If this sounds familiar, you aren’t being immature – you are experiencing adult sibling rivalry, a phenomenon rooted in ...

Sibling rivalry might not unique to humans. New scientific research shows that baboon siblings in southern Africa also feel jealousy toward each other. Sibling rivalry can be intense between young ...

I’m the older sister in my family, and growing up with a younger brother, I always felt the weight of setting a good example. And I tried my best, I really did, but he was a pro at pushing my buttons.