Rocking back and forth is a common self-soothing behavior used by children who are angry, frustrated, sad, scared or otherwise very upset. This behavior is particularly common in young children who do not yet have the verbal fluency to express their frustrations.
According to researchers at the University of Michigan, body rocking is a common self-soothing behavior between the ages of 6 months and 2-years-old. Most children rock for periods of 15 minutes or less, and this behavior is considered normal as long as it is not accompanied by developmental delays. If the behavior occurs long past the age of 2 or developmental delays are present, there may be cause for further evaluation. The American Academy of Pediatrics recommends that parents ignore such behaviors as long as they are not causing physical injury. In the event that the behavior is too frequent or severe for the parents to ignore, they recommend that any attempt to change the behavior be done with the child's participation and through the use of positive reinforcement rather than negative punishment. In some cases, the child may be just as eager as the parents to break the bad habit and find alternative coping mechanisms rather than rocking.