I notice that all images of the past have these very somber-looking people. I understand painted portraits of royalty, wanting to showcase themselves as regal and a force to be reckoned with etc etc... But what about the regular people who got portraits done with their families that we see? There never seem to be any smiling faces. Whereas now - and for as long back as I've seen (pictures of my parents, and even grandparents) - people smile in photographs. You're TOLD to smile for pictures.
Was getting a picture taken not a happy occasion? Were smiles considered frivolous things to waste on such an expensive thing? I'm very curious, and would love to hear your insight.
Imagine a daguerrotype in about 1840. These would need the subject to sit still for many minutes. Now i suggest you try keep your smile in place for 20 minutes, maybe even five. That won't work. People looked "neutral" because it was the easiest to maintain for longer poriods of time.
Faster emulsions and flash photography surely made it easier to smile on a photo but i don't know if this also accounts for the cultural acceptance of smiling in photographs. Oral hygene might have played a role, as did the fact a lot of these photos where shot on formal occasions or where unique occasions in someones lifetime (i'm talking about the 1800's).
Source:studied photography in art school