DD13 and DS18 are both fairly introverted, along with me and DH, while DS21 is very extroverted, and dare I say "immature." This absolutely drives DD13 up the wall! She gets SO mad when he acts immature and displays his extroversion.
Are you kids introverted or extroverted? Do they get along with people of the other type?

My husband is an extrovert, my daughter is an extrovert and so is my son. I am the only introvert in the family.

My daughter (18 years older than my son) seems more immature than my son at times and he doesn't hesitate to let her know what he thinks about it. She has always been more impulsive than he is. He thinks before he does anything, sometimes too much.