Certainly, when you get to actually “know” someone as part of relationship, a lot of other factors come into play. However, none of those will come into play if we never introduce ourselves to the other person. I think this is the one actual role that physical attractiveness plays since it forces us to get out of our comfort zone and go talk to a stranger. If they weren’t “attractive” in a surface manner, then we wouldn’t go through the trouble of meeting a perfect stranger. You can’t tell things like “health” and “kindness” from across the room. So, something else has to get your butt off the seat and go across and meet that person. That “thing” is physical beauty. Mother nature is very clever.