At long last! Science has uncovered the mystery of why toddlers look so silly when they run.

It’s not for lack of practice, according to a new study in the Journal of Experimental Biology.

People have long assumed that little humans are just scaled-down versions of adults. Under this theory, their running looks weird just because they haven’t gotten good at it, yet.

But this is not the case, the researchers conclude. Instead, it’s because their small bodies are not built to generate the long, comfortable strides you would see in a marathon runner.

Little-kid legs are short, and as a result their muscles have very little time to generate power to launch their tiny feet upwards and forwards.

And so, their feet barely come off the ground. The result is the amazingly awkward and adorable toddler waddle we all know and love: