gladwell reported that a majority of canadian junior all- stars had one thing in common. >> gladwell: first half of the year. >> safer: so, january, february, march. >> gladwell: yeah, it's kind of amazing. look at the list-- it's like, january, january, january, february, february, february, and there's, like, one kid from december, you know. >> safer: gladwell says there's a simple explanation-- in canada, the birthday cutoff for junior hockey is january 1. >> gladwell: if the cutoff's january 1, and you're born january 5, you're an awful lot bigger than the kid born in december. and so, you... everyone thinks you're better. >> safer: and if you're better from the outset, you attract far more interest from coaches and get more practice. gladwell says that the predominance of winter birthdays extends into the pros. >> gladwell: you think that, at some point, these early advantages would dissipate. they don't, they... they snowball. >> safer: okay, but that's a sport. but how about in... in academics? >> gladwell: yeah, in academics, we see the same effect. the kids who are born close