Why eldest siblings are brainier

April 23, 2026

Two brothers playing in a field

(The Economist) – SORRY, YOUNGER siblings. On standard measures of success, such as educational achievement and income, first-borns do better. Why? Stereotypes cast eldest children as responsible and younger ones as rebellious—but large-scale studies find no meaningful link between birth order and personality types. New research points to something rather different: germs. (Read More)