While some minor sibling rivalry is normal, a new study suggests fights between teen brothers and sisters can having last effects.
Researchers from the University of Missouri report teens can suffer from anxiety and self-esteem problems even a year after a sibling invades their personal space and privacy.
Issues can include eavesdropping on conversations and borrowing things without asking.
And even though every sibling has uttered the "it's not fair" phrase, major fights about fairness and equality may play a role in bouts of depression.
Experts say parents can help by setting solid house rules when it comes to respect among siblings, like asking permission before entering someone's bedroom and making sure chores are shared equally.