Relative to pretty much any other mammal, humans have an absolutely atrocious sense of smell. But even our weakest sense is powerful enough to affect how we think...starting, of course, with how attractive other people look.
Oxford researchers probed the hitherto mystical connection between smell and human hotness back in 2007. The experiment itself was simple enough:
"We report an experiment designed to investigate whether olfactory cues can influence people's judgments of facial attractiveness. Sixteen female participants judged the attractiveness of a series of male faces presented briefly on a computer monitor using a 9-point visual rating scale. While viewing each face, the participants were simultaneously presented with either clean air or else with 1 of 4 odorants (the odor was varied on a trial-by-trial basis) from a custom-built olfactometer. We included 2 pleasant odors (geranium and a male fragrance) and 2 unpleasant odors (rubber and body odor) as confirmed by pilot testing."
Wait...the smell of rubber is unpleasant? Truth be told, I wasn't really aware rubber had a smell, but I suppose it smells like the inside of a tire shop. And who doesn't like going to the local Goodyear store and having a good sniff? Anyway, my questionable taste in smells aside, here's what they found:
"The results showed that the participants rated the male faces as being significantly less attractive in the presence of an unpleasant odor than when the faces were presented together with a pleasant odor or with clean air (these conditions did not differ significantly). These results demonstrate the cross-modal influence that unpleasant odors can have on people's judgments of facial attractiveness. Interestingly, this pattern of results was unaffected by whether the odors were body relevant (the body odor and the male fragrance) or not (the rubber and geranium odors)."
As always, I like to take these more abstract experiments and offer some practical advice. In this case, I would suggest that, if you fear you love someone only for their looks, have them work a week at a local rubber factory. (They have those, right?) If you can still stand to look at the smell of them, then they're probably a keeper. See how science is full of helpful hints?