Toddler negative affectivity and effortful control: Relations with parent-toddler conversation engagement and indirect effects on language.

Evidence that early parent-child conversation supports early language development suggests a need to understand factors that account for individual differences in parent-child conversation engagement. Whereas most studies focus on demographic factors, we investigated the role of toddler temperament in a longitudinal study of 120 economically strained families. Specifically, we investigated the degree to which toddlers' negative affectivity and effortful control, considered together as a composite reflecting challenging temperament, accounted for variability in parent-toddler conversation engagement, and whether the frequency of that engagement mediated associations between toddler temperament and toddler expressive language skills. Toddler challenging temperament (i.e., high negative affectivity and low effortful control) and parent-toddler conversation engagement were measured at 18 and 30 months. Toddler expressive language skills were measured at 18, 24, and 36 months. As expected, a path model indicated inverse relations between toddler challenging temperament and concurrent parent-toddler conversation engagement at both 18 and 30 months. Unexpectedly, there were no direct associations between toddler challenging temperament and toddler expressive language skills either concurrently or longitudinally. However, we found indirect effects of toddler challenging temperament on later toddler expressive language skills via parent-toddler conversation engagement. Findings highlight the importance of considering toddler temperamental characteristics in addition to family demographics as important factors that account for variability in parent-toddler conversation engagement.