Children's traits, such as antisocial behavior, are embedded in a matrix that is changing over time. Although the trait score is stable, there are changes in the form of antisocial acts. There can also be subgroups of boys who show systematic increases in mean level of antisocial behavior. Latent growth models were used to demonstrate both changes in form and systematic changes in mean level for a subgroup of boys. The analyses included measures of covariates that were thought necessary to cause these changes. There are also qualitative changes brought about by the presence of the antisocial trait itself (e.g., academic failure, peer rejection, and depressed mood). Factor analyses carried out at three ages showed that, over time, both the changes in form and the addition of new problems are quantifiable and thus represent orderly change.