User:Emilyemorris/sandbox

Terrie Moffitt's Developmental Theory of Crime

Terrie Moffitt, a college professor, developed this theory on adolescent-limited and life-course-persistent offender antisocial behavior in 1993. She proposes that there are two main types of antisocial offenders in society. Adolescent Limited offenders exhibit antisocial behavior only during adolescence. Life-Course-Persistent offenders 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. However, number of arrests are used in some studies to measure this behavior. Due to similar characteristics and trajectories, this theory can be applied to both females and males.

Antisocial Personality Disorder
Antisocial Personality Disorder is recognized by the DSM-IV. It is a disorder characterized by a severe disregard for the rights of others.

Age and Antisocial Personality Disorder
The number of arrests spike in adolescence, but subsequently decline. 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 the number of people offending as well as the number of total offenses. 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. It is also worth noting that less than 10% of all males warrant an official "antisocial" label.

Some children seem to be more difficult than others. However, there are several more misbehaved children than there are adult criminals. Nevertheless, aggression and antisocial behavior in a child can be a predictor of adult antisocial behavior. Some 'difficult' children exhibit behavioral problems due to neurological dysfunctions. Hertzig 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 or not. These neurologically damaged children have a mean IQ score of 96, only 4 points below the mean of the population.

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 the 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, stealing cars, robbery, rape, and child abuse characterize a life course persistent offender.

Some relevant experiments test heterotypic continuity. These experiments draw conclusions about offenses made early in life and offenses made later in life by the same offender. Generally, the two types of offenses are not the same (i.e. theft early in life and rape later in life). Ryder found that aggression, physical adventurousness, and nonconformity in childhood were related to adult sexual behavior.

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 (ages 6–11) in 1983 consisted of 1,125 subjects. The subjects were assessed using written tests. The parents completed questionnaires on their children from ages 6–11, but during the adolescence and adulthood phase, the parents as well as the subject him/herself completed them. In order to analyze stability, the parent's questionnaire was compared to both the subject's and the parent's questionnaires in the adolescence phase as well as the adult phase. 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.

Biological Risk Factors
Moffitt writes, "Minor physical anomalies, which are thought to be observable markers for hidden anomalies in neural development, have been found at elevated rates among violent offenders and subjects with antisocial personality traits." Neural development in the fetus may also be affected by maternal drug abuse, poor prenatal nutrition, or pre/postnatal exposure to toxic agents. The following biological risk factors have been linked to persistent antisocial behavior throughout the life course. These factors alone do not cause antisocial behavior or life-course-persistent criminal activity.

Brain Injury

 * According to multiple studies, a correlation was found between brain insult suffered during delivery and later antisocial behavior.  Also in acceleration-deceleration traumatic brain injury (TBI), an increase in aggression and antisocial behavior was recorded after the incident.

Brain Activity

 * The right hemisphere is responsible for spatial awareness and orientation. Deficits on this side of the brain can lead to problems in facial and expression recognition. These impairments can not only interfere with early attachment and bonding, but they can lead to adverse parenting due to the child's inappropriate responses.  In one experiment, 868 seven year old boys in Pennsylvania were divided into groups: one group on the life-course persistent offender path, one on the adolescent limited path, and one control group. A Continuous Performance Task test (CPT) was used to test frontal lobe function. Larger neurocognitive impairments were found in the life-course persistent group (LCP) than in the control group. Additionally, positron emission tomography, near-infrared spectroscopy, and magnetoencephalography imaging studies have shown more right hemisphere activation during the CPT. These results from the CPT are consistent with right hemisphere dysfunction in subjects displaying antisocial behavior.


 * Spatial Capabilities


 * In the previous Pennsylvania study, the life-course persistent (LCP) group showed significant impairments on spatial tests compared with the control group. No significant differences were shown between the adolescent limited (AL) group and the control group with respect to spatial IQ.


 * Verbal Capabilities


 * Children exhibiting antisocial behavior early in life, many of whom are the same individuals who continue their trajectory into adulthood, often have difficulties with oral communication. Within the 868 Pennsylvania boys, the LCP group had significantly lower verbal IQ (and regular IQ) scores than the adolescent limited group, and no significant differences were shown between the adolescent limited (AL) group and the control group with respect to verbal IQ.

Minor Physical Anomalies

 * Minor physical anomalies (MPAs) are features such as low-seated ears, furrowed tongue, and adherent ear lobes. They can be caused by genetic or environmental factors, and there seems to be a correlation between them and antisocial behavior.  Evidence supporting the link between minor physical anomalies and antisocial behavior shows that the link only exists when adverse environmental factors are present.

