How chocolate can help you lose weight

June 6, 2015

Can you indulge your sweet tooth and lose weight at the same time? If it’s chocolate you crave, then the answer seems to be: yes. That is the surprising conclusion of a study by German researchers published this week in the International Archives of Medicine.

Confusion reigns in the diet world, with conflicting recommendations for diets that range from high-protein to low-carbohydrate and even high-fat. According to many nutrition researchers, the problem is that these tools are too blunt. “What is important is the specific combination of foods in your diet,” says lead author Johannes Bohannon, research director of the nonprofit Institute of Diet and Health. “Just lowering the proportion of carbohydrates is not a reliable weight loss intervention because it has different physiological effect depending on the bioactive compounds in your diet.”

Chocolate is a rich source of bioactive compounds, particularly a group of molecules called flavonoids, plant compounds associated with several positive health impacts. But teasing out the possible effects of such compounds in your diet, and how it may interact with various diet interventions, is rarely studied. It could be that simply consuming chocolate in combination with dietary interventions has no effect, or it could make such diets even more effective in the right dose.

To test the idea, the researchers divided volunteer human subjects aged 19 to 67 into three groups: One group followed a strict low-carbohydrate diet, another group followed the low-carbohydrate diet and also consumed 42 grams of dark (81%) chocolate per day, and a control group followed their status quo diet. Besides tracking their body weight and measuring blood chemistry before, during, and after the intervention, subjects filled out questionnaires to assess sleep quality and subjective well-being, a key predictor of dietary compliance.

As predicted, the low-carb group lost weight compared to the control. But surprisingly, the low-carb plus chocolate group lost 10% more weight. Not only that, but the weight loss persisted, compared to the low-carb group which saw a return of the weight after 3 weeks—a classic problem in dietary interventions known as the “yo-yo effect”. The chocolate group also reported better sleep and well-being, and their blood cholesterol levels were significantly reduced.

“To our surprise, the effect of chocolate is real,” says Bohannon. “It is not enough to just consume chocolate, but in combination with exercise and reduction in carbohydrates, our data indicate that chocolate can be a weight loss accelerator.”The researchers suggest that high-cocoa chocolate has the potential to enhance other diets as well. “The best part about this discovery,” says Bohannon, “is that you can buy chocolate everywhere, cheaply and without having to believe diet gurus or purchase expensive nutrition products over the Internet.”

Press release from The Institute of Diet and Health


Don’t you just love this press release? It is just the kind of thing to get some newspaper editors salivating and social media users sharing online. If it sounds too good to be true, I’m afraid it actually is. The chocolate-helps-you-lose-weight hoax was the brainchild of German television reporter Peter Onneken who pitched the idea to American journalist John Bohannen. They set out to prove how easy it was to get a dodgy scientific study published. In fact, the study did take place, but as we shall see, it was deliberately shorn of any scientific value.

Some people may find this unethical, but elaborate hoaxes are a tradition among sceptics. In previous posts I have mentioned how physicist Alan Sokal was able to get a bullshit article, Transgressing the Boundaries: Towards a Transformative Hermeneutics of Quantum Gravity, published in an American cultural-studies discussion journal, Social Text. The spoof piece was made up of ideas and quotations from various postmodernist philosophers and full of mathematical absurdities, which the editors failed to spot. I have also featured the magician James Randi, who coached stage performer José Alvarez to pretend he was channelling a two-thousand-year-old spirit named “Carlos”. And who can forget science writer Dr. Ben Goldacre’s dead cat, Henrietta, who became a certified member of the American Association of Nutritional Consultants after Goldacre paid $60 to the Clayton College of Natural Health?

For the experiment Bohannon claimed to be Johannes Bohannon, Ph.D., a health researcher and lead author of the study. Onneken and his collaborator, Diana Löbl handled the logistics. They had a few thousand Euros to recruit research subjects on Facebook. They also required the services of Gunter Frank, a German doctor responsible for running the study, and Alex Droste-Haars, a financial analyst, to massage the data. The study was intentionally flawed with a ridiculously small sample size, measuring 18 variables (weight, sleep quality, and cholesterol levels among others) that naturally fluctuate in participants. The 16 subjects (5 men and 11 women, aged between 9 and 67) chosen were from Frankfurt, and were paid €150 to go on a diet for 3 weeks. They were divided into three groups – one was a low-carb. Another was low-carb plus chocolate a bar every day, and the final one was a control group who were told to follow their normal diet. The participants had to weigh themselves every day for the three weeks, and the researchers also took blood tests, measuring all the variables you can measure from a drop of blood. The subjects also filled out surveys about their sleep quality and well-being and physical complaints.

