MONTRÉAL, June 22, 2016 - Years of research have shown that impulsivity in childhood is among the individual vulnerabilities leading to substance abuse, delinquency, as well as aggressive and antisocial behavior in adolescence and adulthood. Yet researchers from the CHU Sainte-Justine Mother-child Research Hospital and University of Montreal have discovered a reversal of this trend for those children when raised in a less coercive environment. "According to our results, labelling impulsive children as "vulnerable" should be reconsidered. Indeed, those who were raised in less coercive families at the age of 6 actually drank less alcohol than their less impulsive peers at the age of 15. Their supposed vulnerability actually turned into an advantage," says Charlie Rioux, PhD candidate in psychology and first author of the paper published in Development and Psychopathology.
Acting rapidly and without thinking are typical signs of child impulsivity. According to the researchers, this trait, traditionally viewed as negative, could turn into an advantage when combined with a caring family environment. "A Swedish metaphor illustrates this differential susceptibility to the environment," explains Charlie Rioux. "Many children exposed to challenging environments do quite well. They are said to be resilient, and are referred to as "dandelion children", since they are well adjusted even when exposed to harsh conditions. Children more susceptible to their environment, like impulsive ones, are referred to as "orchid children." For if the orchid fades in harsh conditions, it also thrives when given proper care and attention. We observed that when they are raised in a supportive environment, "orchid children" not only do well in adolescence, but can even outperform their less susceptible peers in many respects." The researchers came to this interesting finding by looking at how these children develop in both adverse and non-harmful environments.
To achieve these results, the researchers studied 209 youth born between 1996 and 1997 in urban areas of the Province of Quebec, in Canada. When these youth were 6 years old, their mothers completed questionnaires on their child's impulsivity levels and the coercive practices they used as a parent, including screaming, shaking or hitting. Then at the age of 15, the adolescents reported the frequency of their alcohol use. The results of the study show that when maternal coercive practices were more frequent at 6 years, higher impulsivity at this age was associated with more frequent alcohol use at the age of 15. In contrast, highly impulsive 6-years-olds exposed to infrequent maternal coercive practices had a lower frequency of alcohol use compared to less impulsive children. "These results are particularly interesting because impulsivity is often considered a risk factor for alcohol use. However, our results show that more impulsive children may drink less alcohol than kids who are less impulsive when exposed to low maternal coercive practices," said Jean Séguin, PhD, professor of psychiatry at the University of Montreal, researcher at CHU Sainte-Justine and co-director of Rioux's doctoral thesis.
The researchers also conducted a literature review that points in the same direction. Their review identified 14 studies investigating the role of family environment and child and adolescent temperament in the development of adolescent "externalizing problems". These notably include delinquency, antisocial behaviors, attentional problems and substance use. In line with their own observations, this review, published in Developmental Review, demonstrates that susceptibility in childhood - characterized by such traits as impulsivity, disinhibition, or low fear or shyness - is associated with higher levels of externalizing problems in adolescence when children were exposed to adverse environments, but lower levels of externalizing problems when they were raised in suitable home environments. However, having an appropriate home environment during adolescence does not seem to convey any additional benefit to susceptible adolescents. These studies considered several family factors, including maternal and paternal parenting, parent-child relationship and marital conflict.
"Although many factors come into play in shaping the future behaviour of children, our findings tend to suggest that special attention to the needs of impulsive children or children susceptible to their environment at an early age may help them realize their full potential," says Charlie Rioux. "To demonstrate this, our results will need to be replicated in clinical studies also designed to test the differential susceptibility model, this time not only assessing the impact of more or less coercive parenting methods, but also the impact of intervention programs targeting parenting practices."
About the study
The articles "Differential susceptibility to environmental influences: Interactions between child temperament and parenting in adolescent alcohol use" and "The interaction between temperament and the family environment in adolescent substance use and externalizing behaviors: Support for diathesis-stress or differential susceptibility?" were published respectively in Development and Psychopathology and Developmental Review. Charlie Rioux is the first author. She is continuing her work under the supervision of University of Montreal Professors Jean R. Séguin, of the Psychiatry Department, and Natalie Castellanos-Ryan, of the School of Psychoeducation, with the collaboration of Sophie Parent, also of the School of Psychoeducation. All are members of the Research Unit on Children's Psychosocial Maladjustment (GRIP) of the University of Montreal and the CHU Sainte-Justine. The studies were funded by the Canadian Institutes for Health Research (CIHR), the Social Sciences and Humanities Research Council of Canada, the Fonds de recherche du Québec - Santé (FRQS), the Fonds de recherche du Québec - Nature et technologies (FRQNT), the Fonds de recherche du Québec - Société et culture (FRQSC), as well as the Institut de la statistique du Québec, and its partners. Charlie Rioux holds scholarships from the IRSC, the FRQS, and the University of Montreal.
About the CHU Sainte-Justine Research Center
CHU Sainte-Justine Research Center is a leading mother-child research institution affiliated with Université de Montréal. It brings together more than 200 research investigators, including over 90 clinician-scientists, as well as 385 graduate and postgraduate students focused on finding innovative prevention means, faster and less invasive treatments, as well as personalized approaches to medicine. The Center is part of CHU Sainte-Justine, which is the largest mother-child center in Canada and second pediatric center in North America. More on research.chusj.org
About the University of Montreal
Université de Montréal and its two affiliated schools, École Polytechnique (engineering) and HEC Montréal (business) are amongst the world's top 100 universities, according to international rankings. Founded in 1878, the campus today has over 66,000 students and 2,600 professors, making Université de Montréal the second largest university in Canada. Its students are drawn to the university by its deep roots in cosmopolitan Montreal and in consideration of its tenacious dedication to its international mission. The University of Montreal is officially known as Université de Montréal.