Study suggests germ exposure may explain why first-born siblings achieve more

Summary

A new study suggests that birth order effects on success (first-borns achieving higher education and income) may be linked to germ exposure rather than personality differences. While stereotypes portray eldest children as responsible and younger ones as rebellious, large-scale studies find no meaningful connection between birth order and personality. Instead, the research points to biological factors—specifically, germs—as a potential explanation for why eldest siblings tend to outperform their younger counterparts on standard success measures.