For better or for worse, older siblings play a pretty big role in their younger siblings' lives - especially in big families. In fact, a new study shows that a younger child's language development and vocabulary skills may depend heavily on her interactions with older sibs.

The study, published online in the journal Pediatrics, looked at the relationships of older siblings and their younger brothers and sisters and compared this with how well these younger kids did on language and vocabulary assessments. The older siblings were scored based on how they interacted with their younger relations. Researchers were looking to see how well the older sibs knew their younger sibling's abilities and whether or not they gave positive feedback when appropriate.

As for the younger siblings, they were given standard vocabulary tests to see how well they knew the words for different objects.

Researchers found that - in general - children with lots of older siblings tended to do worse on language tests than those from smaller families. The theory here is that these younger kids just get less in the way of resources and time from their parents.

But the researchers also found that when older siblings scored high in their interactions with younger siblings, those younger kids did better on their language assessments.

Right now, this link is just that - a link. Researchers don't know if the kids had better language skills because they had better relationships with their older siblings, or if they had better relationships with their older siblings because they had better language skills. They also don't know if the interactions between siblings had to be positive or if siblings who fight all of the time (they are still interacting, right?) see the same benefit when it comes to language development.

So more studies are definite in the works. But in the meantime, researchers think it's worth supporting the relationships between older kids and their younger siblings - especially in large families where the youngest may need the most help with language skills.

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