This is also why older siblings usually increase their negative behaviors shortly after the addition of a child into the family. Newborns demand a great deal of attention, so siblings inevitably get less attention than before. The older siblings, then, do what they ve already been taught to do. Just scream, hit, defy, or misbehave and parental attention is forthcoming. It works every time.
Young children are naturally quick learners.
We must be careful what we teach them. Yes, we teach them to do that. Another powerful negative attention feedback loop is complete. As crazy as it sounds, you must remember that it is natural for us to focus on the negative and reinforce these negative behavior patterns. Parenting is an impossible job to always do well.