Random thought

"Mood lighting" generally means dimming lights to make a room darker, but not so dark that you can't see the other person well. Why would this be associated with intimacy and romance? My first intuition is that it has to do with smoothing out imperfections in people's skin, masking flaws, etc. But it seems like if this were the point, then we would find even darker lighting conditions more romantic, where only the essential features of our partner would be visible. Here's my hypothesis: when people are attracted to other people, their pupils dilate. The same thing happens in low light, but at sufficiently low levels of light, this would be difficult to observe. By dimming the lights just enough, we effectively create an illusion of constant attraction for ourselves. Any scientists in the room can feel free to attempt to test this...