About misinformation, behavioral economics & The Mystery of the Blue Mussel

There was something fishy about the case. Any private investigator could see the ocean-sized holes in the story. Yet, no one said it out loud.

Did foodies willingly delude themselves?

Would rational, reasonable people knowingly take a material loss to maintain a fairytale?

Were 90% of cookbooks sharing misinformation?

If you suspect behavioral economics and shellfish to be boring, you’re wrong.

I will prove it to you with carefully gathered clues and evidence.

Because after six years of investigating The Mystery of the Blue Mussel, I can guarantee it’s anything but an open-and-shut case.

And if you think I’ve overcooked the puns to widen the net for people who aren’t into behavioral science…

Well, okay, that might be true.

But if you read on and don’t clam up, I promise you a pearl of wisdom that may leave you shell-shocked…

Recipe for Disaster: The Myth & the Mystery

The case had been cold for decades. Until now. Why did it suddenly show up on my desk? Had the nerds in behavioral science found something new? And if so, how could I turn it into an entertaining blog post for my readers?

The myth about blue mussels is very simple and pretty well-known.

“The ones that don’t open when you cook them are bad and can make you sick. Throw them away.”

If you eat blue mussels, you’ve probably heard it said.

It’s been printed in cookbooks for decades.

And it’s not true at all.

The first mention of the mussel myth appeared in Fish Book by Jane Grigson in 1973.

Until then, it had never been seen in print.

By the 1980s, the myth had spread to 30% of cookbooks and by the 1990s to more than 90%, cementing the myth as common culinary wisdom.

Since then, several studies have refuted the myth and proven that unopened mussels are no more likely to be bad than open ones. After cooking, the only way you can tell is by the texture of the meat (source: ABC Science).

Now, why is this relevant to advertising?

The popularity of blue mussels grew along with the myth.

After WW2, increased trade in Europe meant increased exchange of gastronomic cultures — but not all foods were created equally. Blue mussels looked weird, smelled funny, and came with a rumored risk of food poisoning.

I’d argue that the best PR and advertising the blue mussel ever got was the myth that the bad ones don’t open.

From Z. Ozolina Mussel Farming and Its Potential in the Baltic Sea

Imagine yourself in the 1980s.

You’re at a dinner party with your yuppie friends (okay, with your goth-rock friends, I know my readers) trying a strange new food. It’s exotic and exciting — but there’s a small, irrational chance it’ll make you very sick.

Believing you can perform an act to genuinely minimize risk is powerful. It gives you a sense of control over the strange, alien-looking object.

Not only is it good advice in a cookbook to relieve anxiety in the reader and remove a mental barrier on the user journey, it’s also social currency as a well-placed anecdote at the dinner party. Now your friends can have that good feeling of control too — with you to thank for it.

By pairing a story with a symbolic act to ease anxiety, new audiences found the courage to try the strange food — even though the myth had no basis in reality.

Misinformation spreads faster than truth because it appeals to our desire for easy solutions and confirmation bias (according to a study on the site formerly known as Twitter).

And sacrificing food is one of our oldest rituals for believing in unscientific nonsense.

Steam Rises and the Plot Thickens: Fact-Resistant Superstition

The steam from the mussels looked like smoke from a cigarette. The clues were just as elusive. From its first mention, the mussel myth had spread like wildfire. But what was keeping it alive?

While the mussel myth is easy to understand, its persistence has been a mystery.

Since the late 1990s, a movement to debunk the myth has risen — but barely made a dent.

Biologist and mussel expert Nick Ruello has led an admirable crusade against mussel misinformation… and still, almost no one knows.

In my own (admittedly unscientific) research of asking 10 people, eight had heard about the myth, but only two had heard it debunked (both from me on previous occasions).

The factual truth about mussels holds obvious value that should make it worth sharing:

Regain lost material value — you literally get more food.
Lay misinformation to rest — make society smarter.
Appear knowledgeable — gain social status.

