Late speech in toddlers should not be blamed on family environment, mother's education, income or parenting style, says a study that would come as a reassurance to many parents.
Professor Mabel Rice at the Telethon Institute for Child Health Research in Australia, in partnership with Curtin University of Technology and other researchers analysed the speech development of 1,766 children in Western Australia.
The studied children were from infancy to seven years of age, with particular focus on environmental, neuro-developmental and genetic risk factors. It is the first study to look at predictors of late language.
Boys were three times more likely to have delayed speech development, while a child with siblings was at double the risk, as were children with a family history of late talkers.
The study found that family environment does not contribute for such development. They also found that mother's education, income, parenting style or mental health have no impact on a child's likelihood of being a late talker.
"Some people have wrongly believed that delayed language development could be due to a child not being spoken to enough or because of some other inadequacy in the family environment," a researcher said.
"This is clearly not the case and I hope these findings will reassure many parents that delayed language is not a reflection on their parenting or the child's intelligence.
"What we also know from this study is that most children who are late talkers do in fact fall into the normal range of language development by the time they are seven years old," said study coordinator associate professor Kate Taylor.
However, she said that it is important that children who are delayed in their language development by 2 years of age are professionally evaluated by a speech pathologist and have their hearing checked.
By 24 months, children will usually have a vocabulary of around 50 words and have begun combining those words in two or three word sentences.