The openness of your network is the #1 factor in your career — The Mission — Medium

The bottom line? According to multiple, peer-reviewed studies, simply
being in an open network instead of a closed one is the best predictor
of career success.

We’ve evolved to put people
in our ingroup and outgroup. We put most people in our outgroup and a
few people in our ingroup. It determines whether we care about others.
It determines whether we support or attack them. The process is a
byproduct of our evolutionary history where we lived in small groups and
strangers we didn’t know well weren’t to be trusted.

– David Rock