title: Levers for Language Growth: Characteristics and Predictors of Language Trajectories between 4 and 7 Years.
abstract: BACKGROUND
  Evidence is required as to when and where to focus resources to achieve the greatest gains for children's language development. Key to these decisions is the understanding of individual differences in children's language trajectories and the predictors of those differences. To determine optimal timing we must understand if and when children's relative language abilities become fixed. To determine where to focus effort we must identify mutable factors, that is those with the potential to be changed through interventions, which are associated with significant differences in children's language scores and rate of progress.
  
  
  METHODS
  Uniquely this study examined individual differences in language growth trajectories in a population sample of children between 4 and 7 years using the multilevel model for change. The influence of predictors, grouped with respect to their mutability and their proximity to the child (least-mutable, mutable-distal, mutable-proximal), were estimated.
  
  
  RESULTS
  A significant degree of variability in rate of progress between 4 and 7 years was evident, much of which was systematically associated with mutable-proximal factors, that is, those factors with evidence that they are modifiable through interventions with the child or family, such as shared book reading, TV viewing and number of books in the home. Mutable-distal factors, such as family income, family literacy and neighbourhood disadvantage, hypothesised to be modifiable through social policy, were important predictors of language abilities at 4 years.
  
  
  CONCLUSIONS
  Potential levers for language interventions lie in the child's home learning environment from birth to age 4. However, the role of a family's material and cultural capital must not be ignored, nor should the potential for growth into the school years. Early Years services should acknowledge the effects of multiple, cascading and cumulative risks and seek to promote child language development through the aggregation of marginal gains in the pre-school years and beyond.
authors.affiliation: Newcastle University, Newcastle upon Tyne, United Kingdom; Murdoch Children's Research Institute, Melbourne, Australia.
authors.forename: Cristina
authors.initials: C
authors.lastname: McKean
authors.affiliation: Murdoch Children's Research Institute, Melbourne, Australia; University of Melbourne, Melbourne, Australia; The Royal Children's Hospital, Melbourne, Australia.
authors.forename: Fiona K
authors.initials: FK
authors.lastname: Mensah
authors.affiliation: University of Melbourne, Melbourne, Australia.
authors.forename: Patricia
authors.initials: P
authors.lastname: Eadie
authors.affiliation: La Trobe University, Melbourne, Australia.
authors.forename: Edith L
authors.initials: EL
authors.lastname: Bavin
authors.affiliation: The Royal Children's Hospital, Melbourne, Australia; Murdoch Children's Research Institute, Melbourne, Australia; University of Melbourne, Melbourne, Australia.
authors.forename: Lesley
authors.initials: L
authors.lastname: Bretherton
authors.affiliation: Murdoch Children's Research Institute, Melbourne, Australia.
authors.forename: Eileen
authors.initials: E
authors.lastname: Cini
authors.affiliation: Menzies Health Institute Queensland, Queensland, Australia; Murdoch Children's Research Institute, Melbourne, Australia.
authors.forename: Sheena
authors.initials: S
authors.lastname: Reilly
mesh_terms: D001724:Birth Weight; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007182:Income; D007804:Language Development; D007805:Language Development Disorders / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control / Q000523:psychology; D000067010:Literacy; D008960:Models, Psychological; D002666:Psychology, Child; D011640:Public Policy; D012111:Residence Characteristics; D012307:Risk Factors; D012959:Socioeconomic Factors; D035862:Vulnerable Populations