Risk Factors for Children's Receptive Vocabulary Development from Four to Eight Years in the Longitudinal Study of Australian Children

Abstract

Receptive vocabulary develops rapidly in early childhood and builds the foundation for language acquisition and literacy. Variation in receptive vocabulary ability is associated with variation in children's school achievement, and low receptive vocabulary ability is a risk factor for under-achievement at school. In this study, bivariate and multivariate growth curve modelling was used to estimate trajectories of receptive vocabulary development in relation to a wide range of candidate child, maternal and family level influences on receptive vocabulary development from 4–8 years. The study sample comprised 4332 children from the first nationally representative Longitudinal Study of Australian Children (LSAC). Predictors were modeled as risk variables with the lowest level of risk as the reference category. In the multivariate model, risks for receptive vocabulary delay at 4 years, in order of magnitude, were: Maternal Non- English Speaking Background (NESB), low school readiness, child not read to at home, four or more siblings, low family income, low birthweight, low maternal education, maternal mental health distress, low maternal parenting consistency, and high child temperament reactivity. None of these risks were associated with a lower rate of growth from 4–8 years. Instead, maternal NESB, low school readiness and maternal mental health distress were associated with a higher rate of growth, although not sufficient to close the receptive vocabulary gap for children with and without these risks at 8 years. Socio-economic area disadvantage, was not a risk for low receptive vocabulary ability at 4 years but was the only risk associated with a lower rate of growth in receptive vocabulary ability. At 8 years, the gap between children with and without socio-economic area disadvantage was equivalent to eight months of receptive vocabulary growth. These results are consistent with other studies that have shown that social gradients in children's developmental outcomes increase over time.

Predicting receptive vocabulary change from childhood to adulthood: A birth cohort study

“…Being a teenage parent was found to be a risk factor for delayed vocabulary skills in the MUSP cohort (O'Callaghan et al, 1995). By contrast, Taylor et al (2013) found teenage parenthood was associated with lower vocabulary knowledge in the LSAC cohort at the bivariate level, however, this association did not remain in the multivariate model when adjusting for other risk factors. Harrison and McLeod (2010) also utilised the LSAC data but included maternal age as a continuous variable and found that being older at the birth of the child was a protective factor against vocabulary delays.…”

“…Offspring of mothers from a nonEnglish Speaking Background have been shown to be at increased risk for vocabulary delays in both the LSAC and MUSP cohorts (Harrison & McLeod, 2010;O'Callaghan et al, 1995;Taylor et al, 2013) supporting theories of variation in language development when more than one language is spoken at home (e.g. Hemsley, Holm, & Dodd, 2006).…”

“…In looking at the influence of maternal mental health in the LSAC cohort, higher levels of psychological wellbeing were protective against vocabulary delays in Harrison and McLeod's (2010) study, with maternal mental health distress serving as a risk factor in Taylor et al (2013). Finally, there have been mixed findings in relation to the impact of cigarette use in the LSAC, with Harrison and McLeod (2010), reporting increased risk of vocabulary delay if either parent reported smoking in the household, whereas Taylor et al (2013) found children who had mothers that were current smokers were not at increased risk of lower vocabulary skills at 4 years of age. Again these contrasting findings, emerging from the same dataset (LSAC), may be explained by subtle differences in the categorisation of smoking in the household where both parents smoking in the household posed more of a risk for vocabulary delay than maternal smoking alone.…”

“…Given this high prevalence, previous work has examined the underlying parental, family and child factors which influence receptive vocabulary development at 4-5 years of age. These studies have utilised data collected from the Mater University of Queensland Study of Pregnancy (MUSP) (Lawlor et al, 2006;O'Callaghan et al, 1995), the Longitudinal Study of Australian Children (LSAC) (Harrison & McLeod, 2010;Taylor, Christensen, Lawrence, Mitrou, & Zubrick, 2013), the Ottawa Language Study (Beitchman et al, 2008) and the 1970 British Cohort Study (Law, Rush, Parsons, & Schoon, 2013). The studies' findings, discussed further below and summarised in Table 1, show that vocabulary acquisition varies widely as a result of individual differences across a range of childhood environmental factors.…”

“…There is consistent evidence that low maternal educational attainment is a risk factor for delayed receptive vocabulary skills at 4-5 years of age (Beitchman et al, 2008;Lawlor et al, 2006;O'Callaghan et al, 1995;Taylor et al, 2013), whilst higher levels of maternal education is protective against delays (Harrison & McLeod, 2010;O'Callaghan et al, 1995). There is mixed evidence with respect to the role of paternal educational attainment and receptive vocabulary knowledge.…”