appologies

I've been asking myself this question for quite a while now. The question is...

"What kind of psychological element makes people over appologize, saying "sorry" when that appology is unnecessary?"

Is it that person's characteristic behaivior? Or as the question asks, there is an existance of a psychological element, or a feeling which leads that person into making that particular action, which in this case is appology.

I wonder which is the case here...hmmm....