Grand Theft Potato: Make Your Restrictions Real And Watch Them Work!

A study on stolen french fries turns out to explain why your doors-close deadline stopped working, and what a real restriction does instead.

Somewhere along the way most of us went out and manufactured a deadline.

You ran a doors-close-at-month-end campaign, the doors reopened the following week, and you ran the same offer again. Nobody said anything. What you didn’t see is what it cost you on the second run, because a parent who watched the deadline move once has learned something about every number you’ll ever quote them.

I ended up thinking about all of this because of a study about stealing french fries, which made me laugh out loud and then turned out to be useful.

Someone got ethics approval. Someone wrote a protocol. Someone sat in a room and said, out loud, to other adults, “What if we hired professional actors, sat them next to participants, and had the participants steal french fries off their plates?” Elsevier published it in Food Quality and Preference under the title “Stolen fries are spicier than justice.”

That’s a real title. In a real journal. With a real DOI (Skryabin, 2026). (BTW: A DOI is the permanent serial number a journal assigns a paper, so it can be found even if the web address changes). When a claim comes with one you can go read the thing yourself, which is the whole point of me putting them in.

I pulled the full text, because a forty percent effect size is usually the kind of number that gets repeated at dinner parties for a decade after the study behind it has fallen apart. This one holds up on the numbers, and its problem is somewhere else entirely.

What Skryabin actually did

The study is Valentin Skryabin, working alone, out of the Russian Medical Academy of Continuous Professional Education in Moscow (Food Quality and Preference, volume 143, 2026).

He opens by noting the folklore is everywhere. Italians say il cibo rubato ha più sapore (stolen food has more flavor). The Japanese have a word for it, nusumigui (secret eating, literally stolen-eating). Latin American dichos put it as lo prohibido es lo más sabroso (the forbidden is the tastiest). Just about every culture on earth has independently decided that stolen food tastes better, and until now nobody had checked.

He checked. One hundred twenty adults, each of whom went through all four conditions in counterbalanced order:

Legitimate. A portion of fries that’s plainly theirs. Eat them.

Gifted. A friendly confederate offers them fries. Accept and eat.

Low-risk theft. Take fries from the friendly confederate’s portion while they’re distracted.

High-risk theft. Same instruction, but the confederate is a different character entirely: closed posture, flat voice, minimal eye contact, answers in three words. The paper calls this one the Stern Confederate. Two professional actors played the roles, one male and one female, counterbalanced across participants, trained on video with feedback until they hit better than ninety-five percent script adherence. Somebody spent real money coaching a professional actor to be believably unfriendly about potatoes!

Every portion was identical. One hundred grams of fries (plus or minus two) from a single batch, fried at 180 degrees for three and a half minutes, served at 55 degrees in plain white containers. Palate cleansers between rounds. He even confirmed people ate the same NUMBER of fries in every condition, so nobody can argue the stolen ones just came in bigger handfuls.

The numbers

Ratings are on a nine-point scale. Same potato in every column.

High-risk theft beat legitimate ownership by 39.3 percent on pleasantness. Nearly half the participants (48.3 percent, or 58 of 120) gave stolen fries the maximum possible score of nine. Not one person gave a nine to fries that were legitimately theirs. The distributions don’t overlap: your own fries scored between five and seven, stolen ones between eight and nine.

The risk gradient held too. Stealing from the stern actor beat stealing from the friendly one, on the same fry, in the same room, minutes apart.

The gifted column

Being handed fries by a friendly person beat owning them, 7.03 against 6.09. Generosity is worth something! Being handed fries still lost badly to taking them, and it lost worst of all on saltiness, where gifted fries and your own fries came out statistically identical (p = 0.686). A gift changed how much people liked the fries, and saltiness didn’t budge until there was risk in it.

Skryabin put the gift condition in on purpose, as a control. He wanted to know whether the effect was about transgression or just about pleasant social contact. Warmth helps, and it changed the ratings about a point. Taking the fries changed them two and a half.

He also checked whether this was a simple halo, people liking everything more because they liked the moment more. Within each condition, the correlation between how pleasant the fries tasted and how salty they seemed was essentially zero. That doesn’t sound like a simple halo effect in which liking the moment pushes every rating up together.

