(Photo by Tumisu on Pixabay)
STANFORD, Calif. —Â Ever found yourself clinging to something, whether it’s an old car or a relationship, despite knowing it’s not in your best interest? Well, you’re not alone. Scientists have long puzzled over why humans and animals alike often overvalue what they’ve invested, even when it defies logic. Now, researchers at Stanford Medicine have made a significant breakthrough in understanding this phenomenon and its connection to a brain chemical called dopamine.
Stanford scientists explored the neural basis for this behavior, often referred to as the “sunk cost fallacy.” This fallacy involves valuing something more because of the effort, time, or resources already invested, even when continuing to invest makes no sense.
“We make fallacious decisions based on what we’ve invested in something, even if the probability of actually gaining an objective advantage from it is zero,” says study author Dr. Neir Eshel, assistant professor of psychiatry and behavioral science at Stanford Medicine, in a media release. “And it’s not just us. This has been shown in animals across the animal kingdom.”
Stanford Medicine researchers conducted experiments on mice to investigate the role of dopamine in this phenomenon. Dopamine is a brain chemical often associated with pleasure, learning, and habit formation.
Researchers wanted to understand the difference between “wanting” something and “liking” it.
“You can want something very, very much even though you don’t even like it very much. Or vice versa,” notes Dr. Eshel.
Their experiments involved mice and measured the effects of varying effort or “cost” to obtain a reward. The cost ranged from simple tasks to more challenging or uncomfortable actions, such as electric shocks. The reward, in this case, was either sugar water or direct stimulation of dopamine release in the mice’s striatum, a brain region known for its involvement in motivation, movement, learning, and addiction.
The findings were intriguing. While it’s not surprising that larger rewards triggered greater dopamine release, the researchers discovered that increasing the cost of obtaining the reward also led to higher dopamine release in the striatum. In other words, there was a biochemical basis for the sunk cost fallacy.
Dr. Eshel suggests that this behavior may have an evolutionary advantage.
“In an environment with limited resources (as most are), when we typically get rewarded only after really hard work, we may need high dopamine secretion to get us to do it again,” explains Dr. Eshel. “Because dopamine reinforces previous behaviors, it may reflect sunk costs. The dopamine release we saw may enable you to pay those steep costs in the future.”
In essence, our brains may be wired to help us persevere through challenges, even when it doesn’t make logical sense. So, the next time you find yourself holding onto something despite the odds, remember that it might just be your brain’s way of ensuring your survival, albeit in a somewhat irrational manner.
The study is published in the journal Neuron.
