Many factors influence how your child turns out; dont attribute large effects to a subtle factor such as birth order. But the debate over the impact of birth order gained new urgency this summer when the results of a new study were announced: Firstborns IQs tend to be higher than those of their younger siblings.
Do firstborns get better genes?
According to a recent study from the National Bureau of Economic Research (NBER), firstborn children do better than their younger siblings in school. For example, as Derek Thompson of the Atlantic notes, some might argue that its genetic, in the sense that later kids are receiving diminished genetic endowment.
How does sibling order affect personality?
Furthermore, some studies confirmed the idea that sibling position can shape personality. The older siblings were therefore not only born first but also simply older. It has long been known that adolescents become more conscientious as they age. This trend could account for a large part of the results.