In any social group, organization or even in community, have you ever notice at times when someone is alone or left out by themselves? What is your first reaction? I am sure it is not hard to realize that many times our first thought would be: something is not right with that person that is singled out. Perhaps he or she is angry with the group. Maybe he is withdrawn, does not like to be in the group. Maybe she is a loner….. maybe, perhaps, maybe……. The focus is always that single person. Have we ever stop to think that perhaps the problem does not lie only on him or her? What about the majority, i.e. the group? Don't they have a part to play too? Have they try to reach out to that person? Perhaps unconsciously because of their "group", they excluded him? Instead of judging right away that that person has a problem, perhaps we can stop to think if the problem lies also on us. A little smile, a little word of acknowledgement or encouragement, at times even a hug can open up the wonders in every person. It takes both hands to clap. At times we can be the single person, and another time, we might fall into the majority. Don't think that only the single person is closing himself/herself up to the group. Even a group can be exclusive and closed themselves to the "outside" world.
I am not a psychologist or sociologist, but this is just my personal thoughts.