"The Jyvaskyla Longitudinal Study of Personality and Social Development is one of the most important longitudinal studies of antisocial behaviour conducted anywhere in the world. It is one of the very few projects with repeated personal assessments of hundreds of individuals from childhood up to middle adulthood. This outstandingly important project has greatly advanced knowledge about development through life, and especially about the influence of personality on antisocial behaviour and social functioning. It is extremely important to have the major findings from a wide-ranging longitudinal study, which are often scattered over hundreds of articles, synthesized into one book." – David P. Farrington, Emeritus Professor of Psychological Criminology, Cambridge University, UK