The purpose of this study was to create brief self-report scales to assess individual differences in the sensitivity of two behavioral tendencies in delinquents: delinquency approach tendency, and delinquency inhibition tendency. Through factor analysis, as subscales of delinquency approach tendency, we derived two scales: self-centeredness and fun seeking/reward responsiveness, and as subscales for delinquency inhibition tendency we derived three scales: self-punishment responsiveness, punishment-avoidance responsiveness, and inhibition. The reliability and discriminant validity of these scales was confirmed in the form of correlations with alternate measures. Then, using structural equation modeling, we analyzed the effects of both delinquency approach tendency and delinquency inhibition tendency on delinquent behavior. We found that delinquency approach tendency directly increased delinquent behavior, but strong delinquency inhibition tendency did not cause directly decreased delinquent behavior. However, we found that if strong delinquency inhibition tendency weakened delinquency approach tendency, it had an indirect effect of reducing delinquent behavior to a large extent.

The objective of this study is to establish a framework for understanding the psyche of modern juvenile delinquents, characterized by the keyword "immaturity, " and to find clues for appropriate methods of treatment.

Using juvenile delinquents having significant emotional immaturity as sample cases, I categorized characteristics of their interpersonal behavior. Results indicated that the characteristics of their interpersonal behavior corresponded to those of a typical parent-child relationship. By combining these characteristics, I was able to complete a diagram showing development of each of their object-relations. In other words, problems exhibited by the subject youths could be regarded as emotional problems in accordance with the maturational process of object-relations. Treatment methods that promoted psychological growth of these youths also addressed their emotional problems.

This study conformed to an empirical study of treatment categorized based on the interpersonal maturity theory since it used characteristics of interpersonal behavior as a reference for categorization and obtained similar results of previous studies that concluded that specific and realistic treatment was effective for juvenile delinquents with low interpersonal maturity levels. Also, the present results showed the importance of interactions among group members.