Through their ingenious graphing of criminal behavior over time, Laub and Sampson put the theory of dichotomous criminal careers to rest. There are not two kinds of criminals: one merely badly behaved adolescents who mature out of crime in their 20s and the other inveterate criminals who begin offending in grammar school and malignantly continue in crime until old age. Instead, the offending careers of both groups formed neat, overlapping bell curves. Statistically, early offenders are more likely to persist longer in crime, but after age 50, desistence is the rule, not the exception, for both groups. Thus, chronological age is one factor in desistence, but only one variable among many.