William M. Briggs

Statistician to the Stars!

Shocking New Research: Hunger Motivates Eating

Never shop when you're hungry.

Never shop when you’re hungry.

Ladies and gentlemen, the opening line of the peer-reviewed paper “Hunger promotes acquisition of nonfood objects” appearing in the (once) venerable organ Proceedings of the National Academy of Science, by Alison Jing Xu, Norbert Schwarz, and Robert S. Wyer (HT to John Cook for bringing this to our attention):

Hunger can drive people’s responses to food.

Who knew?

Not only can hunger drive people’s responses to food, “Hunger motivates people to consume food, for which finding and acquiring food is a prerequisite.”

Site managers for fast-food franchises and grocery stores take note.

Anyway, that isn’t the real research. This is: “We test whether the acquisition component spills over to nonfood objects: Are hungry people more likely to acquire objects that cannot satisfy their hunger?”

Science did not know the response to this puzzling query before the valiant efforts of our trio. I’ll reveal the shocking answer below, but first it’s important for you to comprehend how important the scientific enterprise is. Without science, and without massive government control of and spending on research—this grant was funded by the “Social Sciences and Humanities Research Council of Canada”—humanity would be left in the dark on such monumental questions like whether hungry people are more likely to acquire objects that cannot satisfy their hunger.

As is obvious, it would take a ton of painstaking research to answer the question. That’s what happened here. Our trio did not just do one laboratory and field study, nor only two laboratory and field studies, and not even three laboratory and field studies…but five—count ’em! FIVE—laboratory and field studies.

Now in preparing these arduous studies, our trio first reviewed previous studies on similar topics, where they learned hunger “can increase men’s preference for heavier women, who presumably have richer calorie resources”.

(This reminds me that there is one cannibal joke in this must-have new book: Uncertainty: The Soul of Modeling, Probability & Statistics.)

A word of caution: “The predicted increase in acquisition of nonfood items [drive by hunger] is not necessarily accompanied by increased liking of these items.” This is because there is a “distinction between liking and wanting” and that is because liking and wanting are “processed by different neural substrates…For example, being prevented from obtaining a desired outcome can increase the desire to obtain the outcome while reducing its attractiveness.”

Insert pop-culture reference here: Two Out of Three Ain’t Bad.

Now to the meatiness: experiment one.

Study 1 examined whether hunger increases the cognitive accessibility of concepts related to acquisition. Native English speakers (n = 69) performed a word identification task (15). They saw 22 words and 22 nonwords flashing one at a time on a computer screen at a rate of 50 ms, followed by a series of pound (#) signs. Words and nonwords appeared alternately. In each case, participants typed in the word they saw. If they could not identify what they saw, they could either make a guess or type in “X.” Of the 22 words, nine were semantically related to acquisition (e.g., acquire, want, obtain, gain), four were hunger-related words (e.g., hunger, starve, appetite, famine), and the rest were control words (e.g., speak, close, floor, symbol). Upon completion of the task, participants reported how hungry they were along a scale from 0 (not at all) to 10 (very). The likelihood of correctly identifying hunger-related words increased significantly with self-reported hunger (b = 0.024, SE = 0.012, t = 1.99, P = 0.05)…

There you have it. A wee p-value confirms hungriness and hungry-grammar are matched pairs.

So it went for the other four. Are you ready at last for the stunning conclusion? Yes?

Hunger is one of the most basic and primitive drives of human behavior…Even in affluent societies, episodes of mild hunger are not uncommon…[because] millions of Americans are dieters who deliberately deprive themselves of calories every day…The present findings suggest that such behaviors [as dieting] are likely to lead to unplanned purchases in nonfood domains.


That’s not all, gentlemen and ladies. “Future research” is needed! What is yet a complete mystery is that if a hungry person buys more than food, does a person who buys something besides food also buy non-food items? “Much as hunger gave rise to the acquisition of nonfood items in the present studies, a desire to acquire nonfood items may lead to the unplanned acquisition of food when the opportunity arises.”

Nobody knows! This is your big chance to be part of the famed Scientific Method. Get those scales out and research, research, research!


  1. My university added a food room (it must have a fancy name, but I can’t think of it right now) to the library a few years ago. No one yet has quantified the correlation between the hunger for knowledge and the hunger for a mocha latte and bagel. Somebody should alert the social scientists that there is a rich vein of research ore right under their noses. I’m sure they can figure out how to get computer word flashing into the investigation.

  2. Not sure PNAS was a part of science. I’ll take your word for it. I find that the use of the words “truth”, “real”, “fact”, “science” are often used to induce a very false sense of security into the reader. A study is in order when I find a publisher that has none of the problematic words in their journal’s name. (Okay, I’m pretty sure National Enquirer would publish it, but that’s not really much of an audience.)

    I’m not sure how being hungry makes one buy more non-food items. When I’m hungry and out buying groceries, I may pick up a couple of extra items on the route to what I need to purchase, but I don’t drive the cart around looking for items to buy. I buy food and go home and eat!

    Gary: Perhaps the room could also serve as as study in the housekeeping habits of students—was there a huge influx of mice about the same time food was introduced and do the books have more food stains now?

  3. Richard Spacek

    July 15, 2016 at 9:19 am

    One of the better observations in Postman’s very uneven Technopoly was that we have come to accept the modern practice of having experts conduct research into the bleedin’ obvious. His first example was a study that showed people fear death.

  4. Did I read the excerpt right? The researcher used word recognition and recall as a proxy for actual behavior. What am I missing?

  5. Ye Olde Statistician

    July 15, 2016 at 11:02 am

    there is a “distinction between liking and wanting” and that is because liking and wanting are “processed by different neural substrates

    Or do wet streets cause rain? Perhaps different neural substrates are used because liking and wanting are different? This needs more research.

