THE MOFFIT DEVELOPMENTAL THEORY OF
CRIME
(taken from http://www.apsu.edu/oconnort/crim/crimtheory06.htm)
University of Wisconsin psychology professor Terrie Moffitt's
developmental theory (Moffitt 1993) begins with empirical research indicating
that signs of persistent antisocial behavior can be detected early in life, as
early as the preschool years, and extends to the idea that adolescent deviant
behavior is greatly influenced by the behavior of peer groups even after
parental variables are taken into account. The theory states that two
groups of antisocial youth can be distinguished based on their ages of onset
and trajectories of conduct problems. These two groups differ enough to
require separate causal explanations. It might be helpful to illustrate
some of the distinctions between these two groups in the following table:
|
The Dual Trajectories in the
Origins of Conduct Disorder (CD) |
|
|
"Early Starters" |
"Late Starters" |
|
Life-course-persistent (LCP)
offenders |
Adolescent limited ( |
|
DSM-IV conduct disorder:
childhood-onset type |
DSM-IV conduct disorder:
adolescent-onset type |
|
Minor aggression (bullying,
fighting), lying, hurting animals, biting and hitting by age 4 |
Serious aggression (mugging, forced
sex, use of weapon), stealing, running away, truancy, breaking & entering
|
|
Neurological problems: attention
deficit or hyperactivity |
Little to no problems with peer
rejection; have learned how to get along with others |
|
5-10% of the male juvenile offender
population (2% females) |
Majority of juvenile offender
population; ceases or stops offending around age 18 |
During the teenage years, the two types are
indistinguishable, and no existing paper-and-pencil test for antisocial
tendencies or psychopathy will be able to
discriminate the two types. That's because many of the "late
starters" will "begin" with rather serious delinquency, and many
of the "early starters" will be just "escalating" into
serious delinquent behavior at about the same time. Because many of the
"late starters" may only be engaging in symbolic adolescent rebellion
(perhaps because something is forbidden), have usually maintained empathy and
avoided peer rejection, and are smart enough to see the rewards in more
socially approved behavior, they usually "dropout" or desist from any
pathway toward crime. Not so with the "early starters" (the most
frequently studied group) who may only be precociously escalating into
serious offenses as a way of expanding the versatility of their antisocial ways
across all kinds of conditions and situations. In fact, a trajectory
toward versatility might be apparent with early starters at a very young
age. The research indicates that increasingly higher levels of early
conduct problems are associated with increasingly higher levels of late conduct
problems, and Tremblay's (2003) research also shows that the best predictors of
early starters are: having a target (sibling); parental separation before
birth; and low income.
Although the number of early starters in the population of interest may only amount to
5-10% of the total, such children and adolescents usually account for more than
50% of referrals to authorities and mental health services. Their
behavior is disruptive not only to authorities, but to their peers, and for
this reason, they experience significant amounts of
peer rejection. Not only does this limit their chances for "getting
ahead" on the basis of normal, lasting relationships, but their poor
interpersonal or social skills are combined with three other prominent
features, as follows, and discussed in separate paragraphs below:
·
hyperactive-impulsive-attention problems
·
conduct problems
·
below-average intelligence or low-IQ
The first feature -- attention deficit/hyperactivity
disorder (ADHD) -- refers to a complex set of behaviors characterized by three
central features: (1) excessive motor activity (cannot sit still, fidgets, runs
about, is talkative and noisy); (2) impulsivity (acts before thinking, shifts
quickly from one activity to another, interrupts others, does not consider
consequences of behavior); and (3) inattention (does not seem to listen, is
easily distracted, loses things necessary for essential tasks). ADHS
should not be confused with ODD (oppositional defiant disorder) which has the
following cluster of symptoms: (1) arguing with adults; (2) refusing adults'
requests; (3) deliberately trying to annoy others; (4) blaming others for
mistakes; and (5) being spiteful or vindictive (Kosson
et. al. 2002). ADHS afflicts as many as 20% of American school-age
children, boys more than girls (by a ratio of 9:1), and blacks more than other
ethnic groups, for debatable reasons ranging from speculations about genetic
predisposition to the possibility of exposure to hazardous toxins in black
communities. Many people afflicted with ADHD never "outgrow"
it, and theories about the continuity of learning disabilities into adulthood
are also controversial. The most common treatment is methylphenidate,
also known as Ritalin, but it has mixed effects, and a successful treatment
regimen for ADHD has yet to be found.
Conduct problems refer to the variety of symptoms
found in the diagnostic category of Conduct Disorder (CD), and among delinquent
youth, these are usually "co-occurring psychopathologies" that exist
between one or more of these symptoms and ADHD symptoms. In fact, Bartol & Bartol (2004) report
on research indicating that as many as 50% of disruptive children exhibit
having the symptoms of CD half the time and the symptoms of ADHD the other half
of the time. According to the APA, the central feature of CD is a
repetitive and persistent pattern of behavior that violates the rights of
others, and early-onset CD generally begins before age 10. Symptoms of CD
include stealing, fire setting, running away, truancy, destroying property,
fighting, telling lies on a frequent basis, and being cruel to animals and
people. It is the consensus of scholars that conduct disorder (CD) is
roughly the juvenile equivalent of adult antisocial personality disorder.
Conduct disorder typically gets worse as the child gets older, and it is often
misdiagnosed as a learning disability (because there are frequent problems with
school assignments) whereas someone with a "true" learning disability
may not be conduct-disordered. CD afflicts about 16% of the male
population and about 9% of the female population.
Below-average intelligence or low IQ refers to a lower
cognitive ability and slow language development that, at times, is called by
other names, such as "neuropsychological dysfunction" or impairment
of "executive functioning." Low IQ is strongly associated with
an early age of onset for Conduct Disorder (CD) and has a relationship to
delinquency which holds even when socioeconomic status (SES) is controlled
for. An 8 to 10 point difference is usually found on any standard
intelligence test comparing delinquents with nondelinquents.
There are some interesting findings regarding ethnic differences in how low-IQ
is related to delinquency, as low-IQ whites tend to follow a
"susceptibility" pathway to the typical personality disorders, and
low-IQ minorities (blacks, Latinos, and Asians) tend to follow a "school
failure" (being held back) pathway to lower "emotional
intelligence" which results in decreased empathy and violent misreading of
emotional cues from others.