The guilt test

Guilt is the explanation that suggests itself: a little moral discomfort makes pleasure sharper. Skryabin tested that directly and it didn’t explain the effect…

Guilt and enjoyment were correlated across theft trials, yes. Once he accounted for which condition a person was in, though, neither guilt nor excitement predicted enjoyment on its own. When he aggregated to one guilt score per person, the association with enjoyment vanished (not statistically reliable). His own read is that guilt tracks the risk manipulation rather than causing the pleasure.

That makes context the thing doing the work: the situation the food arrives in, not the feeling the eater has about it. Context is something you can actually build. Guilt was never the target anyway.

Where the study falls short

His participants didn’t steal anything. They were instructed to take fries by a researcher, in a room, as part of a study they’d consented to. A participant following a script isn’t breaking a social norm the way a real thief is, and he says so plainly. He calls it “role enactment or playful transgression,” and he refuses to claim it’s neurologically the same thing as real rule-breaking.

Hold that next to Mann and Ward’s 2001 forbidden-fruit work, which Skryabin himself cites. They found that being told to avoid a food raised desire for it, while choosing to avoid it did not, and that neither version produced overeating (Mann & Ward, 2001).

Skryabin has the same structure in reverse. His transgression also came from outside the participant. It was assigned, not chosen. It still changed the ratings almost two and a half points.

Which means the effect may not require sincerity at all. It seems to work when the rule comes from outside the person.

Hungrier participants showed a smaller enhancement, so this is about context and not appetite. Sixty percent of participants figured out roughly what the study was about. The sensitivity analysis split them: the effect came out the same size in people who guessed and people who didn’t. Suspicion didn’t inflate it.

More research…

Boothby, Clark and Bargh (2014), Psychological Science. Identical chocolate was judged more likeable and more flavorful when another person tasted it at the same moment, with no conversation and no comparing notes. When the chocolate was bitter, sharing made it less likeable (Boothby et al., 2014). Sharing AMPLIFIES whatever the experience already is, sweet or bitter.

Fisher and Birch (1999), American Journal of Clinical Nutrition. Restrict a child’s access to a palatable food and their behavioral response to it goes up; selection and intake rise too, though the authors are careful to bound that second part to the restricted context (Fisher & Birch, 1999).

Jansen and colleagues (2008), Appetite. They ran it with fruit. Tell a kid they can’t have the fruit and they eat more of it later, same as sweets. There was no group difference in how much the kids WANTED the fruit (Jansen et al., 2008). Restricting the fruit increased how much the kids ate without moving how much they said they wanted it. Depending on how your week is going, that’s either encouraging or slightly grim. For those of you that think kids are all perfect and good when they are born, you may reconsider.

Mann and Ward (2001), International Journal of Eating Disorders. This is the one I keep coming back to, so it’s worth the detail. The population was college women, each tested on a food she had named herself as a personal favorite, which matters because the pull was already there before the researchers touched anything. Some were told to avoid it. Others chose to avoid it. Told-to-avoid raised how much they wanted it. Chose-to-avoid did nothing. Same food, same person, same week, and the only variable was where the rule came from (Mann & Ward, 2001).

The part people skip: neither group overate. Desire changed and behavior held. A restriction from outside makes the thing louder in someone’s head without making them act on it, which is exactly why an imposed deadline can raise wanting and still leave you with the same close rate. Wanting is not buying.

Raghunathan, Naylor and Hoyer (2006), Journal of Marketing. Stop and say the lead author’s name out loud. Raghunathan. RAH-goo-NAH-thun. It takes longer to pronounce than the finding takes to explain, which tells you most of what you need to know about how academic credit gets handed out. The finding is the unhealthy equals tasty intuition: the less healthy a food is portrayed to be, the better people expect it to taste and the more they enjoy actually eating it (Raghunathan et al., 2006). Describe a brownie as indulgent and it beats the identical brownie described as wholesome.

Bratanova and colleagues (2015), Appetite. The mirror image. Food described as ethically produced tastes better, because moral satisfaction raises taste expectations before the first bite. One caveat that matters commercially: the effect held mainly for people who already endorsed the values in question (Bratanova et al., 2015). Ethics framing works on people who care about ethics… which sounds obvious until you watch someone spend a marketing budget forgetting it.

The same effect outside food

Every study above ran on something you eat. What follows are places I think the same effect runs in ordinary life, offered as extensions rather than findings…

The banned book. Somebody bans it and it sells out by the weekend. Not one word of it changed. The image about the book changed, and the change came externally to the book.