If we dissect the nature of fun facts to bring up at dinner parties, those are pretty good qualities.

I bang the drum every time I eat mussels with friends (annoyingly so, preachingly even), and still, every moules frites-eating, city-dwelling hipster I know throws away unopened mussels.

None of them throw salt over their shoulder when they see a black cat.

They’re civilized people, not old-timey fishermen in remote villages where news never travels.

Then why the stubborn superstition?

The Usual Suspects: The Brain & the Biases

With solid science to prove the fallacies, why had no one studied why the myth prevailed? Why had not a single soul in academia or on the internet tried to explain why highly educated, well-informed foodies remained trapped in superstition? Was Big Clam pulling the strings behind the scenes?

For most mussel eaters, the myth is old news, assumed true simply because it’s been in cookbooks for decades.

The factual truth is comparatively new and fresh, provides a chance to combat misinformation, and puts more food on your plate.

Then why hasn’t the pendulum swung yet?

As far as I’ve been able to find, no one has studied the reason behind the longevity of the myth.

If that is truly the case, I hope this can be my humble contribution to its debunking.

Because the answer might just be the trivial fact that the human brain prefers agency over utility.

If classical economics were right, humans should always seek to maximize utility and material value. As a result, the mussel myth would die as consumers became informed because rational agents would always prioritize material gains over irrational fairytales. The truth and its tangible value should easily defeat the myth.

Well, classical and neoclassical economics are wrong.

They’re reductive math models trying to make formulas about social studies.

Dance about architecture!

Traditional economics explains how reasonable people are supposed to behave, behavioral economics explains why they don’t.

Humans aren’t rational actors, we’re anxious apes.

We didn’t evolve to make optimal decisions under perfect conditions — but to make the least disastrous choices in the chaos of real life.

The ancestors who didn’t die young from doing something stupid had more time to procreate… and as a consequence, we all come from a long line of risk-averse survivors.

From Daniel Kahneman, Thinking Fast and Slow

This may sound like evolutionary psychology for dummies but it’s also the solution to the Mystery of the Blue Mussel.

Loss aversion counts double the promise of gain, and if you risk losing several days to food poisoning, gaining a handful of unopened mussels just doesn’t matter. Better to be safe than sorry.

Furthermore, it’s much easier to make a single System 2 choice at the beginning of dinner and then coast through the meal on System 1, than to stop and think critically about the looks and texture of each individual mussel.

Fear and the basic human preference for indecision make us play make-belief with comfortable myths.

What’s pulling the strings is the primitive brain, clawing at an illusion of control.

Spiritual Shell Games: Sacrifice & Ritual

If a private investigator can’t even trust his own brain, what good is he? The thoughts were spinning in my head, flashes of light exploding across my eyes. Was it madness? Or a higher calling? God?

Every major religion has sacrificed food to the gods.

The Bible contains multiple detailed descriptions of how to kill animals and give offering.

Food sacrifice is one of our most basic ritual acts across cultures.

In a way, the IKEA Effect also comes from food sacrifice.

The IKEA effect is the cognitive bias that explains why we value products or experiences more when we contribute to them.

Originally, it got known as the Betty Crocker Effect when the American food brand struggled to introduce the revolutionary concept of shake-and-bake in the 1960s.

“Just add water” sounded too easy and took away the symbolic value of baking for your loved ones.

The American housewives wanted none of it!

Only when a copywriter changed the packaging to say “add one egg” did the strange new concept take off.

When Betty Crocker asked the customer to sacrifice a bit of convenience — add one egg, a spoonful of effort, a touch of care — the perspective changed and what looked like a shell game became believable magic.

When you throw away unopened mussels, it mirrors ancient rituals of sacrificing food to avoid damnation; it gives you a myth to tell yourself so you can believe you don’t get food poisoning... But really, it’s just the Betty Crocker effect.

It’s the same reason that the cheap furniture you build yourself has an aura that makes it 63% more valuable.

