title: Growth of infant communication between 8 and 12 months: a population study.
abstract: OBJECTIVE
  To describe changes in infant prelinguistic communication skills between 8 and 12 months, and identify factors associated with those skills.
  
  
  METHODS
  
  
  
  METHODS
  Parent questionnaire data for a prospective population-based cohort of infants in metropolitan Melbourne, Australia.
  
  
  METHODS
  1911 infants born November 2002-August 2003.
  
  
  RESULTS
  Infant communication (Communication and Symbolic Behaviour Scales (CSBS)) at 8 and 12 months. Potential risk factors: sex; prematurity; multiple birth; sociodemographic indicators; maternal mental health, vocabulary and education; non-English speaking background; and family history of speech-language difficulties. Linear regression models were fitted to total standardised CSBS scores at 8 and 12 months.
  
  
  RESULTS
  Social communication, especially the use of gesture, developed rapidly from 8 to 12 months. Female sex, twin birth, and family history were strongly associated with CSBS scores. The combined model accounted for 5% and 6% of the total variation at 8 and 12 months, respectively. CSBS score at 8 months strongly predicted CSBS score at 12 months (coefficient = 0.56, partial R(2) = 37.0).
  
  
  CONCLUSIONS
  There is a dramatic increase in communication skills between 8 and 12 months, particularly the development of gesture, which (as in previous studies) predates and predicts future language development. Risk factors explained little variation in early communication trajectories and therefore, based on our findings, this developmental course is more likely to be biologically predetermined. Rather than focusing on risk factors, we suggest that language promotion activities in otherwise healthy young infants should either be universal or, if targeted, be based on the level of communication skills displayed.
authors.affiliation: School of Human Communication Sciences, La Trobe University, Melbourne, Victoria, Australia. S.Reilly@latrobe.edu.au
authors.forename: Sheena
authors.initials: S
authors.lastname: Reilly
authors.forename: Patricia
authors.initials: P
authors.lastname: Eadie
authors.forename: Edith L
authors.initials: EL
authors.lastname: Bavin
authors.forename: Melissa
authors.initials: M
authors.lastname: Wake
authors.forename: Margot
authors.initials: M
authors.lastname: Prior
authors.forename: Joanne
authors.initials: J
authors.lastname: Williams
authors.forename: Lesley
authors.initials: L
authors.lastname: Bretherton
authors.forename: Yin
authors.initials: Y
authors.lastname: Barrett
authors.forename: Obioha C
authors.initials: OC
authors.lastname: Ukoumunne
mesh_terms: D001315:Australia; D002663:Child Language; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008603:Mental Health; D009035:Mothers / Q000523:psychology; D009633:Nonverbal Communication / Q000502:physiology* / Q000523:psychology; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D012959:Socioeconomic Factors; D014427:Twins