The purpose of this study is to analyze delinquents’ response distortion in four questionnaire survey data. Delinquent boys from police samples were compared with ordinary junior high school boys who reported a similar number of delinquent acts as the police sample delinquent boys. Juvenile classification center (JCC) samples were compared with police samples, and juvenile training school (JTS) samples were compared with JCC samples to find out what kind of questions are distorted and which samples are distorted the most.

The proneness to delinquency increases from school samples to police samples to JCC samples to JTS samples in this order. Therefore, the social maladjustment (to family, school, workplace) and psychological problems (personality, attitude, self-concept, norm) are supposed to be more difficult in that order, too. The questionnaire survey, however, sometimes showed responses contrary to our expectation, such as questions concerning adjustment and psychological problems.

The results are as follows.

The police samples and the JCC samples distort their responses to show that they have a more positive personality, attitude and adjustment to social organizations. The JTS sample seems to show some distortion. The degree of distortion is biggest among the JCC samples because they are waiting for the Family Court decision on their disposition; therefore, needing to show themselves as positive personalities.

On the items of the questionnaire, responses to face sheet items and other fact-finding items are not distorted, but on the items asking about past experiences in the family, school and workplace, the tendency is to answer about past experiences with positive images. On the items asking about their personality and attitude, they answer that they are not rebellious, obey their parents’ instructions and have acceptable personalities. They are sensitive to words such as parent and teacher, who have some kind of authority, and respond that they respect and rely on them. The most distorted responses came from the moral survey items. They show themselves as strict moralists. That is a rather natural inclination for them as they fill in questionnaire sometime in the law enforcement process.