The Science of Kissing: Could the Pill Be at Fault For Your Bad Taste in Guys?

Opposites attract, goes the saying, and we all know about those sayings. With one exception: That of the major histocompatibility complex, or MHC, the group of genes that determines how our immune systems will deal with disease. In short, the more diverse your MHC, the better your chances of fighting off viruses, bacteria and other intruders. All of us inherit your MHC variations through your parents, who, while they didn’t quite sequence one another’s DNA before deciding to start a family, did -- however unknowingly -- biologically select for a distinct MHC type during courtship. ...more

I stopped taking the pill when I became engaged to my husband and relied on barrier birth ...more