Birds of a Feather Flock Together.

Is the old adage true? Do individuals of like character tend to stay together?
A friend of mine had a small gathering over the weekend and I was invited. When I got there and started mingling with the other guest I quickly found out everyone there had issues. One of the guest is on medication to help him with his abandonment issues, another is on medication for depression, another has self esteem issues, and another one brought her gay boyfriend and she really didn't have a clue he was gay. Through out the night I kept meeting people with similar issues, luckily it wasn't a big party.
So I started thinking, if all of the host's friends have issues and the saying is true, am I as bad as these people? And if I am, are my friends a good representation of who I am?