Researchers conducted sweaty t-shirt tests to see if smell impacted the choice of a mate. Men wore t-shirts for two days and then women were tested on which smell they liked. Women preferred the smell of men who were genetically similar but had different immune systems. Inheriting different immune systems would give offspring a survival advantage. – WTF Fun Facts
Source: Evolution: Library: Sweaty T-Shirts and Human Mate Choice (pbs.org)
