If dad was a playboy, there’s a good chance that his sons and daughters will also be promiscuous, suggests a new study that identified a genetic link to such behavior. Moral objections aside, promiscuity can benefit a species because it often results in more progeny with greater genetic diversity. There are clear risks, such as having a higher chance of acquiring a sexually transmitted disease, but the genetic predisposition to play the field appears to be locked into the DNA of socially monogamous species, including humans.