Early temperament as a predictor of language skills at 40 months

Influence of temperament on early neurodevelopmental disorders: a systematic review protocol

INTRODUCTION

Several studies have highlighted the role of temperament as a relevant construct to understand the wide variability observed in neurodevelopmental disorders (NDDs) such as autism spectrum disorder and attention deficit hyperactivity disorder. Some studies have pointed to temperamental traits such as strained control as possible precursors to the development of these disorders. In addition, how temperament influences high-risk populations, as well as intervention programmes aimed at families, has been investigated.

METHODS AND ANALYSIS

This paper presents the protocol that will be followed to carry out a systematic review, the objective of which is to know how child temperament is related to the different domains of development in children with NDD or the risk of suffering from it. The search strategy will be implemented in Web of Science (WoS Core Collection), PubMed, ERIC, PsycINFO and Cochrane databases. The risk of bias will be measured by the Newcastle-Ottawa Scale to carry out the integration of the results obtained to synthesis without meta-analysis will be used. This systematic review aims to improve scientific evidence for institutions and professionals and enhance the effectiveness of early care programmes for children with NDD and their families.

ETHICS AND DISSEMINATION

No express approval has been sought from any ethics committee because there is no primary data involved and no access to confidential patient information.

PROSPERO REGISTRATION NUMBER

CRD42023445173.

The influence of temperament and perinatal factors on language development: a longitudinal study

Early language development is characterized by large individual variation. Several factors were proposed to contribute to individual pathways of language acquisition in infancy and childhood. One of the biologically based explaining factors is temperament, however, the exact contributions and the timing of the effects merits further research. Pre-term status, infant sex, and environmental factors such as maternal education and maternal language are also involved. Our study aimed to investigate the longitudinal relationship between infant temperament and early language development, also considering infant gender, gestational age, and birthweight. Early temperament was assessed at 6, 9, 18, 24, and 30 months with the Very Short Form of Infant Behavior Questionnaire (IBQ-R) and the Very Short Form of Early Childhood Behavior Questionnaire (ECBQ). Early nonverbal communication skills, receptive and expressive vocabulary were evaluated with the Hungarian version of The MacArthur Communicative Development Inventory (HCDI). Our study adds further evidence to the contribution of infant temperament to early language development. Temperament, infant gender, and gestational age were associated with language development in infancy. Infants and toddlers with higher Surgency might enter communicative situations more readily and show more engagement with adult social partners, which is favorable for communication development. Gestational age was previously identified as a predictor for language in preterm infants. Our results extend this association to the later and narrower gestational age time window of term deliveries. Infants born after longer gestation develop better expressive vocabulary in toddlerhood. Gestational age may mark prenatal developmental processes that may exert influence on the development of verbal communication at later ages.

Receptive and expressive vocabulary performance in 2- to 5-year-olds in care: The role of different care types and temperament

The detrimental role of institutionalization in children's development has prompted the introduction of alternative care types designed to offer more personalized care. The current study aimed to test whether children in alternative care types (care villages, care homes, and foster care) performed better on vocabulary than those in institutions. The role of temperament, specifically perceptual sensitivity and frustration, and the interaction between temperament and care types on vocabulary performance were also explored. The study involved 285 2- to 5-year-old children from different care types, and they were assessed through receptive and expressive vocabulary tests and temperament scales. The results of the linear mixed model revealed that children in alternative care types exhibited significantly higher vocabulary scores compared with those in institutions. Moreover, perceptual sensitivity showed a positive association with receptive and expressive vocabulary skills and seemed to act as a protective factor by mitigating the lower vocabulary scores in institutions. Frustration moderated vocabulary outcomes differently for children in institutions and foster care, aligning with the diathesis-stress model and vantage sensitivity theory, respectively. The findings emphasize the positive role of alternative care types in vocabulary performance and the importance of children's temperamental traits in this process.

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.