The bigger the bucks, the bigger the (dopamine) bang

Ahab hunting down Moby Dick. Wile E. Coyote chasing the Road Runner. Walking over hot coals. Standing in a long line for boba tea or admission to a small, overpriced clothing store. Forking up for luxury nonsense.

These activities are all examples of the overvaluation of what economists call “sunk costs”: the price you’ve already irretrievably paid in time, money, effort, suffering or any combination of them for an item, an experience or a sense of self-esteem. 

It’s a phenomenon we all recognize. It’s often irrational. But we do it. Ask me.

My ’64 stick-shift red-white-and-glacial-blue Volvo station wagon was festooned with a phalanx of three small bowling trophies for hood ornaments (I called it “the Bowlvo”). It was falling apart like a piece of overcooked chicken. (One day as I sped down Interstate 25 in Colorado, the hood flew up in my face. Another time, as I was frantically downshifting into second gear while driving home at my usual unsafe speed on a winding mountain road, the shift lever came off in my hand.)

I would have gone to the ends of the earth, or at least the end of my rope, to keep it in running condition — or just to keep it.

Strangely, we’re hardwired to value something more if we’ve put a lot of sweat equity — what we had to do to get or keep that something — into it.

“It’s not just us,” said assistant professor of psychiatry and behavioral science Neir Eshel, MD, PhD. “This has been shown in animals across the animal kingdom.”

OK — all higher animals are hardwired to make doomed decisions. Why?

Blame dopamine, that much-talked-about “do it again, do it some more” brain chemical.

There’s a difference between wanting something and liking it, Eshel said. “You can want something very, very much even though you don’t even like it very much. Or vice versa.”

A few years ago, Eshel and Stanford Medicine colleagues began conducting experiments — described in a paper published in Neuron in November 2023 — to learn more about what, if any, role dopamine secretion in the brain plays in “liking” something versus “wanting” something.

The team thought of “liking” as how much mice will consume of a reward if getting it was cost-free and “wanting” as how much that animal’s consumption is affected by the cost of getting it. 

In steps, starting at zero, the researchers increased the costs — in this case either the number of times mice had to poke their noses into a hole in a box, or the intensity of mild to moderate electric foot shocks mice had to endure — to get a reward: either sugar water or instant direct stimulation of dopamine release in two places in the brain known for their role in motivation and movement.

The researchers also varied the amounts of reward animals received for a given amount of persistence or discomfort.

Naturally, boosting the prize’s size increased dopamine release — but then again, so did raising its cost.

How does this hardwired sunk-cost hang-up make evolutionary sense? “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,” Eshel suggested.

Maybe Eshel should have tested me. I know a thing or two about sunk costs. I still miss the Bowlvo.  

Read the full story here.