sunk cost fallacy is a common flaw in logic that we used to justify everything from relationships to financial investments. Learn more about it here.

Sunk Cost Fallacy: “Is it worth it?” [#FallacyFridays]

Welcome to #FallacyFridays! On Fridays, we talk about the arguments that lack logic. You know, the ones that we should try our best to avoid. The sunk cost fallacy is no exception. And yes, that is the fallacy that we will be looking at today.

As with just about anything related to logic or philosophy, understanding the sunk cost fallacy doesn’t have to be this exercise that you read about here only, without any real life impact. Now, if you’re not familiar with this fallacy, you might be thinking that the name “sunk costs” has something to do with money. And you’d be right. But it is also very much relevant to something many of us crave other than money:

That thing called romantic love. 🥰

But before we get into it, I want you be aware of a tool that may help you understand this and other fallacies. If you’re the type of person who learns better by writing or typing, download this FREE digital copy of “#FallacyFridays: The Workbook.” It was designed to follow alongside #FallacyFridays lessons in order for you to better understand logical fallacies.

Sunk Costs and romantic relationships

Let’s pretend that you have been in a relationship with your significant other for 7 years. You’re approaching 30 at this point, meaning that you’ve spent nearly all of your 20’s in this relationship. You two hit it off. You gave each other the bougiest gifts, some so expensive that you had to pay in installments. The chemistry was natural and easy. At least at first. But that understated bonding that’s supposed to kick in towards that 2 year mark never made its appearance. The energy between you two was up and down; the liveliness that kept you two in high spirits around each other would be here one day and gone the next.

Then came the teasing. At least that’s what your partner called it. But the “teasing” would consistently be about things that your partner knew were your insecurities. Things that you have told them in those intimate, vulnerable moments during your honeymoon phase. During that sweet time, your partner met your insecurities with love and understanding. But these days? These days, they tell you:

“Ugh, don’t do that.”

“You need to get over it.”

“It’s just a joke.”

And your favorite one: “If something affects you, it’s because you’re letting it affect you. That’s not my fault. That just means you have stuff to work on.”

And even worse? The jokes sometimes slip in front of their parents.

4 years into the relationship and your partner is now your spouse. The “jokes” continue. But now your partner is also overly critical about your clothing choice, hairstyle, and even some of the friends you keep for no reason other than the fact that they are not his type.

You suggest to your partner that you two get marriage counseling, but your partner insists that it is for pansies. And you tell your friends about this and the “jokes” they’d make. Your friends insist you divorce. But you can’t seem to make your way around that decision. “I’ve invested so much in this relationship. I spent so much money and time with them. I’ve told them every single weakness and insecurity I have. Shoot, I practically gave them my 20’s. And now we’re married. I’ve given so much. I can’t just throw it all away. Nah, we have to keep going and figure out how to make it work.”

And that right there, is what makes this the sunk cost fallacy.

The sunk cost fallacy occurs when you decide to continue something based off of the investment (or “sunk cost”). That sunk cost can be time, money, energy, etc.

This can include anything from continuing a business that is bound to fail based off of the huge $14,000 investment it took to start it to continuing in an unhealthy relationship because of the energies that were required to maintain it.

Why the sunk cost fallacy is fallacious (and one instance where it might not be)

There are good investments. And there are terrible ones. In either case, they goodness or badness of an investment is determined by the same thing: its outcome.

The sunk cost fallacy works backwards; it focuses on input instead of the output. And since large investments can be placed in both good and bad things, using a large investment as a reason to continue something isn’t a reliable way to go.

However, if you are in a situation where you know, realistically-speaking, that further investment will lead to a positive turnaround compared to your currently dire situation, that is not fallacious. Keep in mind, though, that this instance considers both the investment and the outcome; not just the investment only.

Using only your investment in something as a reason to continue it–whether it be a relationship or a business venture–is not a good reason. Click To Tweet

Pro-tip: Make a list of all of the ways you might be justifying potentially bad decisions merely by the investment you’ve put into it. We are more likely to do this with circumstances we are most emotionally-invested in, so start by looking at the circumstances that have your heart the most.

Quiz time!

Now that you’ve learned how the sunk cost fallacy works, here’s your chance to test your understanding of it. Which of the following answer choices contains the sunk cost fallacy?

A. “I love her but it annoys me when she does not seem to have the same enthusiasm to touch me like I have towards her. I think it’s worth bringing it to her attention.”

B. “You have a monthly membership to your local gym, but you never go. Don’t you think that’s an unwise use of your money? Throwing your money away and not using the service when you could save it instead?

C. “Yo, this restaurant is bougie as hell. $73 for a small dinner plate and cake for dessert?! Man, you better eat every last drop we’re about to get so it’s worth the money I spent on it. I don’t care if you think it tastes nasty. Eat it!

D. “Thanks to your investment in our business, you took us from nearly quitting this business to giving us another chance. We’ve made more profit now than we have had in the 5 years we’ve been operating. Thank you for believing in us and our vision.”

Coming Soon
Which one of the following answer choices contains the sunk cost fallacy?
Which one of the following answer choices contains the sunk cost fallacy?
Which one of the following answer choices contains the sunk cost fallacy?

Wanna see if your answer choice was correct? Want the explanation behind the correct answer choice? Get FREE access to the Fallacy Fridays Answer Key and be notified about all future Fallacy Fridays posts, quizzes, and answer explanations!

Sunk Cost Fallacy: \