Sunk Costs in Humans, Mice, Monkeys, and even Role-Playing Games

 

It is often observed in humans that once enough time has been invested into something, it is difficult to just outright give up on it. This type of economic phenomenon is known as “Sunk Costs” and is seen in many different forms. It can take the form of many different situations in humans from something as simple as whether it is worth waiting for a better model phone or buying a new one now to more serious choices such as whether it is a good idea to leave an entire career path or change one’s area of study after investing years of one’s life into it. Indeed, sunk costs is observed extensively in humans. But is this behavior seen in different species? If so than what sort of thought processes influence such behaviors in animals that can perceive sunk costs? Or perhaps this is a behavior simply observed in just humans, implying a special level of thought that is exclusive to humanity. This is what researcher set to find out.

 

Dr. Sweiss was able to observe this pattern of behavior in mice by creating a maze that offers mice a “sunk cost” situation. The rates were placed into a “restaurant” that offered four different foods for the mice to choose from: plain pellets, grape, chocolate, or banana. The key in this experiment is that the foods were locked behind different wait zone for each of the different foods. For example, a rat was presented to the restaurant and “shops across the different options for a piece of food that it desires, such as grape. It would then go to the grape area and wait for a certain amount of time until the food dispenses. However, the mouse also has the choice in forgoing the grape and instead can move to a plain pellet and wait for less time. It was recorded that some mice were able to wait long enough to receive a higher reward such as a grape, though some mice only learned of this after opting for a more immediate option such as a plan pellet. The mice were able to prioritize foraging strategies accordingly once an economically bad decision had been made upon seeing alternatives that could have been taken instead. This demonstrates that animals, such as mice, are also able to experience Sunk Costs just like humans when given decisions.

 

It is not just rats that exemplify this understanding of costs and benefits, this type of behavior is also found in species of monkey such as Capuchin and Rhesus monkeys. Dr. Watzek had the monkeys play a game in which using a joystick, they operated a cursor that can dispense a treat if the cursor stays in line, if not, no treat is dispensed. Although initial trials showed that the monkeys were not that impressive with most monkeys not being able to attain the treat, some subjects later learned that a longer participation in the game will result in a reward, being the treat, and so learned to continue with the game despite initial difficulties. The results were found to be similar across the two species. This experiment also affirms the idea that Sunk Costs is not just a Human trait, but is also found across different species.

 

While Sunk Costs have been observed extensively in the lab in different animals, there are other more unorthodox ways to observe such phenomena in humans. One such medium that presents Sunk Costs is role playing video games such as The Elder Scrolls V: Skyrim. The game has a form of skill currency known as “skill points” which is a form of character advancement currency that advances a player’s skill as they play and they cannot be moved around unless heavy amounts of time is invested in-game. Skill points are used across different skill trees can be divided to essentially three different “career” choices: mage, thief, and warrior. By using skills and acting a certain way in game, different skill points are earned to help advance these traits. There may be times however that the player will find that investing in certain skill will be beneficial for one situation, but maladaptive for another. For example, a more warrior centric character will be able to go through with using the sword and shield proficiently to go about playing the game. However, when presented with an opportunity to make more money by playing as a thief, it becomes difficult to decide if it is worth a trade off due to the investment already as a warrior in terms of time. This replicates the “regret” found in Dr. Weiss’ experiments. Role playing games offer a different medium from the traditional studies on animals and the more dubious ethical experiments done on humans as the setting provides a near limitless medium to experiment with different levels and concepts of decision making that can be associated with Sunk Costs.

 

Future experiments such as those conducted by Dr. Sweiss and Watzek offer an opportunity to learn more about how humans and animals invest resources and times according to the ideas of sunk costs. Such research will be able a better understand the nature of resource allocation affects the behaviors of humans and animals and bring a better insight on what thought processes could drive different species to make the economic situations that they do, as well as how they deal with the consequences of making disadvantageous decisions.

References:

Sweis, B. M., Thomas, M. J., & Redish, A. D. (2018). Mice learn to avoid regret. PLOS Biology, 16(6). https://doi.org/10.1371/journal.pbio.2005853

Watzek, J., & Brosnan, S. (2020). Capuchin and rhesus monkeys show sunk cost effects in a psychomotor task. https://doi.org/10.31234/osf.io/qtgru