Twins more Prone to Language Delay than Single-Born Counterparts

The "twinning effect"--a language phenomenon that can disadvantage some twins as opposed to their single-born counterparts--can result in developmental delays. However, a recent study published in the Journal of Speech, Language and Hearing Research found that the issue was more common among identical twins than non-identical ones.

For the study, researchers examined 473 sets of twins who were followed since birth compared to single-born children. Findings revealed that 47 percent of 24-month-old identical twins dealt with language delays compared to 31 percent of non-identical twins. Furthermore, twins were twice as likely to suffer from late language emergency than single-born children. 

"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 lead study author and University of Kansas professor Mabel Rice, in a news release. "This should reassure busy parents who worry about giving sufficient individual attention to each child."

Rice said that prematurity and birth complications are typically more common in twins, which can also affect issues with learning and language, overall.

Language emerging later in life can mean that a child is below age and gender expectations in the number of words they speak and combining two or more words into sentences. Furthermore, study findings revealed that 71 percent of two-year-old twins were not combining words compared to 17 percent of single-born children.

In 2012, the group was granted $2.8 million by the National Institute for Deafness and Other Communication Disorders for a fourth five-year-cycle to enable the monitoring of the twins as the matured through adolescence. Researchers followed around 1,000 sets of Western Australian twins from their first words. In addition to formal language tests, researchers collected genetic and environmental data based on assessments of twins' siblings.

At this time, the study authors are currently conducting research involving pregnancy and birth risks for late talking in twins; the study will continue at least until 2017.