Background/objectives: Early childhood is marked by rapid physical and cognitive development, underscoring the critical influence of parental choices in shaping habits, pastimes, and traditions. The World Health Organization highlights habits of physical activity, sleep, and screen use as modulators of healthy development and well-being in young children. As a first, this birth cohort study investigates the relationship between movement behaviors in toddlerhood and subsequent sport participation during middle childhood. Methods: Participants are 930 boys and 926 girls from the Quebec Longitudinal Study of Child Development. Using a population-based analytical approach, we examined the relationship between parent-reported active leisure, sleep, and sedentary screen time at age 2 years and trajectory of sport participation between ages 6 and 10 years using sex-stratified linear regressions that account for a range of pre-existing individual and family confounding factors. Results: Many child and family characteristics predicted early childhood movement behaviors, distinctly for boys and girls. Moreover, parental regulation of screen time during early childhood significantly influenced their decisions to enroll and encourage sport participation in sons during school age. Specifically, boys who spent more than 1 h/day on screens had 10% fewer chances of consistently participating in sport throughout middle childhood, even after accounting for adherence to other lifestyle habits. Conclusions: Our findings suggest that parental values regarding early childhood screen exposure are an effective potential target for intervention fostering healthy and active development. Future research should focus on parent and child motivations for sport involvement in the long-term.

Cross-sectional research suggests associations between enrichment and cognitive skills in toddlerhood. There are no prospectively designed longitudinal studies that investigate the link between early home literacy activities and subsequent mechanisms that explain the putative cognitive benefits. This study tests long-term associations between toddler literacy enrichment and later student engagement across key academic transitions, from kindergarten to the end of high school. Using the Quebec Longitudinal Study of Child Development (QLSCD) population-based birth cohort data, we examined whether parent-reported experiences of shared reading, looking at picture books or illustrated stories, and pretend writing at age 2 years predict later teacher- and self-reported student engagement at ages 6, 12, and 17 years. The results from multiple regression models, stratified by sex and adjusted for pre-existing and concurrent child and family characteristics, revealed significant associations between early literacy enrichment and later engagement. For boys and girls, literacy enrichment in toddlerhood predicted increases in classroom engagement from kindergarten to the end of high school. These findings highlight the lasting influence of early literacy exposure on subsequent learning-related behaviors, both in and beyond the classroom. They underscore the importance of promoting enrichment in early childhood as a family strategy toward individual readiness to learn, a cornerstone of crystalized intelligence.