It's the age old debate - which sibling is the biggest troublemaker! Well a recent study seems to have the answer... Second borns!
"The firstborn has role models, who are adults." the expert said.
"And the second, later-born children have role models who are slightly irrational 2-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 labor market and what we find in delinquency."
"It's just very difficult to separate those two things because they happen at the same time."
So there we have it - this might help settle some family arguments... Or maybe start a whole heap of new ones!