends at a higher socio-economic point on the ladder when you move up to (or are in the process of moving up to) that same higher point yourself.
If you're in a good mood - you'll smile more. And if you are in a bad mood - but you make a conscious effort to smile - your mood will change to become better.
Good mood leads to smiling. And smiling leads to good mood. Its circular.
Similarly - rich friends will lead you to become richer. And once you're rich you'll make more wealthier friends. It goes both ways.