It may start with your 2-year-old clandestinely pinching his newborn sister...but sibling rivalry can last for years when it goes unchecked. When they're small, squabbles about toys, personal space and competitions for affection seem to spark rivalry. When a toy dispute arises, resist the urge to intervene every time. Siblings who try to solve conflicts peacefully among themselves tend to bicker less than those who constantly run to mom or dad, setting up the "bad kid/tattletale" dynamic. Ask younger children to make requests of their siblings nicely: "How do we ask Brother for a turn?" Reinforcing their relationship - using phrasing that includes "your brother" or "your sister" - can help diffuse anger and tension. Establish what is shared and what is off-limits to each sibling, and an egg timer might help when it comes to taking turns watching TV or playing with toys. If disputes arise over what TV shows or movies to watch, then blame the TV instead of taking sides with one child or the other.