Are there any studies indicating a correlation between your professional activity and the one of your friends?

Question

To be more precise:

If somebody has a specific field of expertise (e.g. engineer, lawyer) and work in a certain industry (telecommunication, textile) would he be more inclined to become friend (excluding the career networking factor) with somebody who is doing the same type of professional activity?

Thanks for your help.

Answer 1

only because they spend all day together.