L'établissement des jeunes couples : réseaux et soutien social

La présente thèse s'inscrit dans les pratiques de soutien. Elle s'appuie sur le concept de réseau. La recherche a été effectuée à partir d'entrevues et de questionnaires obtenus auprès de 20 couples avec enfants, vivant à Québec et à Lévis, qui ont entrepris de réaliser leur établissement. Deux types de liens y sont explorés, soit les liens forts ou tissés serrés et les liens faibles ou mi-serrés, ceux-ci étant constitués de non intimes, par exemple, des collègues de travail, des camarades d'études, des groupes associatifs et volontaires, etc. L'entrée dans la modernité a scindé les liens sociaux en deux composantes, soit les liens forts représentés par la parenté immédiate et les amis, ainsi que les liens faibles, soit diverses connaissances, formelles et informelles. Malgré leur nombre et leur utilité, les liens faibles sont souvent négligés dans les recherches sur le soutien. Il s'agissait, dans cette étude, de savoir si les liens de parenté étaient encore vivaces et ensuite, de déterminer dans quelle proportion le soutien pouvait être obtenu des réseaux à liens faibles ou mi-serrés, lorsque l'aide des proches n'était pas disponible. Il nous importait également de connaître la variété des significations que les répondants et les répondantes attribuaient à cette assistance, selon la notion des représentations sociales. Par ailleurs, cette thèse confirme la compétence que détiennent les sujets pour contourner les contraintes - se rapportant, ici, à l'obtention d'un soutien - tel que défini dans la pensée structuraliste constructiviste. Les liens de parenté n'ont pas perdu leur vivacité, bien au contraire. Nous avons relevé leur prégnance dans la présente étude de même que le climat d'affectivité qui régnait dans les familles rencontrées. Nos informateurs et informatrices préfèrent l'assistance des parents qui dispensent une aide autant matérielle que morale. Cependant, cette assistance est réduite lorsque les couples habitent loin de la parenté, comme c'est le cas dans notre étude pour près de la moitié des répondants(es). Notre enquête démontre que les familles reçoivent une moyenne d'assistance plus élevée de la part de leurs réseaux à liens faibles que de leurs réseaux à liens forts. Cette aide vient suppléer le déficit d'assistance des proches. La majorité des couples adhérent à des réseaux à liens faibles informels et à des groupes formels répondant à diverses vocations, en partant des organismes communautaires jusqu'aux associations sportives, culturelles ou récréatives.\ud ______________________________________________________________________________ \ud MOTS-CLÉS DE L’AUTEUR : réseaux, soutien, assistance, liens forts, liens tissés serrés, liens faibles, liens mi-serrés, connaissances, familles, couples, établissement

Longitudinal links between gambling participation and academic performance in youth : a test of four models

Gambling participation and low academic performance are related during adolescence, but the causal mechanisms underlying this link are unclear. It is possible that gambling participation impairs academic performance. Alternatively, the link between gambling participation and low academic performance could be explained by common underlying risk factors such as impulsivity and socio-family adversity. It could also be explained by other current correlated problem behaviors such as substance use. The goal of the present study was to examine whether concurrent and longitudinal links between gambling participation and low academic performance exist from age 14 to age 17 years, net of common antecedent factors and current substance use. A convenience sample of 766 adolescents (50.6% males) from a longitudinal twin sample participated in the study. Analyses revealed significant, albeit modest, concurrent links at both ages between gambling participation and academic performance. There was also a longitudinal link between gambling participation at age 14 and academic performance at age 17, which persisted after controlling for age 12 impulsivity and socio-family adversity as well as current substance use. Gambling participation predicts a decrease in academic performance during adolescence, net of concurrent and antecedent personal and familial risk factors

Personal and familial predictors of peer victimization trajectories from primary to secondary school

Using a sample of 767 children (403 girls, 364 boys), this study aimed to 1) identify groups with distinct trajectories of peer victimization over a six-year period from primary school through the transition to secondary school, and 2) examine the associated personal (i.e., aggression or internalizing problems) and familial (family status, SES, the parent-child relationship) predictors. Peer victimization was assessed via self-reports from grades 4 through 9 (ages 10 through 15 years), aggression and internalizing problems were assessed in grade 4 via peer nominations, and the parent-child relationship was assessed in grade 7 (i.e., right after the transition to secondary school) via parent-reports. Growth Mixture modeling revealed one group (62%) who experienced little victimization in primary school and even less in secondary school, another group (31%) who was victimized in primary but not or much less in secondary school, and a third group (7%) who was chronically victimized across in both school contexts. Boys were more likely than girls to follow any elevated victimization trajectory. Chronic victimization across primary and secondary school was predicted by non-intact family status and a combination of both internalizing problems and aggression compared to non-victimized youth. In contrast, transitory victimization during primary but not in secondary school was predicted by aggression, but not internalizing problems. Support as well as conflict in the parent-child relationship also showed significant, albeit distinct associations with the different peer victimization trajectories

