The oldest child may have intelligence on their side, but the second-in-line can use sheer mayhem and mischief to get their revenge.
Yep, a study has now confirmed your suspicions: the second child really is a bigger handful than the first - especially if they're a boy.
The research collected data from thousands of sets of brothers in Denmark and the US, and found that second children are 20 to 40 per cent more likely to be disciplined in school and enter the criminal justice system.
I find the results to be remarkable that the second-born children, compared to their older siblings, are much more likely to end up in prison, much more likely to get suspended in school, enter juvenile delinquency.
But before you rush off and pre-emptively berate your younger sibling or child for whatever wild crime they might commit next, take a good long at the apparently innocent eldest siblings.
Doyle thinks it might be all their fault, telling NPR:
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.
Even if parents nobly take time out of work to care for their second-born child, the are also helping out their first child by spending more time with them if they are still at home, the research suggests.
Plus, the early months and years of first-borns are more likely to be full of undivided attention.
But if you're the second-born in the family, there's no need to resign to yourself to a life in prison.
None of this is fixed as a matter of fact, as therapist Meri Wallace told parents.com:
You can consciously make a choice [to change your personality].
The data isn't applicable to everyone either: it only concentrated on Denmark and US, so may not hold across the world, and failed to include girls.