Adversité socioéconomique, fréquentation d’un service d’éducation préscolaire, et développement de l’enfant : investigations expérimentales et longitudinales populationnelles

Background: Early life adversity is associated with life-long consequences on children's physical and mental health. Early childhood education and care (ECEC) attendance has been proposed as a solution to promote the development of children from vulnerable families and thus diminishing the negative consequences associated with their early exposure to adversity. ECEC is widely available to the general population and used by working parents for their preschool children. However, because of social selection processes, vulnerable children are less likely to attend ECEC than their more advantaged counterparts. In addition, although ECEC is generally a cognitively and socially stimulating environment, there are significant variations in the quality of these services. Moreover, ECEC are conducive to situations that can be a stressful and associated with the expression of disruptive behaviors. Objectives: The main objective of this thesis is to examine the associations between exposure to socioeconomic adversity, ECEC attendance, and children development while using a life-course approach and paying particular attention to social selection processes into ECEC. This thesis is divided into four papers. The first two articles examine the impact of a social skills training program implemented in ECEC facilities of low-income neighborhoods on children's levels of disruptive behaviour and stress. In addition, these papers investigate the moderating role of family socioeconomic adversity on the impact of the program. The third paper examines the moderating effect of ECEC attendance on the association between exposure to early life adversity and disruptive behaviours during adolescence via children's cognitive abilities. The fourth paper investigates whether ECEC attendance is associated with higher rates of compulsory school graduation, and whether this association is stronger among children of mothers with lower levels of education. Finally, this paper provides a benefit-cost ratio analysis to assess whether subsidising ECEC is an economically viable option. Methods: The first two papers used data from the Brindami cluster randomized trial in which 19 ECEC facilities (n = 362 children) from low-income neighborhoods were randomized to the experimental condition: receiving a social skills training program, or to the waiting list control condition. Levels of disruptive behaviours and stress levels assess with salivary cortisol were measured at pre- and post-intervention. Multi-level analysis with repeated measures were used to study the impact of the program. Social selection effects were considered through the application of strict ECEC selection criteria. For the third and fourth thesis paper, data were drawn from the Avon Longitudinal Study of Parents and Children (ALSPAC) where 14,451 families were followed from 1991-2020. ECEC attendance and exposure to early life adversity were measured by questionnaires during the child's first four years of life. Children’s cognitive abilities were measured during a laboratory visit when the child was eight years old. Children’s disruptive behaviours were assessed by the mother on three occasions during adolescence using a validated questionnaire. Information on compulsory school graduation was obtained via a linkage between the United Kingdom National Pupil Database and the children from the ALSPAC study. Moderated mediation and multinomial regression analyses were used. Social selection effects were controlled through the use of propensity scores. Results: The first two papers showed that the implementation of a social skills training program was associated with 1) a decrease in disruptive behaviours, but only among girls, and 2) with more normative diurnal cortisol secretion patterns, particularly for children of economically disadvantaged families. The third paper suggests that for children exposed to early life adversity, ECEC attendance is associated with a decrease in disruptive behaviours during adolescence via an increase in children’s cognitive abilities. Finally, the fourth paper presents a significant association between ECEC attendance and school graduation for children of mothers with lower levels of education and suggests that subsidising ECEC for these children is a cost-effective measure. Implications: This thesis highlights the importance of ECEC attendance for children exposed to socioeconomic adversity. To achieve ECEC social equalizing effect, stakeholders need to consider social selection processes into ECEC in the elaboration of their policy.

Keyphrases: Stress, Socioeconomic adversity, Early childhood education and care, Social skills training, Cognitive skills, Disruptive behaviors, High school graduation, Life course approach, Social selection, Iniquities, Social determinants of health