Science News Archive

It’s true – big sisters are smarter…

Here’s some news that confirms what our Dr Kat has suspected for some time – the oldest child in a family is likely to have a higher IQ than his or her siblings.  A Norwegian team found that first born children, or those who had lost their elder siblings and therefore become the oldest, scored higher on intelligence than their pesky younger brothers and sisters.  The team studied more than 250,000 men in Norway, and although the difference in IQ between siblings was small, it works out as being statistically significant.

What’s really interesting is that it’s not the absolute order of birth, but your position in the family that’s important.  Some researchers have suggested that differences between siblings are due to different levels of hormones or antibodies in the womb with successive pregnancies.

But this new study shows that it’s more likely to be social factors – such as the amount of time parents lavish on their kids – that are more important.  Scientists also suggest that the oldest brother or sister in a family might boost their IQ by helping out their younger siblings.

24th Jun 2007