Featuring my 11-month-old nephew and an 18-month-old girl.

Girl is playing with a toy. Girl offers it to my nephew, who takes it, shakes it, and is very happy. Girl is smiling ear to ear. Nephew offers toy back to girl. Girl reaches out to grab toy -- nephew pulls it back just as she lays her hands on it. Girl walks away dejected.

Apparently babies learn sharing somewhere between 11 and 18 months.

I'm happy because I have this all on video.

First place would have gone to a friend's 3-year-old toppling an entire Christmas tree by pulling on a single ornament (no injuries), had I actually witnessed the event or aftermath. My nephew can't walk yet, but I'm sure my sister and brother-in-law will use that story as a lesson for baby-proofing their house.