This is the age when the child is beginning to assert his independence. The child may feel that mother is bringing another child home because the eldest is leaving her so to speak. The real problem of these children is that they may feel frustrated if they feel that they are not given enough attention by the parents. Whether true or not they may become convinced that their needs are not being met. On the other hand, having a sibling allows a preschooler to see the world in a different light.
Siblings help children learn how to make friends.
They will learn this through experimenting with each other. They may also have an easier time with social interaction and functioning as a member of a group. They will learn not to be frustrated if they re not the center of attention or if they can t always have their way. Parents can start siblings out on the right foot by introducing the new baby as part of family life. Keep your same routines and rituals.