If your younger child often seeks attention from an older sibling, only to be ignored, try rewarding your older child for interact with their younger sibling. Have the older child "babysit" for a set period of time, and ask him or her to do an activity with their sibling. Reward the "babysitter" with a small payment or desired item. These small, regular chunks of time where the younger child receives attention should reduce whining and other attention-seeking behaviors.