London: According to a recent study, if you're older than your siblings, you're likely to be smarter than them.
Research by a team from Leipzig University in Germany claims to show each child after the first is slightly less bright as they have to "share" parents.
Scientists also suggest that having your parents' undivided attention means you end up learning more, which benefits the eldest child.
However, in a two-child family the eldest won't necessarily dominate. They have a six in ten chance of a higher IQ, so their younger relatives still have a strong chance of overtaking them.
As well as demonstrating a heightened intelligence, older children also displayed an increased perception of their brain power.
The study is published in the Proceedings of the National Academy of Sciences.
