Physiologists believe that there may be several reasons why some people over apologize. Those could include but not limited to:
Children whose parents teach them that apologizing is a form of politeness. Sometimes, this happens just by witnessing a parent say sorry too much to others. Apologies are like smiles to these folks.
Victims of abuse (emotional, physical, or otherwise) tend to over apologize out of guilt from past traumatic experiences or fear of making others angry.
Another big reason is the fear of conflict, especially women. Women apologize more inappropriately. Psychologist Engel states, Girls are raised with an emphasis on kindness and keeping the peace, more than males. Boys are given much more permission to express their anger and are usually not expected to be as polite and well-mannered. Likewise, women are also more likely to blame themselves for arguments and bad situations than men.
Lack of self esteem is another reason some people over apologize. They feel they are not as valuable as other people or as important, smart. People who are also intimidated by those in authority and want everyone to like them often say sorry for everything. These individuals can sometimes even be overly sensitive and using an apology seems to make things more acceptable in their own eyes.