Power of Birth Order

Of all the things that shape who we are, few seem more arbitrary than the sequence in which we and our siblings pop out of the womb. Maybe it's your genes that make you a gifted athlete, your training that makes you an accomplished actress, an accident of brain chemistry that makes you a drunk instead of a President. But in family after family, case study after case study, the simple roll of the birth-date dice has an odd and arbitrary power all its own.

The importance of birth order has been known—or at least suspected—for years. But increasingly, there's hard evidence of its impact. In June, for example, a group of Norwegian researchers released a study showing that firstborns are generally smarter than any siblings who come along later, enjoying on average a three-point IQ advantage over the next eldest—probably a result of the intellectual boost that comes from mentoring younger siblings and helping them in day-to-day tasks. My older sister always said she was smarter, but I didn't believe it. Now I wonder.

Source: Time Magazine October 29