The emotional investment in ritual and sacrifice is a fundamental human gesture where we give up resources and logic to be spellbound by storytelling and sunk cost fallacy.

Irrational Luxury: The Femme Fatale of Economics

I was in too deep. She had always been too good to be true. But now, she was volatile, high-maintenance, and could break down at any moment. By “she” I mean the blood-red Ferrari parked outside my office; a gift from Big Clam to shut me up…

Sacrifice is always powerful. And the more you give up, the more it comes to mean.

It’s why cults will make you cut contact, move to the compound, and drink the Kool-Aid. The more absurd the belief is, the more ridiculous the sacrifice must be.

Luxury brands know this better than most.

Just like cults may seem absurd to outsiders, luxury goods defy logic to those who haven’t bought into the symbolic value of the brand.

From Dollet & Diaz Supply Chain Orchestration for the Luxury Alcoholic Beverage Sector

A Rolex will lose a second or two every year. A digital Seico won’t. A Ferrari is an uncomfortable piece of megalomania with historically bad brakes and poor customer service. Yet with undeniable status.

Luxury products offer less measurable value than their premium competitors and that’s the paradoxical reason they’re worth more.

Veblen goods* have always been a sore spot for classical economists because luxury breaks the law of supply and demand. Luxury brands were working from psychological insights about sacrifice and storytelling long before behavioral economics came along to explain them.

Customers sacrifice ridiculous amounts of money and effort to get subjective value from sometimes objectively subpar products.

How much does it cost to give up reason?

Just enough to make it hurt.

That’s why it works.

Because even if the product is subpar, the experience is elevated through ritual.

Luxury must defy logic and reason because if it makes sense, it’s not magical. Magic can’t make sense.

Over the past few years, luxury fruit brands have emerged with product portfolios including white strawberries from Japan and red pineapples — the latter costing as much as $400 for a single pineapple. Is it ridiculous? Or is it magic?

Wine tastes better if you think it costs more, studies show.

Price and framing play a trick on you and make the experience more enjoyable. And if the trick works… isn’t it a kind of magic?

Once you’ve sacrificed enough to feel the sting, your faith in the experience is forced and you’re more likely to become a brand believer. You have made an offering to the ritual and created an aura around it.

Whether it’s food, furniture, or Ferraris, irrational sacrifice doesn’t just create subjective value, it enforces it.

*Veblen goods — named after economist Thorstein Veblen — are products whose value increases because of their high price, not despite it. They get their status from being scarce, expensive, and often impractical.

Closing the Case: Food for Thought

Objective value didn’t exist.

Facts didn’t matter if they took away control without offering something better.

That’s why the truth about blue mussels hadn’t beaten the myth; humans will sacrifice both food and facts to maintain an illusion of control.

People don’t want to be lied to but they’ll lie to themselves to feel in charge of their own destiny.

If you’re marketing a product with a perceived risk, adding an element of sacrifice or unnecessary user interaction might help negate (or at least distract from) the risk.

Like when Wash & Go in the 1980s and 90s suffered a rumor that their product had made someone lose their hair. The IKEA effect suggests they could have launched a two-component shampoo to give back their customers a feeling of control with a ritual to perform. Instead, “Wash & Go Bald” was a running joke for decades.

We all like to think we hold beliefs and act accordingly.

But in reality, we act first and then invent beliefs to justify ourselves.

We are not a rational species, we’re post-rational.

The brain mistakes sacrifice for value to avoid regret, creating a feedback loop that binds us to habits, myths and brands alike.

Sacrifice is powerful and rituals have meaning.

Help your audience feel in control.

Be a detective for the truth and know when cognitive biases are getting in the way.

If your marketing strategy feels like an open-and-shut case, there’s a risk you’re simply maintaining myths to preserve your own biases and illusions.

Behind all good advertising is an investigation of human behavior.

The Mystery of the Blue Mussel might be solved, but the case of the human ape — and why we do what we do — remains wide open.

What Fishy Psychology Taught Me About Advertising