The “sunk cost fallacy” (explanation here) is often held up as one way that normally rational people fall prey to silly, silly irrationality. And along those same lines, I’ve seen a number of folks try to apply this metric to relationships.
In pure economics, a sunk cost is when you’ve already spent money that you can’t get back. A classic example is continuing to invest in a crappy company so you don’t “lose” the cash you’ve already invested.
But that isn’t how relationships work.1
If you try to avoid this “fallacy” in economics, you’ll stop investing in a company when things go south. To quote Wikipedia:
Traditional economics proposes that economic actors should not let sunk costs influence their decisions. Doing so would not be rationally assessing a decision exclusively on its own merits.
And that makes sense when you’re talking about economics.
But it’s complete and utter bullshit when you’re talking about people.
Obligatory disclaimer time: Just because you’ve been in a relationship a long time does not inherently give it value. Especially if there’s a recurring pattern of problematic behavior.
In a typical relationship, there’s going to be tough times. There may even be horrible times. It doesn’t matter why that is – perhaps one partner lost a job, perhaps there’s a chemical imbalance that got out of hand, perhaps someone got ill, perhaps there’s a stressor that completely freaked out someone.
In those cases, when there’s not a consistent, ongoing pattern of problematic behavior, the sunk cost fallacy saves relationships.
Try this on for size: You are with a partner because they’re… well, for lack of a better word, fun. It’s good to be around them.
And then they get sick. Like, seriously sick.
And they’re not fun anymore.
Traditional economics – or some pure rationalism bullcrap – would have you dropping that partner like a hot stone. After all, they’re not making your life better right now.
Which is a hugely sociopathic and selfish way to behave.
The sunk-cost fallacy fails when it comes to most relationships because sometimes there’s really, really rough spots. It’s not merely an averaging out of how things are going in the relationship; it’s knowing how good things can be.
Armed with that knowledge, it’s possible to then address the rough patches as rough patches instead of some kind of traumatic disruption.
But a rough patch – even a massive disruption in the relationship – doesn’t mean you should suddenly ignore everything that came before.
1 Nevermind that the idea of quantifying the value of relationships by what you gain by them is abhorrent to begin with. Just stick with me here.