By the end of the study they had a mountain of data. The control group’s average body weight fluctuated up and down around zero. Both of the treatment groups lost an average of around 2.5 kilos over the course of the study. But the people on the low-carb diet plus chocolate lost weight 10% faster, a statistically significant result. Moreover, the chocolate group had better cholesterol results and higher scores on the well-being survey.

The amount of data was of course one of the problems with the study. If you have a small number of people and a large number of variables that you’re testing for, you’re more or less guaranteed to find something that will appear to be statistically significant. It is a tried-and-tested recipe for false positives. And If you don’t say ahead of time what exactly you’re looking for, then you can just pick up wherever random result you do get and claim that you have made an important discovery. In this case what varied was the speed at which the participants lost weigh, but the result could have just as easily been that chocolate improves sleep quality or lowers blood pressure or cholesterol levels.

Now Bohannon and Onneken wanted to share their “scientific breakthrough” with the world. They needed to get their study published ASAP. As it was such patently bad science, they had to avoid any kind of peer review. They had the perfect solution. For €600 Euros published it in their premier journal, the International Archives of Medicine, an open access medical journal.

What happened then? It did get picked by the German newspaper Bild and Britain’s the Daily Star. It also made it on to Cosmopolitan’s German website and both the German and Indian websites of Huffington Post. On the other hand none of Britain’s broadsheets were fooled. Nor was the New York Times. The story also failed to appear on a major national network. However, I’m sure that this kind of material does frequently get through. Just go to Ben Goldacre’s website.

Curiously, the Facebook page for the International Archives of Medicine featured a statement from Carlos Vazquez the journal’s CEO, claiming the paper was published by mistake and was only live for hours:

Disclaimer: Weeks ago a manuscript that was being reviewed in the journal “Chocolate with High Cocoa Content as a Weight-Loss Accelerator” appeared as published by mistake. Indeed that manuscript was finally rejected, although it went online for some hours. We are sorry for the inconvenience. We are taking measures to avoid this kind of mistakes happens [sic] again.

This appears to be a terminological inexactitude as the paper appears appears to have been on a number of weeks. What’s more there is apparently this email from Vazquez:

I’m contacting to let you know your manuscript “Chocolate with High Cocoa Content as a Weight-Loss Accelerator” has been pointed by our editors as an outstanding manuscript and could be accepted directly in our premier journal *International Archives of Medicine.

Bohannen’s hoax raises questions about scientific experiments. This has been an ongoing theme in this blog. The abovementioned Ben Goldacre is a trenchant critic of such practices by the pharmaceutical industry. In “Missing Data“, the first chapter of Bad Pharma he shows the tricks employed by Big Pharma so that clinical trials will reach conclusions favourable to the drug company. He describes publication bias, in which only tests with important results are published. If a lot of tests with inconclusive results are ignored, this will skew the results. If the trial seems to be producing negative data, it may be stopped prematurely and the results not published, or if it is producing positive data it may be stopped early so that longer-term effects are not examined.

Ultimately we have to look at the role of the journalists. If you’re reporting on a scientific study, you need to actually look at the paper. You need to talk to a source with real scientific expertise. They need to actually interview the people behind the studies, and they should seek independent researchers’ opinions. And a healthy dose of scepticism wouldn’t go amiss.

The point of tipping

May 10, 2015

I’ve seen So-and-So with another man’s wife,

I’ve seen High Society eat with its knife,

I’ve heard the worst claret pronounced “nonpareil,”

I’ve heard the best Roquefort condemned for its “smell”. . . .

I’ve bowed and obeyed, and I’ve always agreed

My business to serve is, and not to take heed;

A quarter will cause me to doubt my own mind,

And after a half I am deaf, dumb, and blind.

