“…The following are some tentative conclusions we may make: (1) Prevalence among normal babies is between 7 and 17~ (Shentoub & Soulairac, 1961, cited in Green, 1967DeLissavoy, 1961;Sallustro & Atwell, 1978); (2) SIB, when it appears, usually develops in normal infants of 7-8 months and disappears by age 5 (Kravitz & Boehm, 1971); (3) SIB appears to occur more frequently in severely schizophrenic children, perhaps as much as 40~ (Green, 1967;Shodell & Reiter, 1968); (4) SIB among the institutionalized retarded ranges from about 8 to 14% (Maisto, Baumeister, & Maisto, 1978;Ross, 1972;Schroeder, Schroeder, Smith, & Dalldorf, 1978;Soule & O'Brien, 1974;Smeets, 1971;Whitney, 1966, cited by Smeets, 1971); (5) the lower the level of retardation, the more frequent and severe SIB is likely to be (Ross, 1972); (6) SIB is often accompanied by stereotyped behaviors, aggression, communication deficits, and neuropathology; (7) the most frequent SIBs are head banging, usually in combination with biting, scratching, gouging, and hair pulling (head banging seems more prominent among males, biting more among females, and gouging more among the blind); (8) SIB is more prevalent among the severely and profoundly retarded than among the mildly and moderately retarded; (9) SIB is unrelated to chronological age beyond 6 years, but little work is available on the retarded below age 6 since this is often the age of admission to large institutions; (10) SIB cases have been institutionalized longer than other residents; (11) SIB rated severe by institutional staff has a longer chronicity than mild SIB.…”