    When I’m hungry and out buying groceries, I may pick up a couple of extra items on the route to what I need to purchase

    But the study does not appear to have studied such actual behavior, only correlations between correctly spelling words thought to be in certain classes and reported degrees of hunger afterward.

    Is someone who reports a hunger level of 4 really twice as hungry as someone who reports a hunger level of 2? If not, it is not a ratio scale and means and s.d. cannot be drawn. If Adam reports he is 4-hungry and Betsy reports she is 4-hungry are they both equally hungry? If not, it’s not a scale at all, but an attempt to quantify something unquantifiable.

    Reading this post has made me hungry.

  6. LOL! I wonder if they controlled for pot! They say you should never go shopping when you’re stoned, because between the munchies and the impulse items, you never know what you’ll come home with!


  7. “Without science, … humanity would be left in the dark on … questions like whether hungry people are more likely to acquire objects that cannot satisfy their hunger. …This is your big chance to be part of the famed Scientific Method.”

    Here Briggs goes again…extrapolating from one oddball & questionably performed study to bash an entire discipline — science.

    Fortunately, credible statisticians, and associated organizations, can & do recognize the issues with p-value — without coming close to making the logical fallacy [sweeping generalization] that if some researcher mis-applies statistics to a silly study topic that that individual’s conduct is somehow evidence that the entire discipline of science itself is bad.

    Here’s the ASA’s recent position on the matter:

    They didn’t resort to the use of sarcasm or sweeping generalizations … nor the involvement of Briggs [despite his credible focus on p-value abuses] … could there be something to that correlation…

    Consider the conclusion from the ASA’s statement on p-values:

    “Good statistical practice, as an essential component of good scientific practice, emphasizes principles of good study design and conduct, a variety of numerical and graphical summaries of data, understanding of the phenomenon under study, interpretation of results in context, complete reporting and proper logical and quantitative understanding of what data summaries mean. No single index should substitute for scientific reasoning.”

    The divergences between the ASA view & Briggs on study conduct is left to the reader to note & ponder.

  8. YOS: Me too—I’m going to go eat! As for the lack of data and subjective scale, I guess that’s the “new” science.

    Ken: Journals keep publishing these things. I don’t see science as objecting much or they’d reject such worthless studies. It’s not just one study or one journal.

  9. Ye Olde Statistician

    July 15, 2016 at 5:01 pm

    extrapolating from one oddball & questionably performed study to bash an entire discipline — science.

    Actually, he’s only bashing social “science.” Physics and chemistry are still above the fray, although there is a movement even there to accept theories based on their mathematical elegance rather than on empirical data.

    Consider the recent and ongoing food-fight called the Replication Wars. Some nasty, hurtful psychologists tried to replicate a couple dozen “significant” studies and could not do so. Worse, they published their failure to do so, leading one falsified researcher to complain about “replication bullies.” One imagines the researcher breaking into tears and making for a “safe space.”

    In 2005, epidemiologist John Ioannidis published a bombshell of a paper called “Why most published research findings are false”. In it he catalogued a litany of failures that undermine the reliability of science in general. His analysis concluded that at least half, and possibly a large majority, of published research is wrong.

    More recently he has written about an “Epidemic of False Claims.”
    Elsewhere, we read:

    “A few years ago, scientists at the Thousand Oaks biotech firm Amgen set out to double-check the results of 53 landmark papers in their fields of cancer research and blood biology.
    The idea was to make sure that research on which Amgen was spending millions of development dollars still held up. They figured that a few of the studies would fail the test — that the original results couldn’t be reproduced because the findings were especially novel or described fresh therapeutic approaches.
    But what they found was startling: Of the 53 landmark papers, only six could be proved valid.”

    So we can conclude that Ioannidis was a starry-eyed optimist. Nor were Amgen’s results unique.

    It’s not just the p-value problem and the confusion of correlation with causation.

    [T]he more important flaw in the publication model is that the drive to land a paper in a top journal — Nature and Science lead the list — encourages researchers to hype their results, especially in the life sciences. Peer review, in which a paper is checked out by eminent scientists before publication, isn’t a safeguard. Eisen says the unpaid reviewers seldom have the time or inclination to examine a study enough to unearth errors or flaws.

    And there is always http://retractionwatch.com/

    Dr. Briggs performs a service by focusing on the more ludicrous cases.

  10. Unfortunately, Ken falls prey to a little-known fallacy called Completely Missing The Point when he writes that “p-value abuses” are Matt’s focus. That’s like saying that all good phrenologists already recognize “phrenology abuses” if they come upon them, and need not resort to Matt’s intemperate, sarcastic, and overblown rhetoric to make such a well-understood point.

    The recent statement by the APA (American Phrenological Association) makes this absolutely clear:

    “Good phrenological practice, as an essential component of good scientific practice, emphasizes all the good things we think are associated with science, without in any way pointing out the obvious fact that none of those things have anything to do with phrenology per se. Phrenology is therefore sound and good and worthwhile, and so are our phoney-baloney jobs.”

  11. Got my copy of Uncertainty on July 15th. Thanks.

  12. JohnK: Great pointing out of a little known fallacy!!

  13. I will add the “little-known fallacy called Completely Missing The Point” to my list.

  14. I. J. Kennedy

    July 17, 2016 at 1:41 am

    What on Earth are you going on about? The part about hunger driving food acquisition was just a single introductory sentence, a set up to the main point: that hunger also triggers non-food acquisition.

  15. “Hunger is assumed to motivate eating, which satisfies the caloric needs underlying the motivation.”
    So the entire study is based upon an assumption that is further extrapolated to non-food items. How is that better?

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