Cliques among the youth in church?

I remember growing up when I was a kid there was this one church me and my family attended in Longview, WA, where among the youth there, there were 4 teenagers who seemed to have formed a little clique amongst themselves. They acted snobby and didn't talk to anyone else but themselves. They excluded other people from their little circle all the time. I was a 9-year-old girl at the time and I was struggling with my autism and making new friends. They didn't treat me nicely. I guess they thought I was strange? I did actually try to get to know them and hang around them, but I guess I wasn't cool enough for them because they excluded me too!

Of course this angered my mom. She told me she thought they weren't nice kids and that I should stay away from them. She told me she thought one of the girls had a mean streak. So I did stay away from them.

What do you think about young people in churches forming cliques among themselves and excluding others from their little circle? Do you think that is not very Christian-like behavior?