Criminal Careers

Since the early works of Sheldon and Eleanor Glueck, the concept of the criminal career has been well established within the field of criminology. Most generically, the criminal career is conceived of as the longitudinal sequence of delinquent and criminal acts committed by an individual as the individual ages across the lifespan from childhood through adolescence and adulthood. Four key structural elements are defined and applied to the study of criminal careers: participation/prevalence, frequency/incidence, seriousness, and career length (Blumstein, Cohen, Roth, and Visher). Participation is a macro-level measure of the proportion of the population that is involved in offending behavior, while frequency is the rate of offending for those individuals who are active offenders (often denoted as lambda, or l). Seriousness refers to the level of seriousness of the offenses being committed by a given individual, while career length refers to the length of time that an individual is actively offending. When aggregated across individuals, criminal careers typically exhibit a unimodal age-crime curve for the population.

Frequency, seriousness, and career length can vary greatly among individuals, who may range from having zero offenses across the lifespan to having one offense of a nonserious nature to being chronic or career criminals with multiple, serious offenses across a broad span of their lives. In the United States, Blumstein and others (1986) suggested that population-level participation rates vary between 25 and 45 percent, depending on how "participation" is measured. Visher and Roth, in a meta-analysis of studies on both United States and British participation rates, found that the level of participation is about 30 percent for non-traffic related offenses. Averages are higher or lower depending on the measure of participation, which can range from the mild "contact with the police" (e.g., Shannon, 1988, 1991) to the more stringent measure of "convicted of a crime" (e.g., West and Farrington, 1973, 1977).

However, despite this consensus on the definition of the criminal career (and the career criminal) and the aggregate level age-crime curve typically found, controversy has emerged across many other areas within criminal careers research. For example, do juvenile delinquents/criminals comprise a unique segment of the population (e.g., Blumstein et al., 1986) or is delinquency a behavior that is a "typical" part of the growing-up process, from which most adults desist? Are criminal propensities relatively constant across the lifespan (e.g., Gottfredson and Hirschi, 1990) or do they vary with age (e.g., Sampson and Laub)?

Studying criminal careers implies the use of longitudinal panel data. In criminology, this has been difficult due to a lack of available resources, hampering the development of testable theories. As Sampson and Laub point out, "criminology has been dominated by narrow sociological and psychological perspectives, coupled with a strong tradition of research using cross-sectional data on adolescents" (p. 23). This combination of a lack of data and limited theoretical perspectives and methodological techniques has particularly hampered the ability to understand the criminal career, which is both longitudinal and dynamic in nature.