The psychology and maths behind unstable relationships

Saba’s six-month relationship with her boyfriend had always been tumultuous. She complained that her boyfriend Akhil was way too needy, insecure, and unconfident. Akhil’s complaint was that he wasn’t getting as much from the relationship as he was putting into it.

While Saba is a beautiful, young, cheerful, extremely attractive woman, Akhil is definitely not what you would call attractive. He had average looks, uninteresting personality, and an average career with an average-paying job.

Everyone, including Akhil, wondered how he managed to get a girl like her. She was clearly out of his league. Despite this, they somehow clicked and entered into a relationship six months ago.

Now, it was time to throw in the towel. Saba was fed up with his constant ‘guarding’ and needy behaviors and Akhil with her egocentrism.

Marie was the total opposite of Saba. There was nothing special about her looks, nor her personality. She was a plain Jane. She had no curves, no facial symmetry, and no cheerfulness. Forget cheerfulness, her face wore a grim expression that seemed to say, “I want to make you miserable”. Resting bitch face was her all-the-time face.
Yet, about a year ago, a guy named Donald fell in love with her and they got engaged a few months later. Again, no one understood what Donald saw in her. He was very successful, confident, and attractive. He could get any girl he ever wanted.

As soon as they got engaged, problems began to surface in their relationship. Donald began to realize that she wasn’t worth it and started taking her for granted. This was upsetting for Marie who was truly, madly, deeply in love with him.

The distance between them grew and grew until they finally broke off their engagement.


Mate value and the economics of love

Think of mate value as an imaginary number floating above your head that tells people how attractive you are as a potential partner. The higher the number the more attractive you are.

Say you have a mate value of 8 (out of ten) and are considered by many attractive. Think of this as your average mate value because attractiveness can be subjective, varying from person to person.

Some may rate you 7 or 6 and some as 9 or 10. Few will rate you 5 or below.

We typically fall in love with people who have a mate value higher than ours. This follows from the basic economic principle that people will enter into an exchange of any kind (such as a relationship) only if they believe they will gain more from it than they lose.

When you purchase a good from the store, your perceived value of that good is greater than the value you exchange for it, i.e. your money. Had it not been so, the exchange wouldn’t have occurred.

Thanks to millions of years of evolution, the mate value of men and women is determined in different ways. 
In general, women who’re youthful, symmetrical, curvaceous, cheerful, and smiling are perceived to have more mate value and men who’re successful, confident, brave, famous, and handsome are perceived to have a mate value.

Now, based on this knowledge, let’s assign mate values to our characters Saba and Akhil. 8 for Saba and 4 for Akhil seems reasonable given their traits.

Evolutionary psychology predicts that a person of low mate value will engage in stronger mate retention techniques. Mate retention simply means retaining a mate for the purpose of reproduction and raising offspring. Once you attract a mate you got to retain it.

Since Akhil was holding onto a valuable reproductive resource when he was in a relationship with Saba, he had to guard his treasure fiercely. And because he himself had a low mate value, he knew that Saba was out of her league.

Saba, on the other hand, thought herself too valuable for Akhil and thus behaved in egocentric ways. It is this friction, the difference in their mate values, that motivated them to end their relationship.


At this point, it’s reasonable to ask, “Why did Saba fall in love with Akhil in the first place? Wasn’t that a mathematical impossibility to begin with?”
The answer to this question is that certain life events can change our perceived mate values. The math still holds but in a different way.

When Saba entered into the relationship she was going through a break-up. She desperately craved being needed, complimented and being showered with love and attention. She desperately needed to heal her broken heart and ego. Anyone who had the potential to do all this had high mate value in her eyes.

Note that Akhil didn’t need to go through any drastic life experience to fall in love with Saba because she already had a higher mate value than him. He could have fallen in love with her any day.

Akhil’s mate value in the eyes of Saba probably rose to 9 (or even 10) because she desperately wanted someone like Akhil to comfort her, attend to her, and need her as much as Akhil did.

But very soon reality kicked in and Saba’s distorted perception of Akhil’s mate value started adjusting itself. She didn’t like what she saw and set out on an unconscious mission to end the relationship by being egocentric and self-centered.

mate value joke

What about Donald and Marie?


On average, people would rate Donald on the mate value scale at 9 and Marie at 5. Again, it seemed mathematically impossible that Donald could have fallen for Marie.

Guess whose life was undergoing major changes when they did fell for one another?

Of course, it has to be Donald because Marie could have fallen in love with him any day. 

Donald had just lost his mother and was grief-stricken. Marie happened to look a lot like his mother.
So, Marie’s mate value rose to 10 in the eyes of Donald who forgot about good looks, curves, and cheerfulness. He just wanted his mother back. Unconsciously, of course.

But very soon, reality caught up and Donald’s distorted perception started fixing itself.

Equal mate value = Stable relationship

Our past life experiences can distort our perceptions and make us act in ways that seem to defy evolutionary logic. Life is complex and there are often myriad forces at play that shape human behavior but evolutionary psychology provides an excellent framework to understand why we do what we do.
People who have equal or nearly equal mate values are likely to have more stable relationships because there are little or no opposing forces at play rip that the relationship apart.
References:
DeIuliis, S. (2013). Effects of Mate Value Difference on Relationship Length and Satisfaction.
Hromatko, I., Bajoghli, H., Rebernjak, B., Joshaghani, N., & Tadinac, M. (2015). Relationship Satisfaction as a Function of Mate Value. Evolutionary Behavioral Sciences9(4), 242-256.
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