This isn’t quite a Second Life related topic, but given my recent post on how to improve the look of your av’s face — if you were interested in that subject matter, you might be interested in this scientific paper. Here is a link to The Scientist, where you will find a less complicated version of a scientific paper on “a way to make photographs of faces more memorable or more forgettable”.
The interesting quote for me: “The photos that ranked highest on memorability didn’t have greater beauty, a bigger smile, a special gleam in the eye or a certain shape of the jaw. Rather, the computer was picking up on a multitude of tiny details and quirks that contributed to memorability but would be impossible to find and define on their own. There were no big distinct trends—instead, a thousand tiny tweaks, statistically tied to the memorability of the photos in the study.”
If you look at the photographs that accompany the Scientist article — and particularly the ones in the underlying article — you’ll be able to form your own conclusions. For me, and I’m very hesitant to say so because I have nothing except a “feeling” to go on, no scientific evidence whatsoever, the memorable faces are the ones that look like they are registering complex emotions and the the unmemorable ones are registering simple emotions, if any emotions at all. This is something that humans are good at reading when they look at a face but terrible at communicating, because it’s a kind of gestalt experience.
So, simplified for Second Life — to be memorable, tweak your av’s face so it looks like it’s experiencing some kind of emotion. I’ll bet that the most useful sliders you will find are the corners of the mouth (up/down) and ones to do with the eye opening, spacing, etc.