In The Book of Skin Steven Connor talks about the cultural significance of the body's largest organ and examines how it operates as an expressive device. Marks on the skin (such as moles and freckles) have long been 'read' and 'mapped' in a manner akin to divination.
Connor quotes A Book of Knowledge (1696), which claims that "a mole on the belly, denotes whoredome, luxury, and gluttony" while "a mole on the side of the neck, shows that the person will narrowly escape suffocation." Moles can also provide information on the gender of the person concerned: "a man having a mole on the ancle, it bespeaks him to take on him the woman's part of an hen huswife: if a woman, that she shall wear the breeches" (97).
Or one of my favourites, from The Spaewife, or Universal Fortune-Teller (1845): "a mole on the outside corner of either eye, denotes the person to be of a steady, sober, and sedate disposition, but liable to a violent death" (98). You have been warned.
Skin is still 'read' in the 21st century, albeit in different ways. As Connor says, "innocence is unthinkable without the thought of an unmarked skin" (95). And skin is marked in so many ways, most obviously with colour. After watching beautiful Avatar last week, I was struck by the ease with which the human protagonist shifted into the body of another species. This shift is communicated, in part, by a spectacular change in skin colour.
The above is actually a fan made poster, and it highlights the real flesh contrast between species much more than the official poster:
Dude is blue. I find it interesting, but not surprising, that the designers chose to play down the contrast between Human and Na'vi skin in the official poster. Racial cross-dressing is a highly charged act. It suggests a certain politics, a power relationship that is not exactly conducive to romance. The Na'vi cannot 'wear' human bodies, even if they should want to. The transformation is one-way.
I'm too pooped to comment on the connection to the grotesque here. But it must be there, I've been writing skin/body/grotesque all day. Chunk of chapter four due on Tuesday. Should be doing that right now, see how you distract me internet!