A poem in the voice of a waiter from the turn of the last century


Tipping is a confusing, and paradoxical behaviour. We tip some people who provide services but not others. In the U.S. 31 different service professions are tipped, whereas In Japan this figure is four, and in Iceland it is zero. In Japan tipping is seen as an insult. It is assumed that we tip in order to encourage good service but we leave one only after the service has been given, when it is too late to change it, often to people who will never serve us again. Why do we engage in this apparently illogical behaviour?

The majority of historians agree that tipping has its origins in an aristocratic custom which began in England early in the 17th century. On departing visitors were expected to leave an amount of money, known as a vail, to the servants. This practice then spread to coffee houses, then to other service providers and it was eventually exported around the world.

What is less clear is the origin of the word. Loyal readers of my blog will know that I am sceptical of folk etymology. There are a number of words which are said to have begun as acronyms Examples of this dodgy lexicography include posh (Port Out Starboard Home), cop (Constable on Patrol),  golf (Gentlemen Only Ladies Forbidden) and shit (Ship High in Transit) and the classic fuck (Fornicating Under Consent of King). The origin of tip as being To Insure Promptness is surely another case of this. The Latin word stips, which means a gift, is one possible source.

If there is country where tipping is deeply engrained, it is surely the United States. One estimate, which is from a years ago is that Americans tip for the value of approximately $40 billion. To put this in context the budget for NASA is under $20 billion. The fact that tipping is so prevalent in the States is somewhat paradoxical. Many see it as un-American, an undemocratic throwback to Europe and its class-riven society. Indeed, there has always been opposition to the practice. In 1904 William R Scott formed the Anti-Tipping Society of America, whose members had to take an Alcoholics Anonymous-style pledge to not tip anyone for 12 months. In 1912 another organisation, the Society for the Prevention of Useless Giving, joined the fray. There were also polemics written. In “The Itching Palm: A Study of the Habit of Tipping in America”, Rufus Scott, railed against tipping and the aristocratic worldview it represented. It was what they had left Europe to escape from. These campaigns bore some fruit. In the 1910s Arkansas, Georgia, Iowa, Mississippi, South Carolina, Tennessee and Washington State all brought in bans on tipping. However they would all be repealed the following decade. The campaigners would surely be distressed to see the $40 billion spent just over a century later.

Among economists there seems to be a division of opinions. . In a competitive labour market increased income through tipping will in the long run be offset by lower base wages Many see it as wasteful activity. However, not all economists look at it that way.

One group, from the free-market Austrian school, argue that tipping is a market-based solution to a problem of imperfect knowledge. A estaurateur would find it extremely laborious to monitor his entire staff so that he would be able to tailor the wages of waiters and waitresses to their courtesy with customers. One solution is to allow the customers themselves to evaluate their servers’ performance. This not only saves the employer time and money, but allows for the satisfaction of what will surely be heterogeneous preferences among customers. They also posit that as customers (especially male ones) reward physically attractive staff with higher tips, tipping can be understood as a discreet way of channelling the most “appropriate” personnel into this line of work.

This kind of rule mentioned above about male clients rewarding physically attractive staff with higher tips is I suppose not surprising. Here are a few more empirical observations:

Men’s appearance, is not so important.

Waiters get better tips from women than men.

Waitresses get better tips from men than women.

Blondes get better tips than brunettes.

Slender women get better tips than heavier women.

Large breasted women get better tips than smaller breasted women.

Women in their 30s get better tips than either younger or older women.

All these findings come from the work of Michael Lynn who has written more than 50 papers on tipping behaviour. A former bartender, busboy, and waiter, Lynn is currently the Burton M. Sack Professor in Food & Beverage Management at the Cornell University’s School of Hotel Administration. His oeuvre includes:

Reach out and touch your customer.

Gratitude and gratuity: A meta-analysis of research on the service-tipping relationship.

National personality and tipping customs.

Sweetening the till: The use of candy to increase restaurant tipping.

Are Christian/religious people poor tippers?

Clothing colour and tipping: An attempted replication and extension.

