THE MONTREAL LONGITUDINAL-
Prepared by Patricia Begin
Political and Social Affairs Division
3 March 1995
TABLE OF CONTENTS
THE MONTREAL LONGITUDINAL-EXPERIMENTAL STUDY
Canadians are demanding more value for their investment in crime-fighting. Traditional
reactions to crime police, courts, corrections and legal aid are costly.
Government spending on these justice system services reached $9.57 billion in 1992-93,
representing a 34% increase over 1988-89 spending. Yet personal and public security
concerns continue to be priority issues for many Canadians.
A consensus is emerging among criminal
justice professionals, service providers, social commentators and segments of the public
that the conventional crime control model, which involves identifying and punishing those
who breach our laws, has largely failed to reduce victimization and promote safety in our
communities. In addition to resources to react to crime, they call for investments in
crime prevention initiatives that focus on the underlying causes of crime and
There is mounting evidence that children
exhibiting high levels of anti-social behaviours early in life, particularly those who are
from economically disadvantaged, dysfunctional families and who experience academic and
social problems at school, are at risk of developing into persistent young offenders and
adult offenders. Observation and clinical assessments can identify children who are at
risk of posing threats to community safety, threats that are likely to become
progressively more serious as the youth proceed from adolescence to adulthood. Young
people with serious social and behavioural difficulties, left untreated, become problems
for the criminal justice system. By the time they are identified as a high risk in the
community and incarcerated, it is often too late for them to profit from treatment aimed
at instilling prosocial attitudes and behaviours. The prognosis for these
"at-risk" young people highlights the need for preventive interventions.
Researchers have examined the relationship
between poor parenting skills and children's poor social skills, and postulated that they
are causally related to the development of delinquency. The effects of parent skills
training and children's social skills training on reducing disruptive, aggressive
behaviour and preventing delinquent behaviour have been evaluated. When implemented
separately, these preventive measures have yielded uneven results. To assess the impact of
both parent skills training and children's prosocial skills training, and to
examine the social development of disruptive boys during the early school years, a
longitudinal-experimental study of "at-risk" boys was conducted by researchers
from the University of Montreal. The study is discussed by R.E. Tremblay, et al.,
in "Parent and Child Training to Prevent Early Onset of Delinquency: The Montreal
Longitudinal Study," in J. McCord and R.E. Tremblay (eds.), Preventing Antisocial
Behaviour: Interventions from Birth through Adolescence, Guilford Press, New York,
1992 (p. 117-138).
AND RESEARCH METHODOLOGY
In spring 1984, the study was begun in
Montreal schools located in areas largely inhabited by families of low socio-economic
status. Kindergarten teachers were asked to rate the behaviour of each of the boys in
their classes at the end of the school year. Ratings were completed by 87% of the
kindergarten teachers and, in all, boys from 53 schools were selected for the longitudinal
study. To control for the influence of culture on behaviour, boys were included as study
subjects if their biological parents had been born in Canada and if the parents' mother
tongue was French. To ensure that only those from families with low socio-economic status
were included, boys whose parents had attained more than 14 years of schooling were not
selected for the study.
The boys identified by their kindergarten
teachers as being at-risk (i.e. disruptive, hyperactive, aggressive) were randomly
assigned to three groups by the University of Montreal researchers: the treatment group,
created for the experimental study of prevention; the observation group, created
for the longitudinal observational study of the social interactions of disruptive boys;
and, the no-treatment, no-contact control group, for evaluating the effects of the
experimental study and of the longitudinal follow-up.
Parenting training programs were delivered
by professionals working with individual families over a two-year period. The treatment
for parents emphasized close supervision of children's behaviour, positive reinforcement
of prosocial behaviour, consistent, non-abusive discipline strategies, and management of
Professionals provided social skills
training in the school to small groups which included disruptive boys and prosocial peers.
On average, the boys received treatment from the age of 7 to the age of 9. Treatment
focused on social skills to promote positive interaction with teachers, parents and peers,
problem-solving and self-regulation skills. Work was carried out with the teachers of the
treated boys as well.
Post-treatment, the behaviour of the boys
was assessed annually (from age 9 to age 12) by teachers, peers, mothers and the boys
themselves. For all of the boys in the three groups, ratings were obtained on a number of
indicators: educational achievement, fighting behaviour, overall school behaviour and
performance, delinquent behaviour, mothers' perception of antisocial behaviour and the
nature of parent-child relationships. This made it possible to assess the impact of
intensive treatment on antisocial, disruptive behaviour.
The objectives of the parenting skills and
children's social skills treatment were to reduce disruptive behaviour identified in
kindergarten boys and thereby move them off the trajectory leading from early aggressive,
antisocial behaviour to later aggressive, delinquent behaviour. The results from the three
years of follow-up of this longitudinal-experimental research are encouraging and have
By the end of primary school, the
behaviour of the disruptive boys in the untreated group confirmed previous research
findings that physical aggressiveness and academic problems, are predictors of delinquency
that are identifiable early on in a child's development. The research also confirmed that
social intervention can positively affect the social development of disruptive boys.
Compared with the untreated boys, the boys who received the intensive multi-faceted
treatment exhibited less aggression in school, performed well academically more often,
experienced fewer difficulties in adjusting to school, and reported committing fewer
delinquent acts up to three years after the end of treatment.
With respect to teacher-rated fighting,
the boys in the control and observational groups had a significantly higher fighting score
than those in the treated group. Untreated boys were twice as likely to be rated as having
serious school behaviour and school performance problems as the boys in the treatment
group (44% vs. 22%). A smaller proportion of the treated, than of the untreated, reported
having committed delinquent acts involving trespassing (40% vs. 62%), stealing items worth
less than $10 (19% vs. 45%), stealing items worth more than $10 (7% vs. 20%), and stealing
bicycles (5% vs. 19%). No significant differences were found between the treated and
untreated boys in terms of hyperactivity, prosociality and vandalism.
The researchers note that, at present, the
long-term effects of the treatment administered are unknown. It is their intention to
continue to track the development of the boys as they grow older in order to evaluate the
durability of proactive intervention in preventing serious juvenile offending.
Delivering intensive social development
and crime prevention programs (such as those in the Montreal longitudinal study) to
children who are early identified to be anti-social (i.e., troubled, aggressive and
hyperactive) is demonstrably more effective than warehousing them as adolescents in
correctional institutions. According to many service providers in the youth justice
system, custodial sentences fail to address the unmet developmental needs of chronic
offenders, to teach young offenders to assume personal responsibility for their behaviour
or to contribute to public safety. This view is buttressed by the fact that slightly less
than half (46%) of the cases referred to youth court in 1990-91 involved recidivists.
Some early treatment models in the United
States have, over the long term, been shown to decrease rates of juvenile crime and reduce
criminal justice and social welfare costs. The Perry Preschool Project, an enriched
pre-school program directed at multi-problem children and their families living in
disadvantaged conditions, is one such model. An evaluation of the program found that,
compared with a matched control group, the 3 to 6 year olds who had participated in the
intervention were more likely to finish high school, attend post-secondary school, and be
employed. There was also less teenage pregnancy, drug abuse and dependence on welfare
among the participants and fewer had an arrest and conviction record. A cost-benefit
analysis found that for each $1 invested in the preschool program there was a $5 return.
Crime prevention advocates argue
persuasively that our historical and current emphasis on police, courts and corrections,
to the exclusion of preventive strategies, has not brought about a reduction in levels of
victimization, fear and crime. It is recognized that proactive measures such as the Perry
Preschool Project, while not a cure for crime, may be more effective than punishment in
delivering long-term protection to society.