Retronaut recently posted a fun collection of vintage photographs of children posing with toys. What makes them interesting is how unhappy they look from a contemporary point of view: confused, bored, even morose.  Thinking through the vintage photographs you have in your mind’s eye, though, you’ll recall that almost all vintage photographs include blank faces.  No smiling, no bunny ears… just people.

The contrast between then and now reveals that how-to-act-when-someone’s-taking-your-picture is a social construction. Smiling didn’t come naturally, it had to evolve socially.  Today parents teach their children how to smile for photographs and, perhaps, even to act gleeful with toys.

More at Retronaut.

UPDATE: There’s a great conversation going on in the comments.  Some have pointed out that early photograph technology required a long exposure time, making smiling impractical.  Others are sharing their experiences in other countries, where it is still the norm to stop smiling when the camera comes out, even if everyone is having a jolly time.  Lots of stuff to think about…

Lisa Wade, PhD is a professor at Occidental College. She is the author of American Hookup, a book about college sexual culture, and a textbook about gender. You can follow her on Twitter, Facebook, and Instagram.