Lynn has carried out extensive of research looking at the size of tip and how it relates to the customer’s perceptions of service quality. There is a consistent relationship; people do tip more the better the service they get. But this correlation is rather weak, a mere 0.2. This apparently means about 4% of the variability of the differences in the percentage tips left by different dining parties can be explained by their service ratings.

The professor has also found that the prevalence of tipping decreases as the percentage of national GDP collected in taxes increases. In high-tax Sweden you generally don’t have to leave anything. If you want, you can leave a small tip of 5-10%, or round up the amount of the bill. The idea is that everyone should have a decent wage and so tipping is an extra, not an essential component of the server’s salary.

The likelihood that tipping will vanish is remote. We value people’s esteem and we want to look good and receive a nice smile as we leave the restaurant. I’ll leave you with this classic scene from Reservoir Dogs about tipping:

How to get bigger tips

May 10, 2015

Michael Lynn has published a series of MegaTips, 20 techniques waiters and waitresses can use to increase their tips: 

  1. Use makeup (for waitresses)
  2. Wear something unusual
  3. Introduce yourself by name
  4. Squat down next to the table
  5. Stand physically close to the customer
  6. Touch the customer
  7. Smile
  8. Compliment the customers’ food choices
  9. Repeat the order back to the customer
  10. Build the check with suggestive selling
  11. Entertain the customer
  12. Forecast good weather
  13. Write “Thank You” on the check
  14. Write a patriotic message on the check
  15. Draw a picture on the check
  16. Call the customer by name
  17. Use tip trays with credit card insignia
  18. Give the customer candy
  19. Provide tipping guidelines
  20. Play songs with pro-social lyrics

The Michelin Guide

October 13, 2013

The Michelin Guide is a veritable French institution. Each March, when it is published, it sparks a media frenzy similar to the Oscars. In the days leading up to the announcement speculation is rife, and TV and newspapers discuss which restaurants might lose, and which might gain a Michelin star. The acquisition or loss of a star can have dramatic effects on the success of a restaurant. Chefs spend their careers trying to get and then maintain them. Paul Bocuse, one of the pioneers of nouvelle cuisine in the 1960s, said, “Michelin is the only guide that counts.” The term Michelin Guide refers to the Michelin Red Guide, the oldest and best-known European hotel and restaurant reference guide. The Michelin guide is published in 14 editions covering 23 countries and sold in nearly 90 countries. There are hundreds of thousands of restaurants all over the world, but just 106 of them earned three stars in 2012.

When the tyre manufacturers André Michelin and his brother Édouard first produced it in 1900 there were fewer than 3,000 cars in France, and what they wanted to do was to boost the demand for cars, and get people driving more and thus wearing out their tyres. Originally it was not just about food. It contained useful information for motorists, including maps, instructions for repairing and changing tyres, and lists of car mechanics, hotels and petrol stations. The brothers had nearly 35,000 copies printed and it was given away free of charge. During WWI publication of the guide was suspended. After the armistice, revised editions of the guide continued to be given away until 1920. But when André Michelin noticed copies of the guide being used to prop up a workbench, he decided that enough was enough. We only respect what we pay for so they began to charge. It was at this time that the restaurant side of the guide came to the fore. The brothers recruited a team of inspectors to visit and review restaurants, always travelling incognito. In 1926 the guide first awarded stars for fine dining. Initially there was a single star for restaurants; in 1931 the hierarchy of one, two and three stars was introduced. In 1936 the criteria for the star system was published:

one star: “A very good restaurant in its category” (“Une très bonne table dans sa catégorie”)

two stars: “Excellent cooking, worth a detour” (“Table excellente, mérite un détour”)

three stars: “Exceptional cuisine, worth a special journey” (“Une des meilleures tables, vaut le voyage”).

During WWII publication was again suspended. However the 1939 guide was specially reprinted for the Allied Forces which invaded France in 1944; it was thought to have the best and most up-to-date maps available. And once the war finished, just one week after V E Day, it came out again. Due to the shortages that persisted after the war, Michelin decided to impose an upper limit of two stars.