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
Biological	Social Unknown 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 (one of the two). 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

 * The first biological predisposition people normally think of is genetics.  Several experiments use individuals with antisocial parents who have been adopted and raised by other people.  Consistently, however, antisocial behavior prevails in the child despite the deviant, biological parents being absent.   One such experiment used individuals whose biological parents exhibited criminal behavior and who were adopted.  When the adoptive environment was adverse and the genetic predisposition was present, 40% of the adoptees partook in criminal activity compared to only 12.1% with only genetic predispositions.  In one particular study, significant heritability was found for crime, but one subsequent finding was particularly interesting.  Heritability was higher in individuals from high socioeconomic background and those from rural areas.  This is not to say that criminal behavior is more prevalent in wealthier people.  It simply shows that the biological factors are more evident in people who are not predisposed to crime socially.  Similarly, the link between antisocial behavior and biological risk will be stronger in individuals from kindly social backgrounds than individuals from adverse social backgrounds "because the social causes of crime camouflage the biological contribution.  While several studies have been initiated to identify the alleles responsible for aggression, violence, or antisocial behavior, no such discovery has been made thus far.

Minor Physical Anomalies and Environmental Interactions

 * In one study testing 129 boys from age 12 to 21 years with minor physical anomalies (MPAs), the correlation between antisocial behavior and MPAs only existed when the individual suffering from an MPA was exposed to an adverse home environment. This environment was necessary to express the biological predisposition just like an environment is necessary to express certain genes.

Brain Activity and Environmental Interactions

 * A link between prefrontal cortex damage or dysfunction and antisocial behavior, aggression, or violence has been found in many studies. Some frontal lobe lesions have been responsible for impulsivity and disinhibition, which are key characteristics of Antisocial Personality Disorder.  In one such study, a group of murderers were divided into two groups: one with benign social backgrounds and one with malignant social backgrounds.  Using positron emission tomography (PET) scans were used to detect function in different parts of the brain.  Compared to a normal control group, the murderers raised in malignant environments had relatively good prefrontal functioning, but the murderers raised in benign environments had significantly reduced prefrontal functioning.  Most of the reduced functioning was in the right hemisphere.  Functional MRI scans were used in another study with violent offenders and abusive environments.  Four groups were composed of non-violent controls with no history of abuse, violent offenders with a history of abuse, violent offenders with no history of abuse, and non-violent controls with a history of abuse.  The violent offenders who had been abused showed reduced function in the right hemisphere, particularly the right temporal cortex.   According to the authors of this article, this experiment's results imply that good right hemispheric functioning may protect against violence in abused children.

Brain Injury and Environmental Interactions

 * The most well known example of behavioral changes due to a brain injury is Phineas Gage, a gentle, religious man who suffered a severe injury to his prefrontal cortex. While working on a railroad one day, a railroad spike lodged itself in his skull entering under his left cheek bone and exiting on the top of his head.  After the accident, and subsequent removal of the spike, Phineas reportedly became a very violent, aggressive man who drank daily.  There is, however, at least one case of a similar injury in which the social environment after the injury did not result in the same behavioral degredation.  This particular subject was in a high socioeconomic circle, retained a steady job, married later, fathered two healthy children, and never developed antisocial behavior.  While we cannot be absolutely sure that his nurturing social environment was responsible for his consistent behavior before and after the incident, we cannot be sure that it wasn't responsible either.

Adolescent-limited Offenders
Because Moffitt believes that Adolescent Limited Offenders become offenders due to the biological changes of adolescence forced to develop in an environment with antisocial peers, risk factors do not apply to this group. Although one point regarding biological risk factors 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 in the first place.

Etiology
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

Neuroethical Implications
This type of theory leads to several different neuroethical issues. If, in the future, we were able to use brain scans, behavioral data, or another type of screening to identify Life-Course-Persistent offenders in childhood, what type of interventions would be implemented, if any? Would it even be ethical to use brain scans or other screening methods to preemptively test children in the first place? Assuming that the data was so reliable that there was no chance a child tested to be a LCP offender could change course throughout his/her life due to social or environmental factors, what would we do with the children testing positive for LCP offenses? If those positively tested children were placed in a classroom together, away from other children, it is likely that their violence or aggression would simply be exacerbated. Some may argue a more secure environment is necessary to keep these children from developing alongside our 'normal' youth. Do we want to institute policies that "treat troubled children as future criminals?"