Jean Richard Séguin

Grounded in dynamic systems theory, which conceptualizes parent–child interactions as evolving systems of reciprocal influence over time, the main objective of this study was to examine which patterns of parent–child scaffolding in a problem-solving situation were associated with children's early cognitive development and to explore whether these patterns were influenced by prior child characteristics. A total of 193 mother–child dyads (109 girls) were observed during a number–image association task at 48 months. Children were predominantly White (95%) and of Canadian or European ethnic background. Three scaffolding phases were examined using the State Space Grid (SSG): modeling (problem-solving strategies are demonstrated by parents), guidance (characterized by shared participation in task execution), and fading (support is gradually withdrawn and greater initiative is shown by children). Only the fading phase was found to be associated with higher complex executive functioning (β = 0.30) and number knowledge (β = 0.42) 1 year later, at 60 months, controlling for prior child cognitive abilities. Furthermore, higher socioeconomic status, receptive vocabulary, and cognitive flexibility at 42 months were positively associated with fading. These findings highlight the importance of interactional processes that promote children's active participation in problem- solving for subsequent cognitive development.

Postpartum depression and parenting both play a role in shaping children’s future behavior. However, there is limited understanding of the interaction and the evolving relationship between depressive symptoms and parenting practices. This study aimed to investigate the bidirectional associations between maternal depressive symptomatology and parenting (maternal self-efficacy, maternal warmth, and maternal hostile-reactive behaviors) in the postpartum period and to assess the moderating effect of breastfeeding and partner support on these associations. Latent growth curve and multigroup analyses were estimated in a sample of 1551 mothers of the 3D pregnancy cohort. Maternal depressive symptomatology and parenting practices were concurrently associated. Bidirectional associations were found between maternal depressive symptomatology and maternal self-efficacy, but not for warmth or hostile-reactive behaviors. Mothers with high perceived partner support showed a significant association between increased maternal warmth and lower depressive symptoms at 24 months. In contrast, mothers with lower perceived partner support demonstrated stronger associations between early hostile-reactive parenting and later depressive symptoms, as well as a greater impact of declining self-efficacy on maternal depressive symptoms. Breastfeeding showed limited moderating effects, with no significant buffering impact on the associations between depressive symptoms and parenting practices. These findings highlight the protective role of partner support in mitigating the adverse effects of depressive symptoms on parenting and vice versa, emphasizing the need for interventions that strengthen maternal self-efficacy and partner involvement to promote maternal mental health.

Children who more effectively control their behavior on assessments of inhibitory control, a component of executive function, have better wealth- and health-related outcomes, including lower body mass index, suggesting that they may exert control across multiple contexts. Being breastfed also predicts later body mass index. One hypothesis is that breastfeeding provides regular practice at autonomous appetite regulation: Because mothers cannot gauge exact amounts of milk consumed from breasts, they may let infants use their own internal satiation cues to regulate consumption rather than rely on external cues (e.g., quantity of milk left in bottles). Indeed, multiple studies report that breastfed infants demonstrate better appetite regulation later on than bottle-fed infants. Beyond appetite regulation, however, breastfeeding may also provide early and regular inhibitory control training, more generally. To examine longitudinal associations, we conducted secondary analyses of data from the Québec Longitudinal Study of Child Development. When 572 infants were 5- and 17-month-olds, mothers reported on whether and for how long they breastfed. Children were later assessed on executive function and behavior, including inhibitory control assessed using both direct behavioral assessments and mother-reported hyperactivity and inattention (everyday indicators of poor inhibitory control). We found that breastfeeding during infancy predicted inhibitory control at 3.5 years of age, even after controlling for significant covariates, supporting the idea that breastfeeding may provide a natural means of introducing early and regular inhibitory control practice and that practice in one inhibitory control domain may promote improvements in other domains.

Substance use (SU) problems are critical public health concerns. This study investigated how childhood risk factors and cannabis age of onset (CAO) in adolescence predict later SU problems, using data from the two cohorts of the Quebec Longitudinal Study of Child Development (N = 306; 57% female; N = 1489; 54% female), followed from birth to age 23. A direct association between early CAO and increased cannabis use problems was found in males (cohort 1: β = -0.47; cohort 2: β = -0.22), but not in females. In both sexes, CAO was indirectly associated with later cannabis use problems via increased adolescent cannabis use frequency (cohort 1: ab = -0.41; cohort 2: ab = -0.35). Similar indirect associations were observed between CAO and other SU problems (including tobacco and alcohol), via adolescent cannabis use frequency (cohort 1: ab = -2.63). Parental cannabis use, adverse childhood experiences, and childhood externalizing behaviors (i.e., physical aggression and ADHD symptoms) were associated with early CAO and subsequent CU problems. These findings support developmental models linking early risk exposures to maladaptive substance use pathways and underscore the importance of prevention strategies targeting early cannabis initiation and modifiable early-life risk factors to reduce long-term SU-related problems.

The Highly Sensitive Person Scale (HSPS) measures Sensory Processing Sensitivity, a trait capturing individual differences in environmental sensitivity. This study of 186 young adults aimed to (1) validate and examine the factor structure of a Canadian French translation of the HSPS, (2) test associations with personality traits and mental health symptoms, and (3) investigate the moderating role of sex. Confirmatory factor analyses supported correlated two- and three-factor models. Path analyses showed that the HSPS subfactors were differentially associated with personality and mental health outcomes. Aesthetic Sensitivity was associated with more positive features of personality and mental health, whereas Ease of Excitation and Low Sensory Threshold were associated with more negative features. Sex moderated associations between HSPS subfactors and lack of perseverance, negative urgency, sensation seeking and prosocial behaviour, with stronger effects in males. The scale demonstrated good psychometric properties, supporting the validity of the Canadian French version.