He Cheated? Blame The Genes
According to researchers, the dopamine receptor gene DRD4 is connected to promiscuous behavior, and people with the gene "were more likely to have a history of uncommitted sex, including one-night stands and acts of infidelity."
No word on any sexual orientation variables included in the study.
The report notes, however, that DRD4 is commonly known as the "thrill-seeking" gene, and is also linked to "loving horror movies" gene, the "gambling addiction" gene, and interestingly the "politically liberal" gene.
Hmm, I think all of my ex-boyfriends definitely had this gene.