This study was to examine the background and formative factors for delinquency recidivism of 18- and 19-year-old male juvenile delinquents (n = 132) admitted to a juvenile classification home, focusing their family environment, life history and personal factors in particular, based on official records and questionnaire. As the result of analyzing formative factors for delinquency recidivism by use of covariance structure analysis, the two factors such as bad self-image and the belonging to delinquency groups as direct risk factors for delinquency were identified. These two factors resulted from dropping out of school and job, the causes of which were negative factors in family environment or low self-control. Negative factors in family environment and low self­ control were, however, indirect risk factors for delinquency recidivism. As the model for delinquency recidivism formation, the validity of a comprehensive delinquency theory centering on control theory to make a point of the involvement in family, school and workplaces, taking into consideration perspectives such as the theory of self-concept and delinquency groups as a reference group was suggested.

This study assessed the effects of a psychoeducational program designed for improving the social adaptability of social information-processing among young adolescents. A total of 213 junior high-school students (male=105, female=108; ages 12 to 13) participated in this study. The program consisted of a five session social competence educational intervention based on the psychoeducational components of the Social Life (Yoshida , Hirooka, & Saito, 2002, 2005), and the EQUIP programs (Gibbs, Potter, & Goldstein, 1995), conducted as part of regular classes. Findings indicated a significant improvement in the adaptability of social information-processing, as viewed from the causal model suggested by Yoshizawa & Yoshida (2004). The intervention, however, did not show any concurrent inhibition effects on socially delinquent behavior tenden­ cies (SDBT). The results were discussed with respect to the possibility of a time lag in the effects from information-processing to SDBT, and of a developmentally intensified period in their antisocial tendency during this program. Further, we discussed the need to adapt a lengthier or time-unlimited program, with instructors who have mastered the required teaching skills for such a program.

We attempted to examine the effects of adolescent groups on collective problem behaviors. Based on our group process model, we predicted that the more frequently did adolescents engage in collective problem behaviors, the lower was the self-control in their groups (Hypothesis 1), the lower was the adolescents' self-control (Hypothesis 2), and the more strongly they committed to the low-self control groups (Hypothesis 3). We made 130 male students in professional schools describe the groups to which they belonged when they were in high school, and rate their own level of self-control, that of the groups, their level of commitment toward the group, and the frequencies of collective problem behaviors. The results supported Hypotheses 1 and 2. Although Hypothesis 3 was not supported, it was found that the adolescents who strongly committed to groups engaged in collective problem behaviors more frequently.

Careless and hyperactive children tend to become rebellious and defiant against parents and society as a result of being disciplined by them due to a lack of understanding regarding these children. This results in hyperactive children ending up as delinquents. This process is referred to as the march of Disruptive Behavior Disorder (DBD). In longitudinal development studies, impulsiveness, such as rashness, hyperactivity, and lack of concentration are considered to be risk factors for delinquency. On the other hand, in the investigation of human error, individual differences in the tendency for failure is attracting attention and qualitative differences in failure are being discussed. Are there any qualitative or quantitative characteristics in the tendency for failure in delinquents? Is the tendency for failure a risk factor in delinquency? The relationship between tendency for failure and the march of Disruptive Behavior Disorder was examined from this perspective. Participants were 1,842 delinquents in juvenile classification offices all over Japan (1,592 boys and 250 girls). A questionnaire was conducted with reference to DSM-IV diagnostic criteria. Results indicated the following. (1) Tendency for failure of delinquents in juvenile classification offices showed a 3 factor structure: problems in executive functions, action slip, and cognitive narrowing. (2) Path analysis supported causality proposed by the DBD March hypothesis. (3) AD/HD tendency was not directly connected to a tendency for a Conduct Disorder. It was a prodrome of Oppositional Defiant Disorder, and an indirect basis of Conduct Disorder. (4) It is clear that the executive function problems are an important risk factor that directly promotes Conduct Disorder tendency. Based on the above results, it is suggested that the early identification of problems in executive functions and undertaking preventive intervention are essential for stopping the march of Conduct Disorders.