The sibling’s toy. A kid ignores a toy for a month. Another kid picks it up and suddenly both kids fight over it. Nobody added a feature to the toy. Somebody else’s interest did the whole job. (Any parent reading this just nodded.)

The other offer. A candidate you felt lukewarm about mentions they’re interviewing somewhere else, and your interest changes before you’ve learned a single new thing about them. Their résumé is identical. Their availability changed (a version of social proof)

The room you can’t get into. A seminar with a waitlist feels different from the same seminar with empty chairs, and it’s the same speaker saying the same things either way.

The number they won’t give you. Ask a vendor for pricing and get “let’s set up a call,” and the price becomes more interesting than the product. That one usually backfires, which is the point of the next paragraph.

The caution on all five comes straight from Mann and Ward. Wanting changed. Interest changed. Behavior didn’t. Every one of these may raise how much somebody wants the thing while doing nothing at all to how many of them buy it, and if the restriction turns out to be theater you’ve spent real credibility for a feeling. Test it before you build on it.

Put all of that next to Skryabin. Taste doesn’t appear to be a property of the food so much as a property of the situation. If that’s true of a POTATO, which has to be the least sophisticated object in the human diet, it’s probably true of everything you sell.

That’s six studies and one very odd paper. If you know work that cuts against any of it, or I missed something, let me know.

What this means for four groups

Parents deciding whether to enroll their kid

A parent’s read on your program comes from the situation they’re standing in when they see it.

Boothby (the finding: identical chocolate tasted better when somebody else was eating it at the same moment, and WORSE when the chocolate was bitter) applies here, and the caveat comes with it. A parent watching class alone is having a different experience from the same parent watching a 1-1 class with the instructor and child in the room. Same instructor, same information. Remember the bitter chocolate, though: shared viewing amplifies whatever is already happening on the mat. If the class is good (and you can control a 1-1 class much better than a group) and you’re all in the same room your shared great experience is amplified. If their first class is a group and it’s a mess that day (it’s harder to control), you’ve just amplified that too.

Mann and Ward (the finding: being TOLD to avoid a food raised how much people wanted it, while CHOOSING to avoid it did nothing) is the caution, and it works differently than you would guess.

A parent who sets their own limit, “we do two activities, that’s it,” picked that limit themselves. Chosen limits may hold like the Mann and Ward effect. Instead of trying to argue a parent out of something, get them to choose.

The goal was never to break their limit from the outside. The goal is to be the activity they break it for. A parent drops the limit on their own when the thing on the other side is obviously worth it to their kid, and that decision still feels like theirs, which is the only reason it sticks. That’s earned by what happens in the room: their kid’s first lesson, the instructor who knew the kid’s name, the progress they can see in three weeks. (separate article, is building the idea that the value is different from the “activities” they do).

Owners running the schools

This is the group I see getting it wrong most often, and it’s costing them.

Every owner has been told to use urgency (like a deadline). What usually happens? Externally this can work as in advertisements a deadline or limits work to increase interest and action (IF it’s believable!). Internally, you run a doors-close-at-month-end campaign for current clients, and then the doors reopen the next week and you still run the offer. Mann and Ward found that a restriction only moved desire when it came from outside the person (the finding: TOLD to avoid a food raised wanting, CHOSE to avoid it did nothing, and neither group actually overate).

The version that works is boring and REAL, and in a school it is almost never about seats. You want more students, always, and every parent knows it. A cap you invented on your own floor is the least believable thing you own.

What IS true in your school, and true whether anybody buys or not:

The standard. Nobody tests until they can do the material. That restriction is real, you enforce it every cycle, and it is the entire reason the belt is worth anything. A parent who hears “he isn’t ready yet, here’s what he’s working on” is watching you turn down money in front of them.

The calendar. The beginner cycle starts when it starts. The testing cycle is 8 weeks (or whatever you designate… my school calls them “semesters”) and it does not bend around one family’s schedule. That date is real because the whole school runs on it.

The instructors’ hours. Private lessons are not available unless you offer one. Your time and your instructors’ time is valuable.

The room, when it’s actually the room. A seminar, a camp, a guest instructor weekend. Those have a real number attached because the venue has one.

Every one of those is believable to a parent asking “is that really true?”.

Most owners I talk to have the decorative kind and believe they have the real kind. The test is one question, and it isn’t about enrollment: would you hold this if it cost you a sale in front of you?

