Research into how monkeys see and process information and recognise faces in various orientations has thrown up quite the interesting fact -- our faces may have evolved to resemble the pink blobs of a monkey's arse.
The actual, serious paper explains the similarities between our faces and monkey arses, saying: "The current study shows chimpanzee’s expertise in recognizing behinds and suggests they process the bright pink sex swellings of female chimpanzees configurally and in a similar way as humans process faces."
Hence the suggestion that our swelled up noses are meant to be parts of chimp's bottom. and our mouths, well, our mouths would be something very bad indeed.
Gradually, as we turned from chimps to people in that 13-million year social experiment the planet did, we also turned from recognising people by the shape of their bumholes to how their faces look, with the bottom-obsessed researchers saying: "The findings of our study suggest that over human evolution the face took over important properties shared with the primate behind and largely replaced its socio-sexual signaling function, making our species attuned to faces."
So when you look at a photo of, say, Susanna Reid, and feel happy and sad and confused all at once, it's just your internal chimp trying to work out where things are supposed to go. [PLOS ONE via Motherboard]