For some kids, any mistake in life always seemed to invite a comparison to their apparently more accomplished sibling. For a kid, it seems that getting caught spray-painting mean things about the principal on a wall wasn't bad enough without a reminder that their sister was valedictorian.
And even if this doesn't happen within a family, a lot of kids discovered that their accomplishments were being compared to what other parents bragged about. And in some cases, it didn't seem like those boasts could possibly be true.
But now, if one parent were to tell their child, "You know, Jack down the street already has four college degrees" when the youngster doesn't feel like doing homework, we now have confirmation that it might actually be true.