I found this article by Michael Zhang on the PetaPixel website going back to 2013. Click on any image in this post to read the full article, which shares other examples, but here are a couple of excerpts from his research, in part, based on an in-depth article by Nicholas Jeeves.
they apparently had a very different meaning back in the day:
"By the 17th century in Europe it was a well-established fact that the only people who smiled broadly, in life and in art, were the poor, the lewd, the drunk, the innocent, and the entertainment."
Want to be seen as upper class and as a person of good character? Don’t smile."
The three images below are my grandfather, probably taken around 1910; my wife's great grandmother taken around 1865; and my great grandparents around 1875. Not a smile in the bunch, although I love the shot of my grandmother on the right, probably around 1910. She still isn't smiling though.
Notice the classic technique in the portrait, complete with a little catch-light in her eyes. As far as the pose goes, there's a great story going back thirty-plus years ago that came out of PPA print competition. Supposedly there were multiple artists one year who all used the same similar pose of a bride with her hands together next to her cheek. Well, one of them claimed the pose was his.
Al Gilbert used to do an incredible program about the history of portrait photography. As the story goes, Al stepped in and showed the pose didn't belong to any of them, but the great masters of the 16th century!
So, learn how to capture good solid portraits; keep raising the bar on your skill set, especially in lighting; and keep building relationships with each potential client. And if you get caught up in the criticism of your work on various Facebook forums, listen to what's being said; consider how to make your work better and then remember what my old buddy Dean Collins used to say..."Beauty is in the eyes of the checkbook holder!"