You already know the answer on testing. You have held a kid back from a test, with the parent standing right there, and you did it because the standard is the product. That’s what a true restriction feels like from the inside. Anything you would drop for one good family on a slow month was fake and it’d feel that way.

The same mistake runs in the other direction too. In Scarcity Is a Lousy Strategist I went through what happens when an owner accepts a scarcity claim about his own market. Same habit, pointed inward instead of at the customer, and it costs about the same.

The Gifted column ran with no scarcity in it at all, and it still beat ownership by nearly a full point on a nine-point scale. Free trial classes, a genuinely good first lesson (that you can control), the instructor who hands a kid something on the way out. All of that works.

Authors publishing a book…

Authors have a Raghunathan problem (not just pronouncing the name), and it shows up on the price.

Raghunathan (the finding: the less healthy a food was described to be, the better people expected it to taste and the more they enjoyed eating it) is really a finding about what a description does to an experience before it starts. Price (higher could be considered “worse”) is a variable your book has.

Price your book at $2.99 and you have told the reader what to expect before they open it. They read it that way. The same manuscript at $24.99 in hardcover gets read as a serious book by a serious person, and that reader arrives ready to find it useful. Nothing inside the file changed. The situation they read it inside did.

There are lots of different pricing strategies so lower may be best in some scenarios, however if you’re shooting for higher value and authority this effect is important. I’d rather sell fewer copies of a book people treat as valuable than more copies of one they filed under “cheap download I’ll get to.” Another way this effect works is if you send a hardcopy of a book to a client rather than email a “free download”, the physical book, mailed to them, has more value.

Financial professionals and business owners

Bratanova (the finding: food described as ethically produced actually tasted better to people, because feeling good about the purchase raised their expectations before the first bite) is yours, and here’s the version I’d put in front of a client.

Two index funds. Same fee, same ten-year return and risk profile. One arrives as a line on a spreadsheet. The other arrives with “I screened these against what you told me you care about” and an explanation of the difference. The client picks the second one and reports being happier with it a year later, on identical performance.

You’ve probably called that irrational. It isn’t. Their experience of holding that fund really was better, because how it arrived changed how it felt to own. Same instrument, different situation, exactly like the potato.

Here’s a thought for you: a client who feels good about why they own something stops calling you in a bad quarter. The behavior you’re trying to produce is that they don’t panic-sell, and framing does more work on that than another page of performance history.

The caveat matters though… Bratanova’s effect held mainly for people who already held the relevant values (oh and it was a food study so this is my extrapolation). Aim a values story at a client who never mentioned values and you’ve sold them something they didn’t ask for, which is worse than the spreadsheet (and may not agree with their values). Find out what they actually care about first, then tell them the truth about it.

Where the joke stops

In clinical mental health work, manufactured scarcity isn’t a tactic. It can be a harm. Someone deciding whether to get help isn’t a prospect with a wanting problem, and limited-spots language aimed at that decision is indefensible no matter what the conversion data says. It’s great to be a high paid therapist or mental health professional, but if someone needs help ethics suggest you provide options like referrals.

What to do with this

Pick one restriction in your school and make it TRUE. Not a new one. A true one. The testing standard you already enforce. The cycle date the whole school runs on. The deadline you’d honor if your best family called the day after. Real restriction changes wanting. Decorative restriction costs you credibility on the second run.

Then improve one situation without touching the product. Where parents sit. How a proposal arrives. What a family sees in the first ten minutes. Because we’re extrapolating for fun here, Skryabin changed a potato 2.39 points on a nine-point scale (6.09 to 8.48) without changing one thing about the potato, just the circumstance. Maybe you can find your version of that.

Then go count. Write down every deadline, cap and window you’ve put in front of a family in the last ninety days, and mark each one with a yes or a no on a single question: would you hold this if it cost you a sale standing in front of you? The no’s are the ones teaching your parents to wait.

One last note, and it’s the author’s own. In his discussion of future research, Skryabin suggests testing foods more commonly associated with opportunistic theft and singles out cheese, which he notes is widely reported as the world’s most-stolen food. That line is sitting in a peer-reviewed journal right now waiting for somebody to build a career on it. If someone eventually publishes on stolen cheese, I want it on record that I saw it coming!

In the meantime, if someone reaches across the table and takes a fry off your plate, let them have it. They’re going to enjoy it about forty percent more than you would have, and now you know why… and then steal their dessert!

References

A version of this article first appeared at mastermoody.com.