 Contribution of different externalizing behaviours to the quality of maternal affective support in preschool 
The presence of externalizing behaviours in young children can be challenging for parents in several ways, including for preserving a good quality of affective support. Because externalizing behaviours are heterogeneous in their manifestations, their interference with the quality of maternal affective support in the learning context may vary. The predictive associations between the externalizing behaviours of opposition, physical aggression, hyperactivity-impulsivity, and inattention in children at 42 months of age with the quality of maternal emotional support at 48 months of age were tested in 195 mother-child dyads. Children’s externalizing behaviours were reported by the mothers, while the quality of affective support was observed during a cooperative literacy and numeracy task. Results show that only inattention uniquely and negatively predicted the quality of maternal affective support, controlling for child sex, family income, maternal education, maternal behaviour at 5 months, child prosocial behaviour at 42 months, and the other externalizing behaviours. These results suggest that during the preschool period, children’s inattention behaviours represent a greater challenge compared to other externalizing behaviours for mothers’ maintenance of affective support in the context of playful literacy and numeracy activities. Through a lower quality of maternal affective support in favourable situations for the practice of preschool competencies, children’s attentional difficulties could therefore weaken certain spheres of their school readiness.