When it comes to your first born, you're going through all the milestones and developmental stages for the first time, and however they happen with your baby is completely normal to you! But with subsequent children, you may think that their development is influenced by their older siblings. For example, it wouldn't be out of the realm of possibility to assume that your second or third baby will talk sooner and develop their language skills quicker since they have their older siblings to mimic and emulate every day.
But according to a new study, the opposite might actually be true! Researchers at the French National Center for Scientific Research found that children who grow up with an older sibling actually develop their language skills slower than those with no older siblings. More specifically, they found that older brothers actually impact the language skills of their younger siblings the most.
To come to that conclusion, researchers studied the data collected from 1000 children who were followed from birth to 5 1/2 years old in the mother-child cohort EDEN. Language skills were evaluated at 2, 3 and 5 1/2 years of age. The children completed tests that measured things like vocabulary, syntax, and verbal reasoning. They found that children who had an older brother had a 2-month delay in language skills on average. Children with an older sister demonstrated language development identical to children with no older siblings.
It's an incredibly interesting study, and the researchers had a couple of hypotheses that may explain the developmental disparity. It's possible that older sisters are more willing to speak to their younger siblings, which can greatly impact their language development. It's also possible, according to researchers, that older sisters are less likely to try to compete for parental attention than older brothers. Obviously, so many factors come into play when it comes to language development, like parental involvement, economic status, and culture. But this study really highlights how different subsequent children can be, and just drives home that we can't assume things will go a certain way with any of our kids. We'd be interested to read more about this sibling-specific language research!