As they approach their first birthday, babies begin experimenting with everything they find: dropping, rolling, shaking, throwing, submerging, or waving objects. Although their behavior may resemble random play, babies make important discoveries about how the world works when they hurl their cereal bowls, empty out wastebaskets, or rummage through the contents of open drawers.
Shelov, S. P. (Editor-in-Chief). (2004). Caring for Your Baby and Young Child: Birth to Age 5. The American Association of Pediatrics. Revised edition. New York: Bantam Books.