At the heart of the process are the visits. Restaurants can solicit an inspection. There are also from the readers of the guide. But some establishments will resort to orchestrating campaigns to promote themselves. Derek Bulmer, a former editor of the British edition, cites a restaurant which got people to sign postcards that already had ecstatic reviews written on them. Needless to say it didn’t get a star. Bulmer explains what the inspectors are looking for:

You can’t get a star without quality products that are fresh, seasonal and local. These must be prepared with a high degree of technical skill as part of a well-balanced menu. “The starters have to be as good as the mains, the fish dishes cooked as well as the meat dishes and so on.”

Most places will be seen within 12 months of their request, but they aren’t told when it will be or who will be coming. They typically make between three and six visits, and you have to excel every time. They sample venues at different times of the day using different reviewers each time. They have been known to go as many as ten times. The restaurants will not be told they have been awarded a star until the guide comes out in March. However, when a restaurant gets two or three stars, or if they are going to lose a star, they will be informed beforehand.

These Michelin inspectors always go incognito and their meals and expenses are paid for by the guide, never by a restaurant being reviewed. Michelin takes great pains to maintain the anonymity of its inspectors. According to an article in The New Yorker, many of the company’s top executives have never met an inspector. The Guide recommends that they keep their line of work secret, even from their parents, who might be tempted to boast about it. Obviously the inspectors cannot talk to the press. One man who ignored this prohibition was Pascal Rémy, a veteran Michelin inspector based in France. His exposé of the world of restaurant inspection, L’Inspecteur se Met à Table led to his dismissal in 2004. He brought a court case for unfair dismissal, which was unsuccessful. We may have an image of a glamorous life of a Michelin inspector, but Remy paints a picture of solitude, tedium and drudgery as they drive all over France dining alone every night. He felt that he was underpaid considering the strict deadlines for getting in his reports he had to meet. He also attacked the guide for becoming lax in its standards. In particular he stated there were simply not enough inspectors to do the job adequately. Rémy also accused the guide of being biased. They would give an easier time to such famous and influential chefs as Paul Bocuse and Alain Ducasse, who he described as “untouchable.”

Remy’s criticisms are not the only ones you hear about. There is also said to be a systematic bias French cuisine and dining standards. The case of Michelin and Japan is particularly interesting. In 2009 Tokyo overtook Paris at the city with most three-star establishments, and in 2012 Japan was also the leading three-star nation. The rise of Japan sparked criticism that there were commercial reasons behind the stars; Michelin wanted to gain brand awareness with Japanese customers so that they could market themselves in Japan. Curiously some chefs were not wild about receiving a star, feeling that their restaurants would become too popular and they would end up lowering their quality.

Despite the criticisms there is no doubt that the Michelin Guide retains a lot of prestige. It is a fascinating world, but it is also somewhat alien to me. I have never knowingly eaten in an eatery with Michelin stars. I don’t think my local kebab place will be applying anytime soon.

A couple of videos about foodies

November 24, 2012

This is from The Onion:

And this one is from the comedy Portlandia

Fed up with the Gastroculture

November 24, 2012

Steven Poole thinks we are eating ourselves stupid. Poole is the author of a new polemic called You Aren’t What You Eat: Fed up with the Gastroculture. I have been unable to get hold of the book, but I have heard a number of interviews with the author. While I don’t agree entirely with Poole’s thesis, I do think he is onto something. We are living in an age in which what we eat has become an important way of expressing our identity. Television schedules are awash with cookery programmes. Bookshops are full of the offerings of the nation’s TV chefs. If Gordon Ramsay, Jamie Oliver and Nigella Lawson are too vulgar for you, the patent troll entrepreneur Nathan Myhrvold the patent troll entrepreneur, who I featured a few weeks ago, has published “the cookbook to end all cookbooks“, Modernist Cuisine: The Art and Science of Cooking, a six-volume, 2,400-page set that reveals science-inspired techniques for preparing food. It will set you back £375.25. And Jamie Oliver has been complaining that 30,000 linen napkins a month are stolen from his restaurants ­— it’s almost as though they’re religious relics.  At the heart of this trend is the rise of the foodie.

I have heard different versions of the origin of the word foodie. The OED’s very first citation is from 1980, from a New York magazine piece about a Parisian restaurant. Another variant is that it was first used in a Harper’s & Queen article entitled “Cuisine Poseur” in 1982. Whatever its origins may be, Foodie now seems to have supplanted gourmet everywhere. The latter tem has snobbish connotations. But foodies also claim to have superior powers of discrimination. Poole actually prefers the more pejorative term foodist, which invokes the idea of fanaticism.

