Research on maltreatment in the histories of juvenile delinquents, examinations of the delinquent behavior of maltreated youth compared with that of nonmaltreated juveniles, and analyses of the physical abuse of violent delinquents suggest an association between child maltreatment and juvenile delinquency. Methodological flaws and differences among the research efforts, however, prevent firm conclusions. There is inconsistency among behaviors measured and the deeming of a situation 'abusive' or youth 'delinquent,' and many of the studies lack appropriate comparison groups. Some studies' reliance on self-report data may produce inflated estimates of abuse. Hypotheses relate severe physical punishment to later delinquent behavior and posit that delinquent behavior derives from central nervous system disorders caused by maltreatment. Other theories reason that the family conditions that produce child abuse also produce delinquency and that delinquent behavior is a common adaptive response to maltreatment. Other theorized links are that delinquent behavior elicits parental abuse and that juvenile justice practices cause that adjudication of maltreatment victims as juvenile offenders.