Your Brain Reacts Differently When You're Not Monogamous, a Scientific Study Suggests

Wondering if your partner is cheating on you is one of the worst feelings in the world. Relationships are hard enough, but having to add on a conversation about infidelity? Yikes — hello, emotional roller coaster.

Many have gone through those hard moments of piecing together that gut-wrenching mystery, wondering whether your loved one is just stressed from a hard day or secretly lying to you with every passing moment. It would be so much easier if there was a scientific way to get the truth out. (And one that doesn't just involve guessing, even if there are some red flags to watch out for.)

It turns out, scientists hypothesize people who cheat actually have identifiably different brain chemistry than people who are being faithful to their partners. The scientific study, published in Archives of Sexual Behavior, compared brain activity in monogamous and nonmonogamous men by showing them images while scanning their brains with an fMRI machine. The researchers showed each group of men (one group who identified as monogamous, one group identifying as nonmonogamous) romantic and sexual pictures and recorded which areas of the brain were activated.

When shown romantic images, the brains of the monogamous men lit up on the right sides, including their orbitofrontal cortex, which is associated with decision-making. However, the brains of all the subjects of both groups reacted similarly when shown sexual images, suggesting only feelings of romance are changed when a subject identifies as nonmonogamous. "Results indicated that monogamous men showed more reward-related neural activity when viewing romantic pictures compared to nonmonogamous men," the study says. "These results demonstrate that the neural processing of romantic images is different for monogamous and nonmonogamous men."

It's important to note that, as with any scientific study, more research is needed before the underlying hypothesis can be proven, and the study included 20 men, so the size of participation needs to be considered. The study also didn't account for polyamorous relationships and didn't ask whether the subjects were literally cheating, just that the nonmonogamous individuals weren't with only one partner.

It would be nice if there was a way to carry an fMRI machine to check for signs of cheating, but that's closer to an episode of Black Mirror than real-life tech. Instead, hopefully, open communication will help filter out some of the confusion, and if nothing else, perhaps your instincts can point you in the right direction.