Step 1: wear a t-shirt for 3 days and 3 nights without deodorant.
Step 2: mail the shirt to Smell Dating.
Step 3: Smell Dating will mail you swatches from, uh, aromatically-enhanced t-shirts submitted by other users. Smell them.
Step 4: ask Smell Dating to connect you with a person whose smell you find appealing. Mutual matches will receive contact information.
That's Smell Dating, a project by artist Tega Brain. Right now, it's an experiment limited to 100 people in New York City. But it may take off and become a big thing. Tega Brain argues that the human sense of smell is an excellent way to discern relationship compatibility:
The olfactory apparatus is a nontrivial source of information and the extent of its impact on our social lives is currently unknown. However when it comes to long-term romantic partnership it may actually be riskier to ignore the powerful signal of scent than to rely on it. Smell researchers even speculate that high contemporary divorce rates may be related to the overuse of deodorants and the underuse of our natural olfactory intelligence.
-via David Thompson
The researchers speculate that a highly different MHC helped indicate a high degree of un-relatedness, which would be advantageous for mating; bringing greater hybrid vigor. The birth control pill exception might be due to an effect found in pregnant mammals, who prefer to congregate with family members, possibly for protection during pregnancy.
The researchers further speculated that the pill may then lead to people becoming attracted and marrying under the mis-guidance of artificial hormonal cues. Cessation of using the pill may then lead to a loss of attraction during marriage.