Patterns of offending

What is the age crime curve (Blumstein et al, 1998)

• Illustrates the relationship between age and criminal behavior 

• Prevalence of offending peaks at about 17 years

• Low levels of criminal activity in childhood, rapid increase in adolescence and a peak during late teenage 

What is Moffitt’s taxonomy of offenders (1993)

• A theory to explain why some people commit crimes and how their behavior changes over time

• Proposed that offenders fall into two main types

As part of Moffitt’s taxonomy, what are adolescence limited offenders (AL)

• Offend during adolescence only and influenced by peer pressure

• Crimes such as shoplifting, vandalism, fighting 

• ‘Grow out’ of offending by adulthood 

As part of Moffitt’s taxonomy, what are life course persistent offenders (LCP)

• ‘Problem’ behavior/conduct disorder in childhood such as aggression, lying and stealing

• Continue to offend during adolescence 

• Offending continues into adulthood 

• Minority of offenders fall into LCP group

Describe LCP offenders

• Exhibit behavioral continuity:

• ‘The best predictor of future behavior is past behavior’

• If someone acted a certain way in the past, they’re likely to act the same way again in the future

• Exhibit heterotypic continuity:

• The type of behavior changes over time, but the underlying problem stays the same

• The person may not always act the same but their core personality trait eg childhood conduct disorder is still there 

Onset of LCP offenders 

• Can manifest as a childhood conduct disorder 

• If behavior is stable and starts early, need to be looking for causes from early life

Neuropsychological functioning in onset of LCP offenders

• Deficits in neuropsychological functioning can manifest in behavior of young children

• Verbal functioning deficits lead to poor problem solving and can impact children’s experience of school 

• Executive functioning deficits include impulsivity and poor concentration

• Can also impact parenting as child’s difficult behavior can evoke poor parenting

What factors can impact onset of LCP offenders

• Ante natal events such as maternal smoking or drug taking

• Birth complications such as oxygen deprivation

• Post natal events such as poor diet and physical abuse

Maintenance of LCP offenders

• LCP offenders will continuously demonstrate anti social behavior and offending

• Negative behavior evokes reactions at school and from peers

• Impact of poor problem solving skills and social information processing on social interactions

What is cross situational inconsistency

• Typically in AL offenders

• When bad behavior doesn’t occur in all settings

• eg may obey rules at school but anti social outside of school

What is Moffitt’s social mimicry theory (1993)

• Mimicking a behavior to obtain a desired outcome

• AL offenders will copy the behavior of LCP peers in order to get what they want 

What is Moffitt’s maturity gap theory (1993)

• Teens want to feel like adults (freedom and independence) 

• However society still treats them like children 

• Therefore they act out and rebel to feel like an adult

• Maturity gap has increased in the past century 

How is the maturity gap and the social mimicry theory intertwined

• Maturity gap leads to adolescents wanting to act in certain ways

• Therefore the AL offenders copy ‘mimic’ of LCP offenders

• Temporary ‘coming together’ of LCP and AL offenders

What are snares

• Life events or consequences that trap a person into a criminal lifestyle

• These block their ability to return to a normal, non offending life

• Common snares include school failure or a criminal record

What is abstention 

• Abstainers

• A small group (6-12%) of teens who never engage in antisocial or delinquent behavior during adolescence 

Why do some adolescents abstain together

• Lack of opportunity to mimic peers, they aren’t exposed to the influences that push typical AL teens

• Personal characteristics, some abstainers are socially isolated or introverted and struggle to fit into peer groups

• They don’t perceive the maturity gap, some teens may be content with their life stage and don’t feel pressure to grow up fast

Evidence for Moffitt’s theory

• Body of research testing Moffitt’s theory

• Research from longitudinal studies generally support Moffitt’s taxonomy

• Other research examining offending trajectories

What is an offending trajectory

• A pattern of how a person’s criminal or antisocial behavior changes over time 

• Researchers use longitudinal data to track how offending starts, peaks and stops

Offending trajectories study, Jennings and Reingle (2012)

• Reviewed 105 studies using sophisticated statistical methods to identify different offender types

• Found 2-4 different trajectory groups

• Commonly found 3 or 4 groups which included non offenders, AL offenders and LCP offenders

• LCP offenders were split into subgroups based on level of offending and age of onset

• Consistent with Moffitt’s taxonomy

What does it mean to compare people in different trajectories

• Once group is identified (AL vs LCP) factors can be compared

• Factors such as background, personality traits and life outcomes

• Helps us to understand why people follow certain paths and what might predict criminal behavior

What are the methodological issues of follow up time

• If a study doesn’t follow people long enough, it might misclassify some offenders

• If follow up time is too short, it might not identify all AL offenders

• Some people look like persistent offenders in adolescence but if followed for longer they may stop offending

• Showing they’re actually AL not LCP

• However some ‘persistent’ offenders might actually be AL but they haven’t stopped offending yet because not enough time has passed to see that change

Offending trajectories study, Keijsers et al (2012)

• N= 503 boys followed from 7-19 years 

• 5 ‘offending’ trajectories found

• Non offenders, 24%

• Moderate childhood only offenders, 29%

• Adolescence limited offenders, 9%

• Serious childhood only offenders, 24%

• Serious persistent offenders, 13%

Offending trajectories findings, Keijsers et al (2012)

• Found that non offenders had good quality relationships

• Adolescence limited, good quality relationships in childhood but deteriorated in adolescence

• Serious persistent offenders, poor quality relationships in childhood, deteriorated even further in adolescence

• Moderate/serious childhood offenders, poor quality relationships in childhood but not clear what prevented them from maintaining offending into adolescence

Offending trajectories study, Wiesner et al (2012)

• N=203 boys, followed from 10-19 years

• 3 offending trajectories found:

• Rare offenders, 68.5%

• Low level chronic offenders, 22.3%

• High level chronic offenders, 9.2%

Offending trajectories findings, Wiesner et al (2012)

• Compared the 3 groups of trajectories:

• High level chronic predicted by higher levels of childhood antisocial behavior, eg childhood attention problems

• Low level chronic predicted by higher levels of child attention problems

• No predictors differentiated between 2 chronic offender groups

• Association with deviant peers was associated with levels of offending within each group

Male vs female trajectories study, Fergusson and Horwood 2002

• Examined this issue using data from birth-21 years

• Found 5 groups including:

• Low risk of offenders

• 3 groups of adolescent-limited offenders (differed by age of onset)

• Chronic offenders

Male vs female trajectories findings, Fergusson and Horwood 2002

• Females are more likely to show low risk and early onset adolescent limited offending

• Males are more likely to show late onset adolescent limited and chronic offending trajectories 

Abstention study, Piquero et al 2005

• N= 1,685 aged 17

• 1,454 offenders

• 231 abstainers

• Collected data on delinquency, peer association and peer involvement

Abstention findings, Piquero et al 2005

• Found that abstainers tend to:

• Have lower proportion of delinquent peers

• Have higher proportion of prosocial peers

• Have greater attachment to teachers

• Abstainers are not socially isolated or troubled/sad introverts

• Good compliant students