Terrie Moffitt's developmental theory of crime
In 1993, American psychologist Terrie Moffitt described a dual taxonomy of offending behavior in an attempt to explain the developmental processes that lead to the distinctive shape of the age crime curve. Moffitt's original statement of the theory is one of the more important articles in criminology with 2,792 citations. She proposed that there are two main types of antisocial offenders in society: The adolescence-limited offenders, who exhibit antisocial behavior only during adolescence, and the life-course-persistent offenders, who begin to behave antisocially early in childhood and continue this behavior into adulthood. This theory is used with respect to antisocial behavior instead of crime due to the differing definitions of 'crime' among cultures. Due to similar characteristics and trajectories, this theory can be applied to both females and males.
Antisocial Personality Disorder
is recognized by the DSM-IV. It is a disorder characterized by a severe disregard for the rights of others. In most of the studies described below, individuals who exhibit antisocial behavior, but have not been diagnosed with ASPD, are used as subjects.Age and Antisocial Personality Disorder
The number of arrests spikes in adolescence, but subsequently declines. This spike leads people to wonder whether more offenders are appearing or more offenses are committed by the same few offenders. Evidence shows that there is an increase in both. The most persistent 5% of offenders are responsible for more than 50% of known crimes committed.Several experiments have been conducted to investigate the relationship between extremity and stability of offenses. In one such experiment a group of third grade boys was studied. Out of the most aggressive 5%, 39% of them scored above the 95th percentile on aggression ten years later, and 100% of them were above the median.
Aggression and antisocial behavior in a child is a predictor of adult antisocial behavior. Some 'difficult' children exhibit behavioral problems due to neurological dysfunctions. One study looked specifically at neurological damage and infant behavior in 66 low-birth-weight infants from intact middle-class families. These children exhibited traits such as immaturity, overactivity, temper tantrums, poor attention, and poor school performance. Each of the previous traits listed has been linked to antisocial behavior later in life. However, these children were not followed up with later in life to ensure their trajectory into crime.
Continuity and Stability of Antisocial Behavior
The continuity and stability of antisocial behavior lies at the root of Moffitt's theory. The Adolescent Limited offenders exhibit antisocial behavior without stability over their lifetime, while Life-Course-Persistent offenders typically display antisocial behavior from very early ages. Biting and hitting as early as age 4 followed by crimes such as shoplifting, selling drugs, theft, robbery, rape, and child abuse characterize a life course persistent offender.Donker et al. presents a test concerning the prediction on the stability of longitudinal antisocial behavior. Two types of antisocial behavior were measured: covert, or behavior that focuses on deceit and theft, and overt, or behavior that involves direct confrontation and the threat of physical harm. This experiment documents subjects during three main periods of their life: childhood, 6–11 years of age, adolescence, 12–17 years of age, and adulthood, 20–25 years of age. Offenders that begin to show antisocial behavior in childhood that continues into adulthood are what Moffitt considers to be life-course-persistent offenders. Their delinquent behavior is attributed to several factors including neuropsychological impairments and negative environmental features. Moffitt predicts that "…estimates of the individual stability of antisocial behavior are expected to violate the longitudinal law, which states that relationships between variables become weaker as the time interval between them grows longer."
The original sample of children in 1983 consisted of 1,125 subjects. Three main areas were studied in the subjects: status violations, overt behavior, and covert behavior. Children exhibiting overt behavior were found to have two times greater risk for covert behavior as an adolescent and three times greater risk for it in adulthood. This violates the longitudinal law and proves Moffitt's expectations correct. Further results also supported this violation, but only with respect to overt behavior, not covert behavior.
There is a difference in the continuity of antisocial behavior between men and women as well. In one longitudinal study an entire county's population was followed from age 8 to 48. Only 18% of the women who ranked high in antisocial behavior at age 8 rank high at age 48, while 47% of men stay in the high category. About 37% of both men and women, however, retained low antisocial behavior through age 48.
Life-Course-Persistent Offenders
Biological Risk Factors
The following biological risk factors have been linked to, but do not cause, persistent antisocial behavior throughout the life course.Brain Injury
Brain Activity
Minor Physical Anomalies
Social Risk Factors
In many studies, the individuals displaying antisocial behavior developed in a family exhibiting "deviant behavior," in an "adverse home environment," or in something similar. However most studies do not specify the exact traits that characterize the tested 'deviant' or 'adverse' environment. Many that are cited include abuse, neglect, socioeconomic status, parental antisocial behavior, etc. There is no evidence that social factors, such as these, can induce antisocial behavior without accompanying biological factors.Effect of Biological and Social Risk Factors Together
| Biological | Social |
| Genetic | Abuse |
| Brain Injury | Neglect |
| Brain Activity | Socioeconomic Status |
| Minor Physical Anomalies | Parental deviant behavior |
Moffitt projects that initial biological predispositions combined with an adverse rearing environment will initiate the risk of life-course persistent antisocial behavior. She conducted a longitudinal study in New Zealand of boys exhibiting a range of antisocial tendencies. Of the 536 boys, 75 of them had adverse home environments and neuropsychological problems. Those 75 boys scored more than 4 times higher on aggression than the boys with adverse home environments or neuropsychological problems. LCP offenders in the Pennsylvania study had higher levels of poverty than the control participants, and they had higher levels of neglect than both the control participants and the AL participants. Additionally, twin studies are often used to isolate effects of nature and nurture. In one such study, the highest criminal activity levels were witnessed in individual's whose foster families exhibited deviant behavior.
Genetic and Environmental Interactions
Minor Physical Anomalies and Environmental Interactions
Brain Activity and Environmental Interactions
Adolescence-limited offenders
Although the biological risk factor do not apply to this group, one point worth noting is that the myelination of the frontal cortex continues into our 20's. This continuing development may help to explain why antisocial behavior ceases after adolescence and why such a spike in crime exists there in the first place.Cause
According to Terrie Moffitt, there are 3 etiological hypotheses for adolescent-limited offenders:1. Adolescence-limited antisocial behavior is motivated by the gap between biological maturity and social maturity
2. It is learned from antisocial models who are easily mimicked
3. It is sustained according to the reinforcement principles of learning theory