Body rocking, head banging, and head rolling—three rhythmic behaviors that involve stimulation of thevestibular system—were studied in 525 normal children. Data analyses focused on two issues: (1) the prevalence and duration of these habits and their relationship to child and family factors and (2) the hypothesis that children who persistently displayed such behaviors would be reported as developmentally more advanced than “non-self-stimulators”. Body rocking was the earliest to appear and most prevalent of the three habits. Head banging and head rolling had roughly the same prevalence and age of onset. Comparisons of “self-stimulators” with “non-self-stimulators” yielded no significant effects for birth order or SES; only for head banging was a significant (3:1) ratio of males to females found. A comparison of the ages at which 12 “milestones” first appeared supported the hypothesis of developmental precocity for the body rockers and the head bangers, but not for the head rollers.