So, first-borns are both smarter and richer. ... They're also 4 per cent more likely to be overweight than second-borns and 10 per cent more likely than fifth-borns. However, first-borns are more likely to report better mental health.

Does birth order affect attractiveness?

Finally, birth order did not confound the effect of paternal age on off- spring attractiveness. ... They employed panel ratings of facial attractiveness based on photographs of the participants taken while in high school.

Do first-borns get better genes?

According to a recent study from the National Bureau of Economic Research (NBER), firstborn children do better than their younger siblings in school. ... For example, as Derek Thompson of the Atlantic notes, some might argue that it's genetic, in the sense that later kids are receiving diminished "genetic endowment."