The research design of the Gluecks' study was strong, but the conceptual and statistical analyses were often lacking in methodological and theoretical rigor. Using multivariate analyses the current study found that mother's supervision, parental discipline styles, and parental attachment are the most important predictors of serious and persistent delinquency. On the other hand, background factors (e.g., parental criminality and drunkenness, broken homes, crowding) have little or no direct effect on delinquency, but instead operate through the family process variables. 4 tables, 48 references, 13 footnotes. (Author abstract modified)