This chapter summarizes the origins and main findings of a longitudinal study in New Zealand expanding four decades. The main focus is on risk factors for children and the possible protective actions which could be implemented when those risk factors are recognized. The findings highlight the importance of early childhood difficulties in self-control, executive functioning, management of emotions and self-regulation. The study allowed to distinguish “adolescence only” behavioral problems from a long-term career of legal difficulties and offenses. The study emphasizes the effects of chronic stress in the life of men and women and the need to find strategies to reduce those stress factors as much as possible. Finally, there is a discussion of some gene-environment interactions and the issue of telomere erosion in chromosomes.