Developmental criminology

1. Developmental criminology

2. Age, life course and crime • THE DATA • Crime rates rise rapidly through adolescence • Peak in late teens to early twenties • Decline steadily afterwards • How does this square with criminological theory? • Most theories propose that biological, psychological or social factors cause crime • Developmental (age-based) theory suggests that different factors may have different effects at different ages • When a person begins to commit crime • Whether a person continues to commit crime or stops

3. Two explanations for the data – criminal propensity and criminal career • “Criminal propensity” view – Hirschi and Gottfredson • Differences between individuals shape their propensity to commit crime • Propensity fairly stable after age 5; may be affected by external circumstances / opportunities • As offenders age their numbers stay the same, but they slow down • Commit fewer crimes • May mature out of crime • “Criminal career” view – Blumstein and Cohen • Small proportion of offenders commit the majority of crime • Different variables may explain behavior at different ages • Whether (yes/no) someone commits crime • Frequency and duration of criminal activity • Number of offenders goes down over time • Those who keep offending (become career criminals) commit crimes at the same rate as before

4. Research approaches • Criminal propensity -- cross-sectional research • Since age/crime relationship does not vary (after age 5) no need to track individuals over time • Cross-sectional research • Use existing data • Compare individuals one time, retrospectively • Criminal career -- longitudinal research • Follows individuals over time • Allows better study of causation • Cross-sectional only allows correlation studies • Longitudinal establishes order of variables -- which came first • Did a factor believed to affect crime (e.g., age, grades in school, etc.) come before changes in offending?

5. Early research findings • Criminal propensity • Propensity -- number of offenders stable, but they slow down • Findings #1 (Rowe et al) -- criminal propensity trait closely resembled the actual distribution of crime in four cities • Findings #2 (O’Brien et al) -- Differences in homicide rate for youths between 1960 and 1995 • explained by high proportion of births to unwed mothers and few resources available to children • crime thereafter followed the age-crime curve • Criminal career • Career -- number of offenders declines over time, but a small pool (career criminals) keeps offending at the same rate • Findings (Simons et al) -- changes in parenting, quality of schooling and association with delinquent peers come before changes in behavior

6. Cambridge Study -- Piquero et al. • British longitudinal study of 411 males born in 1953 • Followed 30 years, from 1963 to 1993, ages 10 to 40. • Findings (published 2007) • By age 40 most had desisted from crime • Consistent with criminal propensity position • Did not find small subset with permanent high crime rates (note: this was a very small group) • Four key variables distinguish between offenders and others • Low achievement • Poor parental child-rearing • Impulsivity • Poverty • Early prevention crucial

7. Thornberry’s interactional theory –Combines control and social learning • Most theories flawed because unidirectional • Thornberry makes them recursive  and time-dependent • Controls operating through social constraints are most important • Attachment to parents, commitment to school, belief in conventional values • An interactive setting where crime is learned, performed and reinforced • Association with D’s, adopting D values, engaging in D behavior • Delinquent behavior is reciprocal • “Delinquency eventually becomes its own cause” • Delinquency negatively influences attachment, commitment and belief • Few disparities as children age • Early adolescence (11-13): None • Middle (15-16) • Attachment to parents plays smaller role • Delinquent values may solidify – gain influence • Late (18-20) • New control issues in effect • Commitment to conventional activity (work, college, military, family, kids)

8. Sampson and Laub –Age-graded theory of informal social control • Data from Glueck’s 40-year cohort of 500 D’s and 500 non-D’s • Explanation for delinquency centers on family • Erratic and harsh discipline • Mother’s lack of supervision • Parent/child acceptance/rejection • Family factors may be influenced by structural variables • Low SES, crowding • Parent’s criminality • Family size and disruption • Delinquency “closes doors” • Reduces opportunities for positive life changes • Reduces likelihood of positive adult social bonds • Delinquency best predicts adult criminality, but most delinquents don’t become criminals • Interaction between crime & informal social controls continues into adulthood • Change of life course (jobs, marriage, new friends) can lead to increased “social capital” and overcome delinquency’s “closed door” effect • Developing strong social bonds as an adult reduces likelihood of crime and deviance

9. Tremblay - developmental origin ofphysical aggression • Concern with preadolescent development • Aggression develops in first two years of life • Increases substantially from nine months to four years, then rate decreases for most • But for a minority the rate keeps increasing • Theory: aggression may be innate • It’s non-aggression that must be learned • Children must learn alternatives when very young • Not tolerate physical aggression • Reward pro-social behavior • Improve ability to delay gratification • Improve verbal skills