The relationship you have with your siblings are unlike any other.

When you were kids, you fought, hit, shouted and screamed at them all day long, and if you told your parents about their naughty behaviour? 'They didn't mean it, they're only young', are the words you'd hear them say.

And let's not get started on little brothers… they did just about anything to wind you up back in the day.

Well, older siblings, prepare to feel very smug because science has just found out something that you have known all along.

Little brothers are born naughty.

Yep, scientists studied datasets from Florida, all the way to Denmark and found that little brothers just can't help themselves from being bold.

In the report, named Birth Order and Delinquency (what a name), the researchers said: “In families with two or more children, second-born boys are on the order of 20 to 40 per cent more likely to be disciplined in school and enter the criminal justice system compared to first-born boys even when we compare siblings.”

Ouch!

It's not all bad though, as it has been found that younger siblings are also more laid back and funny.

“The most significant difference is in feeling the burden of responsibility – most (54 per cent) firstborns say they are more responsible than their siblings, compared to 31 per cent of last-borns.

“Younger siblings, on the other hand, are more likely to say they are more funny (46 per cent compared to 36 per cent of elder siblings), more easy going and more relaxed.”

The study ended by explaining that because older siblings were usually told to "keep an eye" on their younger brothers or sisters, "elder siblings are more likely to feel more organised and able to prioritise their own lives. Likewise, younger siblings are more likely to feel more favoured by their parents.”

So, there you have it.