practice of intentionally changing the shape of the human skull, once common in some cultures. Head flattening was practiced by a number of North, Central, and South American Indian tribes, particularly before European colonization. It was most commonly accomplished by securing an infant in a cradleboard that had a moveable cover over the forehead; the pressure of the cover, gently and consistently applied over time, caused the child's forehead to elongate, creating a nearly smooth silhouette from the tip of the nose to the crown of the head; flattening could also be achieved by binding an infant's head with cloth. Head flattening appears to have had no effect on an individual's mental capabilities. See also body modifications (body modifications and mutilations).