Is it something I did? Helen Fisher explains why people fall out of love

This article was originally published May 24, 2018.

Falling in love is a bit of a mystery. As Dr. Helen Fisher told us in our article on stashing, "love is like a sleeping cat that can be awakened at any time." The systems in our brain that control the desire for long-term romance can be switched on by almost anything: a witty retort, a perfect outfit, a compliment from a third party. But how do our romance systems switch off? Statistically speaking, there are nearly as many instances of falling out of love as there are of falling in love. Almost inevitably, somebody is just not going to like you anymore. Why? What can kill a romantic spark?

We got back in touch with Fisher to find out what she could tell us about falling out of love.

She's a biological anthropologist, senior research fellow at The Kinsey Institute, and Chief Scientific Advisor to Match.com. She's written six successful books on the science of sex, love, marriage, and gender difference. We asked her why people stop like-liking each other and her answers, backed by decades of research and reflection, will not be comforting.

There are three big categories of reasons they don't love you anymore: it's you; it's them; it's someone else.

It's you

"Is it something I did?" If you are asking this question, you probably haven't been caught for any of the big stuff: cheating, lying, poisoning their cats. This won't save you. When I asked Fisher what kinds of things make people fall out of love, she immediately started naming much more prosaic love-killers. Snoring, failing to share an interest in hiking, and telling an unimpressive joke all got a mention. Note: she did not say "always telling stupid jokes." She said telling one bad joke. The triggers for falling out of love are hair-triggers. Fisher told me to think of the brain system controlling romantic love as an electronic circuit: "It can be turned on and it can be turned off like a switch. You can gain it in a minute or lose it in a minute." And the causes of the death of romance are every bit as unpredictable as those of its birth. Sometimes, even doing things really right can make someone lose interest. Fisher told me that she once fell out of love once after a vacation with her partner that was so incredibly good, that it made the prospect of returning to their normal life seem unbearably dull. It was soon over. People fall out of love with each other for millions of different reasons, and there's not much hope of predicting which it will be in any given case: "It could be just about anything, and you lose that glow, you lose that focus, you lose that motivation, you lose that charm."

Part of the challenge of holding someone's romantic interest is that their brain can be your enemy. Human beings have a built in bias towards the negative. We tend to remember and ruminate over negative experiences, even minor ones, much more than positive experiences. Fisher chalks this up to our evolutionary history. While it can be really pleasant to ponder people's positives, remembering the negatives has always been more useful, so we could avoid them in the future. This means that your date is much more likely to forget your perfect outfit, your scintillating conversation, and the hidden gem of restaurant you picked, than the fact that you chew with your mouth open. Their brain is wired to magnify your faults.

It's them

Other times, though, it's not something you've done. Of the infinite reasons that people lose interest in one another, a great many of them have nothing at all to do with that particular person. Suppose you're great and you and your love interest always have a good time together. Why did they stop calling? Is it because they are emotionally stunted semi-humans built for loneliness?  Not necessarily, argues Fisher. Romance is important, but it's not the only iron in our fires. A lot of the time connections fizzle simply because of the circumstances and priorities in people's lives.

A basic rule of thumb seems to be that the more someone has going on in their lives (bad or good), the less time they're going to have to fall head over heels for you. Fisher recounted a personal example in which an intense connection shorted out because her lover was going through some serious life events at the time. He told her "it's just not in my bandwidth [to continue our relationship]". She told me "It really wasn't about Helen Fisher; it was about where he was at." Of course, circumstances can change. Many years later, the pair picked up where they left off, and wound up becoming great lovers.

It's someone else

Fisher often talks about the search for love as a game in which "we are playing for life's greatest prize." However, she is also fond of reminding us that, in the game of love, "no one gets out alive."

Part of the reason for this is that love is not a two-player game; it's a war of all-against-all. A Thirst Games, if you will. Part of the reason for this is the natural human propensity for fomo. Even if we would prefer to be loyal and true partners, our romantic eyes have evolved to wander. She explains: "the brain is very well built to say 'well, this one's pretty good, but jeez I could do better.'" Even when we are not fully conscious of it, we are on the constant lookout for reproductive and romantic opportunities, and so are our partners. The reason someone loses interest in you is very often just that they've become more interested in someone else, or even the imagined possibility of someone else. Even when someone has eyes for you, they don't only have eyes for you.

ABC: Always be courting

Hyper-critical negativity biases, insufficient "bandwidth", and constant comparison. This doesn't sound much like romantic love. In fact, it's not always like that. Fisher research on people in love has revealed that, when the romance system in the brain is activated, it suppresses all of these things. Our negativity bias is suppressed and replaced by what Fisher calls "positive illusions", which are the rose-tinted lenses of the besotted. When we are in love, it's difficult to find fault with our beloved. When others are in love with us, we get away with far worse than bad jokes and forgetting the dishes. Likewise, our "bandwidth" can miraculously expand or change to make time for that special person. We even stop noticing other prospects, or at least notice them less. After all, says Fisher, we are a pair-bonding species.

But this doesn't mean we can lower our guard. Romantic love isn't permanent, and it's nearly impossible to tell when it will fade. If you want to keep a relationship going, Fisher is utterly clear that you can never stop seducing your partner. "One of the big mistakes that both men and women make is to wear really bad clothes around the house. Keep that courtship going. Just keep it going. We don't assume our will be around jobs forever, we don't assume we'll keep our friends forever. It's a mistake to think this person can't walk. The bottom line is don't take people for granted. It's a mistake. Not in this world."

Clifton Mark is a former academic with more interests than make sense in academia. He writes about philosophy, psychology, politics, and pastimes. If it matters to you, his PhD is in political theory. Find him @Clifton_Mark on Twitter.