We don’t normally think of mirrors as high-tech items, but in many ways, they are.
Primitive mirrors have been around for thousands of years, usually made of polished stone, and then of various metals. Mirrors similar to what we know today—a sheet of glass with a reflective back-coating—were invented nearly 2000 years ago in the Middle East and perfected during the Renaissance. But for all this time, they were extremely expensive to manufacture and only the wealthy could afford them; even then, they remained novelties. It wasn’t until after silvered-glass mirrors were invented in 1835 that it became possible to mass-produce them, making them accessible to ordinary people. And, of course, photography wasn’t invented until roughly the same time.
Think about what this means: until the mid-19th century, most people had little idea what they looked like. Wealthy people would commonly hire an artist to paint a portrait, but the poor would have to settle for fleeting reflections in ponds or windows. For most, clearly seeing one’s own face was a rare and novel experience.
I wonder how a person’s knowledge of their own appearance would affect their self-image. It’s difficult enough to have any kind of objective view of yourself; imagine doing it when you don’t even know what you look like. The whole concept of a self-image becomes far more difficult.
But now, most of us have a very good idea of our appearance. How does this inform our internal models of ourselves?
(Incidentally, it occurs to me that portraits of the wealthy might have been intended for this purpose: not as vanity objects, but as a means of simply knowing how one presented to the world. Being able to see yourself as others saw you would be highly useful for participating in formal society.)