My, What a Sexy Immune System You Have

Why do women swoon over handsome men like Brad Pitt? Not merely for their rippling muscles or striking faces, but because of their robust immune systems, according to a new study. Men who appear seductively macho have higher testosterone, and the study found a correlation between testosterone levels and a strong immune system, explains LiveScience.

Researchers in the UK assembled 74 Latvian men in their early 20s and gave them a vaccine that triggers the production of antibodies. They then provided the men's photographs to Latvian women, who rated them for attractiveness. The results showed that the men with the most testosterone displayed both the strongest immune response and garnered the highest ratings of sexual appeal. "It's probably only a matter of time before we're eagerly awaiting the release of People's Sexiest Immune System Alive issue," adds Cassie Murdoch of Jezebel. (More health stories.)