Remember all those times in your childhood when you swore your parents were favouring your older brother? It turns out you mightn't have been too far off the mark: according to a study out of the University of Edinburgh, first-born children are smarter than their siblings.
In order to explain the "birth order defect" and why some children born earlier in the family get better education and make more money, the study authors analysed a whopping 5,000 children from birth to the age of 14.
The children were assessed and given reading, letter-matching and picture vocabulary tests every two years, and astonishingly found first-born children had higher IQ scores than their younger siblings by the age of one.
If this angers you and you're struggling to bite the bullet, blame it on your parents. The study revealed that while all the parents with multiple children gave all their kids the same levels of emotional support, first-borns received greater levels of intellectual support, which in turn improved their thinking skills.
The results also showed parents did less brain-boosting activities with their younger kids such as doing arts and craft, playing musical instruments and reading to them. The final nail in the coffin - which we really hope isn't the case for you - is that mothers are also more likely to take risks after their first child, e.g. like smoking whilst pregnant.
So if your older brother is smarter and more successful than you, remind him he probably got preferential treatment as a child.
Meanwhile, another recent study found the youngest sibling is the funniest.
In fact, the study, which saw 1,800 British adults rate their personality traits, found that 46 per cent of them considered themselves the comedian of the family (compared to 36 per cent for firstborns.)
This article originally appeared on Men's Health.