The survey found oldest siblings have a better chance of getting rich.

If you’re a parent to multiples, you probably already see huge differences between your children. However, further down the line, your children’s earnings could be dictated by where they fall in the family. New research has found that firstborns tend to be more clever and earn more money than their younger siblings. The research conducted by the professor of economics at the University of Texas, Sandra E Black, has been ongoing since 2004 and found that eldest children tend to be all-around more successful and the reason why could be down to parents. According to the research, parents are in ways “less invested” in their parenting after their first child. Black says that the results suggested that parents are spending less time discussing school work with their younger children, resulting in slightly lower test results.

"We find some evidence that suggests that parents invest differently with earlier-born children,” she told Marketplace. “We see that parents spend more time helping them with homework. “The problem is, it’s hard to distinguish whether that’s the parents treating them differently, or the kids are different and the parents are just responding to it.”

However, this research isn’t conclusive as other research has been unable to prove the impact of the order in which you’re born has on us.