The dark side of friends : a genetically informed study of victimization within early adolescents’ friendships

Using a genetically informed twin design, this study examined (a) whether, in line with gene–environment correlation (rGE), a genetic disposition for anxiety puts children at risk of being victimized by a close friend or by other peers, and (b) whether, in line with gene–environment interaction (GxE), victimization by a close friend or by other peers moderates the expression of a genetic disposition for anxiety. Participants were 268 monozygotic and dizygotic twin pairs (MZ males = 71, MZ females = 80, DZ males = 56, DZ females = 61; 87% of European descent) assessed via questionnaires in Grade 8 (M age = 14.06 years, SD = 3.60). Participants reported about their victimization by a close friend and by other peers and their anxiety level. Victimization by a close friend and victimization by other peers were uncorrelated. In line with rGE, genetic factors related to anxiety predicted victimization by other peers, whereas victimization by a close friend was not predicted by heritable characteristics. Moreover, in line with a suppression process of GxE, victimization by other peers reduced the role of genetic factors in explaining interindividual differences in anxiety. In contrast, in line with a diathesis-stress process of GxE, victimization by a close friend fostered the expression of a genetic disposition for anxiety. Victimization by a close friend seems to happen to adolescents regardless of their personal, heritable characteristics. If it does occur, however, it is a source of distress mostly for youth with a genetic vulnerability for anxiety

Gene-environment correlation linking aggression and peer victimization : do classroom behavioral norms matter?

Using a genetically informed design based on 197 Monozygotic and Dizygotic twin pairs assessed in grade 4, this study examined 1) whether, in line with a gene-environment correlation (rGE), a genetic disposition for physical aggression or relational aggression puts children at risk of being victimized by their classmates, and 2) whether this rGE is moderated by classroom injunctive norm salience in regard to physical or relational aggression. Physical aggression and relational aggression, as well as injunctive classroom norm salience in regard to these behaviors, were measured via peer nominations. Peer victimization was measured via self-reports. Multi-Level Mixed modeling revealed that children with a genetic disposition for either aggressive behavior are at higher risk of being victimized by their peers only when classroom norms are unfavourable toward such behaviors. However, when classroom injunctive norms favor aggressive behaviors, a genetic disposition for physical or relational aggression may actually protect children against peer victimization. These results lend further support to the notion that bullying interventions must include the larger peer context instead of a sole focus on victims and bullies

Friendship experiences and anxiety among children : a genetically informed study

This study examined (a) whether, in line with a gene-environment correlation (rGE), a genetic disposition for anxiety puts children at risk of having anxious friends or having no reciprocal friends; (b) to what extent these friendship experiences are related to anxiety symptoms, when controlling for sex and genetic disposition for this trait; and (c) the additive and interactive predictive links of the reciprocal best friend's anxiety symptoms and of friendship quality with children's anxiety symptoms. Using a genetically informed design based on 521 monozygotic and ic twins (264 girls; 87% of European descent) assessed in Grade 4 (M age = 10.04 years, SD = .26), anxiety symptoms and perceived friendship quality were measured with self-report questionnaires. Results indicated that, in line with rGE, children with a strong genetic disposition for anxiety were more likely to have anxious friends than nonanxious friends. Moreover, controlling for their genetic risk for anxiety, children with anxious friends showed higher levels of anxiety symptoms than children with nonanxious friends but did not differ from those without reciprocal friends. Additional analyses suggested a possible contagion of anxiety symptoms between reciprocal best friends when perceived negative features of friendship were high. These results underline the importance of teaching strategies such as problem solving that enhance friendship quality to limit the potential social contagion of anxiety symptoms

The expression of genetic risk for aggressive and non-aggressive antisocial behavior is moderated by peer group

