This could be due to different business cultures, uncertain responisiblites, egos, individual levels of training, demotivation, apathy.  And on and on...

So we take them out of work, let the team get to know each other as people first in a relaxed and de-stressed environment.  Together they share a fun team experience and learn about each other.  Once they know each other on a personal level it becomes so much easier to ask for help or for Managers to approach their staff and ask, "Are you OK?".