Interesting… A recent study published in the journal Science shows that birth order influences IQ scores in boys/men. It’s not a big difference (just two points separate first born men from men with older siblings), but still… Please don’t tell my oldest brother about this! And definitely don’t tell Son #1 – he’d never let his little brothers live it down.
Interestingly, prior to age 12 this pattern isn’t evident, apparently because a “younger sibling, being linguistically and cognitively less mature, degrades the firstborn’s intelltectual environment.” Hah. Take that, big brother!
So why does this pattern emerge over time? One expert suggests that it may be because older children get an “intelligence boost” from serving as their younger siblings’ informal tutor “in the ways of the world.”
[Source: CBS News]