1. Objectifs

Intentions :
«[T]he primary aim of the present study [is] to elucidate the role of genetic, shared and non-shared environmental factors in explaining different developmental trajectories of alcohol use during adolescence.» (p. 1205)

2. Méthode

Échantillon/Matériau :
«The 421 twin pairs in the study […] were part of a population-based sample of 662 twin pairs from the greater Montréal area recruited at birth between November 1995 and July 1998.» (p. 1205)

Instruments :
Questionnaire

Type de traitement des données :
Analyse statistique

3. Résumé

«This finding highlights the importance of shared environmental factors in affecting the initiation of alcohol use throughout adolescence. Parental attitudes toward their children’s alcohol use, parental supervision, family religion […], and even influences from broader contexts such as neighborhood and community norms on alcohol use and regulations […] possibly play a major role in delaying the initiation of alcohol use. […] This finding [also] suggests that, besides genetic predisposition, the environmental factors that lead adolescents to follow the normative increasing trajectory are primarily person-specific experiences that distinguish family members from each other. In contrast, the relatively more problematic early-onset trajectory was under moderate shared environmental influences. Similar shared environmental factors that influence membership in the low trajectory (e.g., parental attitudes toward alcohol use, family religion, parental alcohol use) […] possibly also explain why adolescents follow an early-onset trajectory. Significant shared environmental influences were found in regard to the low and early-onset trajectories, but not in regard to the normative increasing trajectory. This suggests that shared environmental factors play a major role in affecting the onset of alcohol use, either delaying (as in the low trajectory) or promoting (as in the early-onset trajectory) its initiation.» (p. 1209-1210)