Poole takes aim at locavores and organic farming. I have already covered many of the points Poole makes in previous posts. I have no problem with it but for me there is no intrinsic virtue in buying local. If a product can be made cheaper and/or better somewhere else, I think we all benefit from the deal. The concept of food miles is applied very simplistically Transport represents is only one component, less than 10%, of the total environmental impact of food production and consumption. I am also sceptical about organic. I think organic foods are a con. What’s more they are most definitely not the solution for feeding seven billion people.

We also have the rise of celebrity chefs, especially in the USA and the UK. They are in many ways today’s rock stars. Jamie Oliver makes a fascinating case study. He seems to inspire love and hate in equal measure. I am more inclined to the former. He does have an evangelical passion for food. But there are times when it can be cringe-inducing. I thought that his campaign to reform school dinners was a noble one; I was shocked at what kids were being given to eat. If I were to criticise any aspect, it would be that he tried to change too much with the subsequent backlash from some parents. Matters came to a head in Rotherham, where parents started taking lunchtime fast food orders to pupils at RawmarshCommunitySchool. Who can forget the pictures of parents pushing fast food orders through school railings? Maybe ratatouille pancakes were just a bit too exotic. Oliver has been described as a serial glutton for punishment; he actually went back to the Yorkshire city to make his Ministry of Food. He was not given a warm welcome by everyone. When he spoke to 5,000 fans at Rotherham United football club they drowned him out with chants of “Who ate all the pies?” His attempts to convert Americans to healthy met with similar hostility.

What really irks Poole is food snobbery. There is a notion that if you don’t care about food as they do, there is something wrong with you. I think there are so many other fascinating things in the world. There is an air of moral superiority. The masses are eating badly and we, the experts, must somehow educate them or force them into what we think they should eat and they should be prevented from eating what is bad for them. This kind of snobbery is faithful reflection of the human character. We enjoy engaging in this kind of one-upmanship: I am more organic than year. I buy all my goods from farmers’ markets. I have tried more exotic foods than you. I am a more ethical eater than you. While sex has gone in the other direction, food is now marked by a whole series of taboos. We are much less tolerant of people’s food choices than we used to be.

I do disagree with Poole in some aspects. I think that we know more about food than ever before. We have become very cosmopolitan in our tastes. The variety of food you can see is breathtaking. There has never been a better period to experience quality and innovative food dishes. However, at the same time there is a lot of rubbish out there. And then we have the problems of obesity and hunger co-existing in the world.

In this debate about foodies I also see a parallel with linguistic snobbery. I love language, and I hope I have been able to reflect this sentiment in this blog. Language should be celebrated for its beauty and diversity. But I do not see it as weapon with which to demonstrate some kind of social superiority. I feel the same about food. Perhaps Poole has the wrong term – we should be really talking about food pedants. I think it s great when people are passionate about something. However, there can be thin line between passion and pedantry.

I think therefore I am drunk

June 16, 2012

We will never know the name of the first human who thought that it would be wheeze to consume the juice of fermented fruit. Nor we do know when it would have been. Definite evidence of the preparation of alcoholic drinks dies not surface until around 8000 BC after humans discovered the joys of agriculture.  In Uruk, the principal city of Sumer brewing was practiced on a massive scale. Drinking wherever it takes place is fundamentally a social activity. We tend to drink in socially, integrative, egalitarian environments which serve to foster social bonding. There is a universal nexus with celebration; alcohol is an essential element of festivity.

Since it first appeared alcohol has been credited with magical powers. Now in Britain alcohol is said to make us violent, anti-social obnoxious, promiscuous, and much more. The press rails against the culture of binge drinking. What substance is capable of doing this to us?  The substance at which is the chemical soul of all alcoholic drinks is ethanol, a colourless and highly volatile liquid. It is classified as a depressant and it effects on the drinker vary in accordance with the quantity consumed. In sufficient doses, alcohol impairs our coordination, reaction times, muscle control, short-term memory, ability to speak clearly and general cognitive abilities. In very high doses it can be fatal.

