But when asked which doll is Barbie, the girls invariably point to a blonde. The idea that all these different dolls—none of whom look alike—can all be Barbie is confusing to moms too.

Benji Jones: Hello, and welcome to our Barbie experiment. Today, we're going to open up each of these three dolls and do a little bit of math to try to figure out what they would look like if they ...