Love at First Smell?

What do you look for in a romantic partner? Perhaps you'd like someone with a great sense of humor, a dazzling smile, or other fantastic qualities! Many visual and psychological aspects can shape our preferences of who we'd like to date. Surprisingly, science suggests that a major biological component that influences attraction is... wait for it... B.O.! That might sound gross, but there are scientific reasons behind it. Body odor is regulated by the many microbes present on the surface of and within our bodies.

Microbes release hormones, and body odor may help potential partners subconsciously learn more about each other's immune systems. One of the hormones released is oxytocin, which encourages social bonding and cuddling. When you smell a person's B.O., you are also smelling their major histocompatibility complex proteins, or MHC proteins for short. The MHC consists of genes that code for proteins on the surfaces of cells throughout the body. The proteins were formed by the exposure to microbes over one's lifetime, and help the immune system recognize threats. According to research, if someone's MHC differs greatly from yours (they've battled with different pathogens), they will smell good to you. It is possible that people with complementary, or different MHC's will potentially have healthier children because they genetically pass down immunity to a wider variety of pathogens.

MHC proteins

Picture Source: britannica.com