How does alcohol affect behaviour? There is enormous cross-cultural variation in the way people behave when they drink. Anthropologists argue that the effects of alcohol on behaviour are determined by cultural rules and norms, not by the chemical actions of ethanol. In this view the cross-cultural study of alcohol is like a massive natural experiment on a global scale. The reaction of Homo Sapiens to this substance, ethanol has produced results that vary enormously across our planet. In some societies, the UK being one, alcohol is associated with violent and anti-social behaviour, while in others, such as the Mediterranean, drinking appears to take place in an atmosphere of relative   peace and harmony. The Yuruna Indians in South America consume copious amounts of moonshine without losing their inhibitions. In an anthropological survey of 46 societies, a link between alcohol and violence was only found in one fifth. In their landmark 1969 book Drunken Comportment the anthropologists MacAndrew and Edgerton drew this conclusion:

Over the course of socialization, people learn about drunkenness what their society “knows” about drunkenness; and, accepting and acting upon the understandings thus imparted to them, they become the living confirmation of their society’s teachings.”

It is not just scientists who are challenging assumptions about how alcohol affects us. Psychologists refer to the think-drink effect, the observation that behaviour is more closely related to perceived alcohol consumption than it is to actual consumption. In a series of ingenious studies in the 1970s and ’80s, psychologists at the University of Washington in Seattle led by Alan Marlatt put more than 300 students into a simulated bar-room with mirrors, music and the classic pine bar. The psychologists organised a double blind study.

25% were given a vodka-tonic and were told that it contained alcohol. 

25% were given a placebo but told that it contained alcohol

25% were given a non alcoholic drink and were told that it didn’t contain alcohol.

25% were given alcohol but were told that their drink contained no alcohol

The drinks had to look and taste the same.  The vodka and tonic was mixed in the ratio 1 to 5, to prevent the participants from recognising the alcohol by the taste. And to make doubly sure, they received a dose of mouth-spray before drinking. There was an electronic alcometer, but it had been rigged to show the students what they believed they had been drinking The students typically downed five drinks in a period of one or two hours.

The studies found that people who thought they were drinking alcohol behaved exactly as they expected to when drunk. Marlatt could find no significant difference between those who consumed alcohol and those who didn’t. Men who believed that they had been drinking alcohol became less anxious in social situations even when they had been drinking placebos. Women, by contrast, became more anxious. Men became more aggressive when they were drinking only tonic but thought that it contained vodka. When the situation was reversed they become relatively less aggressive even though they were actually imbibing vodka. Men also became more sexually aroused when they believed they have been drinking. Women also reported an increase in libido, but curiously, a measure of their vaginal blood flow showed that they were actually becoming less physically aroused.

The social anthropologist Kate Fox has argued that we could substitute coffee for alcohol and produce similar results:

If I were given total power, I could very easily engineer a nation in which coffee would become a huge social problem – a nation in which young people would binge-drink coffee every Friday and Saturday night and then rampage around town centres being anti-social, getting into fights and having unprotected sex in random one-night stands.I would restrict access to coffee, thus immediately giving it highly desirable forbidden-fruit status. Then I would issue lots of dire warnings about the dangerously disinhibiting effects of coffee. I would make sure everyone knew that even a mere three cups (six “units”) of coffee “can lead to anti-social, aggressive and violent behaviour”, and sexual promiscuity, thus instantly giving young people a powerful motive to binge-drink double espressos, and a perfect excuse to behave very badly after doing so.I could legitimately base many of my scary coffee-awareness warnings on the known effects of caffeine, and I could easily make these sound like a recipe for disaster, or at least for disinhibition and public disorder. It would not take long for my dire warnings to create the beliefs and expectations that would make them self-fulfilling prophecies. This may sound like a science fiction story, but it is precisely what our misguided alcohol-education programmes have done.

I think Fox does overstate the case. Nonetheless I am intrigued by the interaction between the very real physiological effects of alcohol and the suggestibility of the human mind. However, if you are stopped by the police on suspicion of drunk driving, I really don’t think it would be a good idea to cite studies suggesting that drunkenness is socially constructed.