Both studies used nationally representative samples (2,143 families in 1975 and 3,520 in 1985), and both found an extremely high incidence of severe physical violence against children and a high incidence of violence against spouses. The 1985 rates, however, although high, were substantially lower than in 1975; the child abuse rate was 47 percent lower, and the wife abuse rate was 27 percent lower. Possible reasons for the lower rates in 1985 are differences in study methodology, increased reluctance to report abuse, reductions in intrafamily violence due to 10 years of prevention and treatment effort, and reductions due to changes in American society and family patterns. Most likely the findings are due to a combination of changed attitudes and norms along with changes in overt behavior. The findings also suggest that inroads can be made into the problem of domestic assault through efforts at social and attitudinal change. 3 tables, 16 footnotes, 71 references. (Author abstract modified)