It being not only possible but even easy to predict which ten-year-old boys are at greatest risk of growing up to be persistent offenders, what are we doing with the information? Just about the last thing that we should do is to wait until their troubles have escalated in adolescence and then attack them with the provisions of the new Criminal Justice Bill. If this bill becomes law, magistrates will have the power to impose residential care orders. More young people will be drawn into institutional life when all the evidence shows that this worsens rather than improves their prospects. The introduction of short sharp shocks in detention centers will simply give more young people a taste of something else they don’t need; the whole regime of detention centers is one of toughening delinquents, and if you want to train someone to be anti-establishment, “I can’t think of a better way to do it,” says the writer of this report. The Cambridge Institute of Criminology comes up with five key factors that are likely to make for delinquency: a low income family a large family, parents deemed by social workers to be bad at raising children, parents who themselves have a criminal record, and low intelligence in the child. Not surprisingly, the factors tend to overlap. Of the 63 boys in the sample who had at least three of them when they were ten, half became juvenile delinquents—compared with only a fifth of the sample as a whole. Three more factors make the prediction more accurate: being judged troublesome by teachers at the age of ten, having a father with at least two criminal convictions and having another member of the family with a criminal record. Of the 35 men who had at least two of these factors in their background 18 became persistent delinquents and 8 more were in trouble with the law. Among those key factors, far and away the most important was having a parent with a criminal record, even if that had been acquired in the distant past, even though very few parents did other than condemn delinquent behavior in their children. The role of the schools emerges as extremely important. The most reliable prediction of all on the futures of boys came from teachers’ ratings of how troublesome they were at the age of ten. If the information is there in the classroom there must be a response that brings more attention to those troublesome children: a search for things to give them credit for other than academic achievement, a refusal to allow them to go on playing truant, and a fostering of ambition and opportunity which should start early in their school careers.