Population Heterogeneity and State Dependence: State of the Evidence and Directions for Future Research

Criminological research has consistently uncovered a positive correlationbetween past and current criminal behavior. Continuity in offending overtime can be attributed to at least two processes—populationheterogeneity and state dependence. A population heterogeneity processattributes stability in offending over time to differences in ananti-social characteristic (self-control, impulsivity, psychopathicpersonality) across persons that is established early in life andtime-stable thereafter. An implication of a population heterogeneityexplanation for continuity in offending over time is that the anti-socialcharacteristic is likely to have reverberations throughout life, takingmany manifestations later in life (unemployment, drug addiction, maritalinstability). Any observed correlation between these later life events andcriminality, therefore, is spurious rather than causal, due to the factthat they are all the effects of a common cause. A state dependenceexplanation, in contrast, attributes observed stability in criminaloffending to a process of contagion. That is, criminal behavior has agenuine causal effect on subsequent criminality by eroding constraintsand strengthening incentives to crime. The implication of a statedependence process is that criminal conduct may be influenced by laterlife events. In this paper, we draw a connection between populationheterogeneity and state dependence processes and extant criminologicaltheory. We also review the literature that has investigated theplausibility of these two processes. Finally, concluding that weknow very little about them we make recommendations for future researchon population heterogeneity and state dependence.