Twin Study Finds Language Delays Linked to Nature more so than Nurture
Based on the results from a large twin study, researchers found that language delays could be tied to nature more so than nurture. The team headed by distinguished professor, Mabel Rice from the University of Kansas, found that out of all language traits, three particular ones were heritable through genes.
"This finding disputes hypotheses that attribute delays in early language acquisition of twins to mothers whose attention is reduced due to the demands of caring for two toddlers," said Rice. "This should reassure busy parents who worry about giving sufficient individual attention to each child."
In this study, the researchers examined data on 473 sets of twins who were followed since birth. The team looked at language delays when the twins turned 24-months-old. They found that 47 percent of the identical twins and 31 percent of non-identical twins suffered from some kind of delay. The researchers noted that twins had double the rate of language delays than single-born children.
The researchers found that twins were more likely than single-born children to have late language development. 43 percent of twins' overall learning delays could be attributed to three language traits, which were vocabulary, combining words and grammar. The team concluded that these three traits were heritable, which suggests that nature might play a greater factor in language development than nurture.
"Twin studies provide unique opportunities to study inherited and environmental contributions to language acquisition," said Rice reported in the press release. "The outcomes inform our understanding of how these influences contribute to language acquisition in single born children, as well."
The researchers aim to study pregnancy and birth problems in relation to twins that had delayed language acquisition. They will follow the children at least until 2017.
The study was published in the Journal of Speech, Language and Hearing Research.