Do people really not know what running looks like?

Faster, higher, stronger -
wobbly!

When we run, our arms and legs swing in an alternating rhythm. Your left arm swings back as your left leg swings forward, same with the right. This contralateral rhythm is important for balance; the arms and legs counterbalance each other and help reduce rotation of the torso created by swinging the limbs. 

It turns out, however, that people don't really know this and they draw running incorrectly surprisingly often. Specifically, they often depict people running in a homolateral gait (with arms and legs on the same side swinging in the same direction at the same time; see the Olympics poster). I commented on a piece by Rose Eveleth at the Atlantic about a paper (Meltzoff, 2014) that identifies this surprising confusion in art throughout history and all over the world, and that then reports some simple studies showing that people really don't know what running is supposed to look like.

Rose covered the topic well; I wanted here to critique the paper a little because it's a nice example of some flawed cognitive psychology style thinking. That said, I want to say that I did like this paper. It's that rare thing - a paper by a single author who just happened to notice something and think about it a little then report what he found in case anyone else thought it was cool too. This is a bit old school and I approve entirely.