Numerous studies have shown that aggressive and non-aggressive antisocial behaviors are important precursors of later adjustment problems. There is also strong empirical evidence that both types of antisocial behavior are partially influenced by genetic factors. However, despite its important theoretical and practical implications, no study has examined the question whether environmental factors differentially moderate the expression of genetic influences on the two types of antisocial behavior. Using a genetically informed design based on 266 monozygotic and dizygotic twin pairs, this study examined whether the expression of genetic risk for aggressive and non-aggressive antisocial behavior varies depending on the peer group’s injunctive norms (i.e., the degree of acceptability) of each type of antisocial behavior. Self-reported aggressive and non-aggressive antisocial behavior and classroom-based sociometric nominations were collected when participants were 10 years old. Multivariate genetic analyses revealed some common genetic factors influencing both types of antisocial behavior (i.e., general antisocial behavior) as well as genetic influences specific to non-aggressive antisocial behavior. However, genetic influences on general antisocial behavior, as well as specific genetic influences on non-aggressive antisocial behavior, vary depending on the injunctive classroom norms regarding these behaviors. These findings speak to the power of peer group norms in shaping aggressive and non-aggressive antisocial behavior. They also contribute further to understanding the distinctive development of both types of antisocial behavior. Finally, they may have important implications for prevention purposes

Links between friends' physical aggression and adolescents' physical aggression : what happens if gene-environment correlations are controlled?

Exposure to deviant friends has been found to be a powerful source of influence on children’s and adolescents’ aggressive behavior. However, the contribution of deviant friends may have been overestimated because of a possible non-accounted gene-environment correlation (rGE). In this study, we used a cross-lagged design to test whether friends’ physical aggression at age 10 predicts an increase in participants’ physical aggression from age 10 to age 13 years. Participants were 201 pairs of monozygotic twins who are part of the Quebec Longitudinal Twin Study. We performed two sets of analyses. In the first set of analyses, using twins as singletons, we found that teacher-rated friends’ physical aggression predicted an increase in each twin’s self-reported physical aggression from age 10 to age 13, above and beyond auto-regressive and concurrent links. Second, we used within-pair differences in regard to friends’ physical aggression to predict an increase in within-pair differences in physical aggression, thus accounting for family-wide influences, including a likely rGE at age 10. No significant association was found, however. These results suggest that part of the influence attributed to friends in past studies may have been due to common underlying genetic effects on both physical aggression and association with physically aggressive friend

Environmental influence of problematic social relationships on adolescents' daily cortisol secretion : a monozygotic twin-difference study

BACKGROUND: This study investigated the potential environmental effects of peer victimization and the quality of relationships with parents and friends on diurnal cortisol secretion in mid-adolescence. METHOD: This study used the monozygotic (MZ) twin-difference design to control for genetic effects and thus estimate the unique environmental influences on diurnal cortisol. Participants were 136 MZ twin pairs (74 female pairs) for whom cortisol was assessed four times per day over four collection days grouped in a 2-week period in grade 8 (mean age = 14.07 years). Participants also provided self-reports of peer victimization from grade 4 to grade 8 and of the relationship quality with the mother, father and best friend in grade 8. RESULTS: The expected pattern of diurnal cortisol secretion was observed, with high levels at awakening followed by an increase 30 min later and a progressive decrease subsequently. Controlling for a host of confounders, only within-twin pair differences in peer victimization and a problematic relationship with the mother were significantly linked to twin differences in diurnal cortisol secretion. Specifically, whereas a more problematic mother-child relationship was associated with morning cortisol secretion, peer victimization was linked to cortisol secretion later in the day (diurnal slope). CONCLUSIONS: Controlling for genetic influences and other confounders, stressful relationships with peers and the mother exert unique and time-specific environmental influences on the pattern of diurnal cortisol secretion in mid-adolescence

Does cortisol moderate the environmental association between peer victimization and depression symptoms? a genetically informed twin study

Many youths who are victimized by peers suffer from depression symptoms. However, not all bullying victims become depressed and individuals’ biological sensitivity may play an important moderating role in this regard. In line with this notion, peer victimization has been associated with increased depressive symptoms in youth with higher basal cortisol secretion. It is unclear, however, whether this moderating effect of cortisol really concerns the environmental effect of peer victimization on depression. Indeed, genetic factors can also influence individuals’ environmental experiences, including peer victimization, and part of these genetic factors may be those associated with depression. Using a genetically informed design based on 159 monozygotic and 120 dizygotic twin pairs (52% girls) assessed at age 14 years, this study examined whether cortisol secretion moderates the environmental or the genetic association between peer victimization and depression symptoms. Salivary cortisol at awakening was obtained with buccal swabs during four school week days. Peer victimization and depression were assessed via self-reports. Cholesky modeling revealed that peer victimization was associated with depression symptoms via both genetic and environmental pathways. Moreover, the environmental association between peer victimization and depression symptoms steadily increased with increasing levels of morning cortisol. The genetic association between peer victimization and depression symptoms also varied, albeit less, as a function of individuals’ cortisol secretion. These findings support the hypothesis that peer victimization increases internalizing psychopathology mainly in youth with heightened biological reactivity to environmental conditions