The Time Life documentary "Rock A Bye Baby" describes how the sensory deprivation of normal mothering, touch and movement causes permanent brain abnormalities and pathological violence. The single greatest contribution to understanding the mother-infant separation syndrome was provided by Drs. William Mason and Gershon Berkson in their swinging mother surrogate experiments where the importance of body movement (vestibular-cerebellar simulation) in mother-infant bonding was documented. The infant monkeys reared on the stationary mother surrogate developed all of the abnormalities which isolation-reared monkeys develop – depression, social withdrawal, aversion to touch, stereotypical rocking and chronic toe and penis sucking, self-mutilation and pathological violence as juveniles and adults. The infant monkeys reared on the swinging surrogate mother developed normally with only minor stimulus-seeking behaviors, e.g. thumb-sucking. Depression, social withdrawal and avoidance of touch were absent in the swinging mother surrogate reared infant monkeys.