Having an older brother comes with plenty of benefits. Big brothers tend to look out for their younger counterparts, and despite the occasional rocky moment here and there, many siblings enjoy life-long close relationships. However, a new study finds an interesting downside: children with older brothers take longer when it comes to developing language skills.
The study, conducted by a group of researchers in Paris, France, builds upon prior research that had already established that having older siblings is associated with poor linguistic development. Now, researchers say they have refined those findings to come to a more specific conclusion: only children with an older brother exhibit these linguistic difficulties.
One would assume that children with older brothers would grow up around more conversation on a daily basis, thus speeding up their language development. Yet researchers say such children actually take longer than their older brothers to begin developing these skills.
Researchers studied more than 1,000 children from birth to the age of five-and-a-half years old. Each child's language skills were tested at ages 2, 3, and 5.5, using tests specially designed to measure numerous aspects of language development such as vocabulary, syntax, and verbal reasoning.
What the research team discovered was significant: children with an older brother had, on average, a two-month delay in their language development compared to studied children with an older sister.
As far as explaining this phenomenon, researchers have proposed two hypotheses. The first is that older sisters tend to talk more often than older brothers, which would compensate for parents potentially being less present than they were for their first child. The second hypothesis is that older sisters usually compete with their siblings less than older brothers for their parents' attention.
As of now, the study's authors say they can't say for certain why children with older brothers have a harder time developing language skills. In the future they would like to investigate if culture or location impacts the prevalence of these results.
The study is published in Psychological Science.