Focusing on stability and change in criminal behaviors is the basis of this article. After presenting a brief literature review arguing that criminal behaviors tend to show long-term stability rates, the author suggests that criminal behavior stability may be explained by discussing both Gottfredson and Hirschi’s self control theory and Sampson and Laub’s age-based theory of informal social control. Arguing that criminal involvement peaks during late adolescence or early adulthood and contending that many researchers assert that jobs and marriage are effective catalysts for changing criminal involvement, this article tests competing models of stability and change using both Gottfredson and Hirschi’s and Sampson and Laub’s theories. This author contends that Sampson and Laub’s theoretical premise that both individual differences and independent effects of life events are important determinants for future behavior is supported when considering the time-stable differences in underlying propensities to engage in criminal activity. The author suggests that future theoretical research needs to address the underlying causes of persistent individual differences in criminal propensity. Notes, references