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‘Love is not enough.’ A mathematical formula for relationship failure

Can science explain matters of the heart? A new mathematical model claims to elucidate marital dissolution. But the conclusion may be old news: Relationships take work.

Spanish mathematician Jose-Manuel Rey recently published his model in the journal PLoS ONE. “Scholars and therapists agree on the existence of a sort of second law of thermodynamics for sentimental relationships,” he wrote. “Effort is required to sustain them. Love is not enough.”

By charting and analyzing “sentimental dynamics,” which are prescribed by a couple’s intention to remain together ‘til death do they part, Rey reveals that unless “energy” is fed into a relationship, it will deteriorate over time. When both members of a couple have similar emotional attributes, their “optimal effort policy” will lead to a lasting union.

Although statistics show that two out of three marriages in the U.S. will end in separation or divorce, the majority of people do not believe that their own relationships will fail. Couples who believe their marriages are indestructible may put less effort or energy into sustaining them, which could paradoxically contribute to its higher risk of failure. Rey refers to this contradiction as the failure paradox: “How is it that a sentimental relationship planned to last will very probably break down?”

The fact that effort is necessary to sustain a long-term relationship is certainly nothing new, but what Rey’s model shows is that the most successful marriages have the most tolerable gap between the level of effort that a couple perceives as optimal for marital happiness and the level that is actually necessary to maintain it.

“The model is built from sociological data and facts accepted by psychologists and marital therapists,” Rey said in an e-mail interview. “Since it is a theoretical model without predictive power at the moment, it is consistent with data evidence but only in qualitative terms.”

Through revealing an underlying mechanism that may be acting in marital breakups, Rey said the model can teach couples something about how to make their relationships work. Couples beginning a long-term relationship should be prepared to put even more effort into it than they had initially expected, he said.

What about people already in a relationship? According to a PhysOrg article, Rey’s model “is also a reminder it is better to work on the relationship when the going is good, instead of relaxing and then finding the increased work necessary to fix a disintegrating relationship is more than considered reasonable.”

A Mathematical Model of Sentimental Dynamics Accounting for Marital Dissolution

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  • desiree

    why does a man start to think that he can step on hes women even though he says he loves her why would he make her feel so terriable

  • watchful

    desiree, the answer to your question is very simple: because he is allowed to.

  • Wanna cheat?

    20 years in, our marriage is being dragged behind the truck that hit us 10 years ago. We now have nothing but the relationship and the two almost grown kids that came from it. During my illness, I allowed so much neglect to occur that we now go nowhere, do nothing but work, goto church and watch tv. Now recovered at 44, I am depressed and miserable when I look at what we’ve hung on so hard to only become. Value without thrill. I wish that I could just go away and start over. Problem is, no matter where you go, there you are. I already know what faith says I ‘should’ do. What would science say?

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