Moffitt (2018). Male antisocial behaviour in adolescence and beyond.” – Article summary

Male antisocial behaviour is heavily concentrated in adolescence. There may be two types of male antisocial behaviour:

1. Life-course persistent antisocial behaviour (LCP)
   This refers to antisocial behaviour that has its origins in neurodevelopmental processes and family adversity. Here, antisocial behaviour begins in childhood, builds persistently and continues into midlife.
2. Adolescence limited antisocial behaviour (AL)
   This refers to antisocial behaviour that occurs due to age-graded social processes that begin with a maturity gap in adolescence and end when social adulthood is attained. Here, antisocial begins in adolescence and ends when social adulthood is attained.

Life-course persistent antisocial behaviour is rare, persistent, pervasive and pathological whereas adolescence-limited antisocial behaviour is normative. For LCP, there first is a neurodevelopmental vulnerability (e.g. cognitive deficit; hyperactivity; difficult temperament) and this is exacerbated by environmental risk factors (e.g. inadequate parenting; maltreatment; poverty). The environmental risk factors includes other contexts with age (e.g. peer relations) and opportunities to learn prosocial skills are missed. The accumulation of risk and missed opportunities lead to a disordered personality and antisocial behaviour.

LCP boys had elevated levels of risk in domains of parenting (1), neurocognitive development (2), temperament (3) and behaviour (4). These risk factors were not present for AL boys. LCP men often have poor work histories (1), interpersonal conflicts (2), low-status and unskilled jobs (3) and a lack of high school qualification (4). LCP men had more suicide attempts (1), worse mental health (2) and worse physical health (3) in their 30s while AL men experienced less severe problems (e.g. alcohol abuse).

Chronic offenders refer to people who commit repeated offences and have several characteristics:

• They tend to have a young onset age (i.e. this predicts higher offending frequency).
• They commit a broad repertoire of crime types.
• They commit a large fraction of the crimes.

The age-crime curve refers to the curve that offending follows over age. Onset of illegal behaviour is typically between ages 8 and 14 years and desistence from offending is typically between 20 and 29 years. The peak age of offending is between 15 to 19 years. During this age, almost 90% of males break laws.

It is possible that AL men are able to profit from opportunities for desistence of antisocial behaviour whereas this is not possible for LCP men due to their childhood which led to antisocial patterns and personalities. However, all men’s offending declines with age. Adult-onset antisocial behaviour seems unlikely to exist (i.e. they all have a history of problematic childhood or conduct problems).

The strongest predictors of persistent antisocial behaviour are individual characteristics (e.g. difficult temperament; neuropsychological deficits). Abnormalities on neuropsychological tests are associated with LCP but not AL. LCP behaviour is thus characterized by difficulties in the brain’s mental functions (i.e. verbal and executive functions).

A gap between biological and social maturation may explain the rise in the age-crime curve during adolescence. This maturity gap is associated with adolescent offending. Snares refer to experiences that can change and make desistance from crime more problematic. This includes addiction, a criminal record, imprisonment and victimization. Adolescent-onset offenders who experienced more snares are more likely to continue offending.

Abstainers from criminal activity may exist due to a lack of maturity gap (1), barriers that prevent them from learning about delinquency (2) and personal characteristics unappealing to other teens that bar abstainers from risk-taking teen groups (e.g. high conscientiousness) (3). Abstainers are typically later in puberty (1), withdrawn (2), shy (3), socially anxious (4), methodical (5), conscientious (6), rational thinkers (7) and good at coping (8). There seems to be an abstainer group characterized by low popularity and low school achievement and one that is characterized by high honesty.