Research out of the US claims second-born children are more likely to misbehave, sometimes with severe consequences.
Massachusetts Institute of Technology (MIT) economist Joseph Doyle's research suggests the "curse of the second-born child" could be true.
Prof Doyle and his colleagues collected data from thousands of sets of brothers in both the US and Europe that proved second-borns, particularly boys, are more inclined to be rebellious.
Second-born children are 25 to 40 percent more likely to get into trouble at school or with the law than their older siblings.
The actions of children can be attributed to the parenting styles that accompany birth order, Prof Doyle told NPR.
First-born children often get undivided attention from their parents, while their younger siblings have to share. The family dynamic can also change as the family grows.
"The firstborn has role models, who are adults. And the second, later-born children have role models who are slightly irrational two-year-olds, you know, their older siblings.
"Both the parental investments are different, and the sibling influences probably contribute to these differences we see in the labour market and what we find in delinquency. It's just very difficult to separate those two things because they happen at the same time."
It doesn't mean that second-born children are destined to live a life or crime and mischief - just that birth order may play a bigger role than first thought.