There are millions of things siblings argue about: who's mum's favourite, who gets the last Wagon Wheel, and who is the smartest, funniest or most athletic sibling. 

Luckily, a team of expert researchers at the University of Edinburgh has answered one of the eternal familial questions.

New study says oldest is the smarter sibling. I would argue this point but apparently I am not smart enough….or my sister scares me.

— Kirk Pederson (@RinglerunSk) February 10, 2017

If you are the oldest sibling, you officially have something to brag about because new research is suggesting that first-born children are actually smarter than their younger counterparts.

The research was based on IQ scores, which came out as overwhelmingly higher for older siblings.

A group of 5,000 children were monitored for the research, from the Journal of Human Resources.

Nothing brings an equal amount of pride and anger than realizing that your sibling is cooler/funnier/smarter than you smh

— radric delantic (@LindsayMcCaskey) January 22, 2017

Experts think that this may be because the first-born receives more mental stimulation from their parents, in comparison to their younger siblings.

Pity we couldn't find a way to outsmart our sister into not fleecing our wardrobes growing up.