[Psychological theories on delinquency]

The authors review the various psychological explanations of delinquency, based on a psycholgoical etiological approach, considered within three broad categories: 1) Unchanging intrapersonal factors; 2) Changeable intra-personal factors, and 3) Interpersonal factors. For each theory, three criteria of validity have been used, based on the theory explanatory power in relation to: 1) the differential rates of deliquency for various subgroups, and the peaking at age 16; 2) the various forms of delinquent behavior, and, 3) the individual motivations to delinquency. The implications for prevention, of the different theoretical approaches, are also briefly discussed. The interpersonal theories appear to offer the most fruitful research and action opportunities. The practical implications for primary prevention, particularly at the school level, are discussed.