The Sunk Cost Fallacy: How It Affects Your Life Decisions
The sunk cost fallacy is a cognitive bias that makes you feel as if you should continue pouring money, time, or effort into a situation since you’ve already “sunk” so much into it already. This perceived sunk cost makes it difficult to walk away from the situation since you don’t want to see your resources wasted.
Yes, that's a good example for something that follows the rational use case. But let's not take a toxic relationship extreme, I think in the case of a human relationship, the sunk cost may sometimes positivly contribute to the affection/intimacy/love. The sunk cost created memories, habits, foundations for a relationship that you cannot just suddenly ignore and only look at what comes in the future.
I think one must be careful about applying rational principles telling you to not listen to your emotions to subjects where reason doesn't play the main role.
So, a "sunk cost" is, basically, a cost that's already been paid. in comparison a prospective cost is one that's coming up. In the classic examples given for a sunk-cost fallacy, like the decision to maintain an older car or dump it for a new one; the sunk cost is all the past repairs and the initial purchase price. There's also all the realized benefits or profit on that side of the equation.
The generic fallacy is that people generally are influenced by those sunk costs. We generally continue something, or rather, are more likely to continue something we've been invested in- time, money, effort. Emotions. Where this fallacy leads us astray is that when those sunk costs are accrued, they can't be recovered. They have no bearing on the results of current decisions.
in the context of relationships, people change, and relationships between people change. We grow, maybe together. maybe we grow apart. One thing that will certainly not be happening is going back to what was.
and while it's perhaps churlish to discuss relationships in terms of economics... those costs and rewards have already been accrued. The question at hand isn't whether or not the relationship was worth it, but rather, is the relationship still worth it, and will it be in the future. if you suffer the sunk cost fallacy, you're basing your decision on what has been, and that's almost always a great way to get bit in the ass.
What if your relationship partner got badly sick and becomes more of a weight than before? Should you disregard what you have lived together because it is accrued and leave them because it is going to get worse in the future?
Depends, honestly. that's far to vague a scenario to give any solid answers.
but again. while we're using terms like "costs" and "benefits" don't forget, one of the "costs" involved could very well be one's own self respect. as well, there's other benefits, like still being with a loved one. Just because it's intangible doesn't mean it's without value.