The floortime treatment approach to autism and related pervasive developmental disorders recognizes that all children learn through play. Floortime was developed by Dr. Stanley Greenspan who contends that children can regulate their behavior once they are able to regulate their emotions. Greenspan's floortime is a treatment that does not take a behavioral approach. The play activities are rewarding in nature and the focus is social rather than behavioral. The floortime approach is child-centered and the adult involved with the process follows the child's lead as he plays. Floortime involves observation and gradual interactions that are helpful in shaping the child's behavior. A child may love to line objects in a row and the parent can use this activity as a way to open the doors of interaction. The parent would simply add items to the line of objects at first then gradually begin to alter the activity. He could begin by branching the line in different direction. Later, the parent can make the items walk or dance while encouraging the child to respond or imitate.