Is America a nation of gullible nitwits? For the record, there is no country on earth that can cast the first stone. Still, judging by the blind faith in loopy science that has turned the gluten-free diet into a $23bn movement, it is a valid question.

Gluten is a “gluey” protein found in wheat, barley and rye. It makes cakes go fluffy and bread taste moist. Wheat was one of the first domesticated food crops and is a staple food around the world. Nevertheless, a third of Americans now avoid gluten in the belief that it causes a range of ills from diabetes, obesity, autism and Alzheimer’s to joint pain, flatulence and diarrhoea.

A minuscule market that once served the 1% of Americans who have coeliac disease (and must avoid gluten) now commands the top shelves in the food aisles. Of all the egregious examples of corporate welfare, our paying huge premiums to Kraft and Kellogg’s for non-existent health benefits must take the gluten-free biscuit.

The only comfort in all this gluten madness is that it will pass. In time this particular fad will go the way of all the other food diets that have gripped the country since the 1900s, when Horace Fletcher convinced Americans to chew each mouthful 32 times. From low-carb to fat-free, from the Beverly Hills diet (fruit, then food combining) to the blood-type diet, they have each come, conquered and left with a huge payoff.

It isn’t surprising that food crazes have such a grip on collective behaviour in America. Perfectionism and group assimilation have been a part of the country’s core identity since the arrival of the first settlers. In 1630, while sailing to America, John Winthrop, who went on to become the first governor of the Massachusetts Bay Colony, preached a sermon about life in the New World. It would require the settlers accompanying him to dedicate themselves to a life of perpetual striving: “We shall be as a city upon a hill. The eyes of all people are upon us.”

Surveys conducted by the International Social Survey Programme (ISSP) show that Winthrop’s words struck deep. Americans are among the most likely to agree with the statements: “People should support their country even if the country is in the wrong” and “People should obey the law without exception”.

Does this mean that a certain lemming-like behaviour is conditional for acceptance into the American polity? That belonging requires a subtle lobotomy of the senses? In the 19th century travellers to the United States rather thought so. They continually remarked on the heavy hand of conformity that characterised American society.

In the early 1830s the actress Fanny Kemble complained that no one ever deviated from accepted norms; even unconventional behaviour had its own strict conventions. The people, she remarked, were just “moral and mental lithographs . . . The fact is, that being politically the most free people of earth, the Americans are socially the least so.”

Charles Dickens agreed. “Freedom of opinion! Where is it?” he wrote during one of his lecture tours. “If [I had] written my books in this country . . . I should have lived and died, poor, unnoticed, and a ‘black sheep’ — to boot.”

Alexis de Tocqueville made a similar observation in his book Democracy in America. He admired the country but feared that it had broken one set of shackles merely to wear another — the tyranny of the many: “In the United States the majority undertakes to supply a multitude of
ready-made opinions for the use of individuals.”

It is safe to say that Americans did not share the world’s view of them as unreconstructed conformists. The titles of two of the most influential works of the 19th century, Self-Reliance by Ralph Waldo Emerson (1841) and On the Duty of Civil Disobedience by Henry David Thoreau (1849), rather give the game away.

Both authors argued that Americans had a duty to be sceptical of the state; moral authority could come only from within. “That government is best which governs not at all,” argued Thoreau.

This complacency evaporated, however, after the First World War. Journalists who worked for President Woodrow Wilson to convince pro-German, isolationist Americans to become pro-British interventionists were appalled at how easy it was to manipulate public opinion.

One journalist, a nephew of Sigmund Freud named Edward Bernays, later used the skills he learnt to become the father of public relations. During the 1920s he single-handedly broke the social taboo against women smoking by turning the habit into a feminist issue. Somehow he convinced the campaigners for women’s rights to demonstrate their independence by lighting up “torches of freedom” during protest marches.

By the 1950s writers and philosophers had turned American conformity into an existential crisis. Once again the titles say it all: The Man in the Gray Flannel Suit, The Lonely Crowd and The Organization Man. Just like Holden Caulfield in The Catcher in the Rye, suddenly everyone hated the phoneys, which meant they hated themselves. Hello the Sixties.

Yet here we are today with conformity no longer considered a philosophical issue but a genetic one. Researchers have discovered that monkeys are just as obsessively conformist as any meeting of a Republican women’s club. Our brains are apparently hard-wired to enjoy following group behaviour.

All this proves that living in a free society is not without its challenges. Equality is not synonymous with individuality. Democracy may be the highest form of self-expression but it also calls for the greatest self-control.

A body politic founded on voluntary communalism places psychological demands on its members even without the extra nudge from neural pathways. For many Americans it means believing in gluten-free foods, “toe” shoes, body piercing, country music, using the word “like” in every sentence, shopping centres and daytime TV.

Gullible and idiotic, without a doubt; it is also the price America pays for liberty.