Welcome to the future, ladies and gentlemen.
Scientists know that the hormone called vasopressin is integral to the formation of social bonds. In the male brain, vasopressin is released during sexual activity and encourages a guy to form an emotional attachment to his partner. But in a survey of 1,000 heterosexual couples, men who had a certain type of vasopressin receptor gene were twice as likely to report dissatisfaction with their marriages.
Imagine a future where being vasopressin negative was something you flaunted on your Match.com page. If you were a women, why wouldn't you want to know about a potential mate's "aptitude for monogomy," as the scientists put it. Hell, if there was a scientific test that could tell you whether the guy who just proposed to you is a ticking cheat bomb, you'd be stupid not to make him take it. Of course, the vasopressin receptor gene might not be terminal for its owner's sex lives. After all, if we can increase the number of vasopressin receptors, we might be able to cure cheating altogether.
Then we can deal with the other tell-tale signs of a mid-life crisis.
In an experiment conducted on prairie voles, males were injected with an artificial gene that boosted the number of vasopressin receptors in their brains. Then each male was paired with one female. Several hours later, a second female was thrown into the mix, because voles likes to party.