Economists at the University of Edinburgh, Analysis Group and the University of Sydney put this down to the fact that eldest children receive more mental stimulation (read: undivided attention) from their parents early in life. In fact, the more kids they have, the less parents take part in reading, crafts and playing musical instruments – activities that have been shown to boost thinking skills.
The study, which used data collected by the US Bureau of Labor Statistics, examined nearly 5,000 children from birth until the age of 14, including their family backgrounds and economic situations.
The first born’s had higher IQ tests than their brother and sisters at as early as 12-months old. In addition, their reading and picture vocabulary were far more impressive than that of their younger siblings at the same stage.
Besides the bragging rights, this can be of major benefit later in life – from the level of education they reach to how much they earn in a year.
“Our results suggest that broad shifts in parental behaviour are a plausible explanation for the observed birth order differences in education and labour market outcomes,” Dr Ana Nuevo-Chiquero, Edinburgh’s University school of economics professor explained.
But it’s not all good news: previous studies have found a few downsides to being the eldest child. First-born’s are almost 20 per cent more likely than their siblings to develop short-sightedness. Plus, they’re twice as likely to feel pressure to succeed at school.