The Secret History of Tamales Offers a Lesson in Humility

I really like tamales, the cakes made from ground corn, stuffed with a savory or sweet filling, and steamed in corn husks or banana leaves. For one thing, they taste good. But tamales are also a powerful historical lesson about humility: most of the time, we don’t understand why rules are good, and we certainly should doubt our ability to choose reforms that will be better.

The corn flour from which tamales are made is masa harina, a nixtamalized hominy that is dried and ground up. Corn is an entirely GMO product, the result of thousands of years of Mesoamerican selective breeding. The result is a remarkably hardy and nutritious product that has — after it was “discovered” by Europeans — taken over much of the world; corn (or maize) is by far the largest crop of any grain, with corn output nearly matching wheat and rice output combined.

But Europeans screwed it up, because they were so arrogant about their “science” that they ignored the knowledge dispersed in the traditions of those who had actually invented corn. The Mesoamericans, for the most part Nahuatl (a language and ethnic group that includes the Aztecs), didn’t just eat the corn unprocessed, or at least not all of it. They nixtamalized it. This concept derives from the Nahuatl word for hominy, whose name in turn comes from nextli (“ashes, lime”) plus tamalli (“something wrapped”).

Why did the Nahuatl soak the corn in lime (water mixed with wood ashes, which creates a strong basic solution with lots of potassium hydroxide)? Potassium hydroxide is an extremely powerful and potentially dangerous chemical, but the effect on corn is to soften the husk so it can be removed and to cause the kernels inside to swell into the hominy we think of as being almost a different product.


It also does something else, something that the Mesoamericans could not explain and that the Europeans did not understand. Nixtamalization liberates vitamin B3, or niacin, in large quantities in the resulting flour. If you grind dried corn, no niacin. If you nixtamalize corn, rinse the “lime” solution away, let the resulting swollen kernels dry, and then grind them, lots of niacin. Nixtamalization also made other nutrients, including protein, more readily digestible, increasing the effective metabolic yield of eating corn.

It’s easy to understand why the arrogant, supercilious Europeans decided to skip all those silly, superstitious steps of taking ash from old fires and mixing it into the corn, and then drying the result. It’s inefficient, and clearly just some old superstition, right? The Aztecs, when asked, would say that nixtamalization had been revealed to them by the god of corn, Centeotl, as a secret that benefitted them at the expense of their enemies.

Corn seemed like the perfect food for poor people because it grew fast, had huge yields, and provided carbohydrates, protein, and fat all in one package. Plus, it was versatile and could be consumed off the cob, cooked, or dried and ground into flour.

But by the middle of the 17th century, there was a large outbreak of what they called “Asturian leprosy”; in Italy the disease had become very widespread, and was called pelle agra (pelle = skin; agra = sour), which is where we get the modern name for niacin deficiency: pellagra. (For a history of the problem, and current situation, see this.) Symptoms included light sensitivity, aggressive behavior, lesions, weakness, confusion, and sometimes even dementia or paralysis. Many people died.

Unintended Results

The problem was intractable: in South Carolina, 1,306 people died during the first 10 months of 1915; 100,000 Southerners were affected with pellagra in 1916. Unsurprisingly, scientists were stumped, believing that some pathogen or unknown toxin in local corn caused pellagra. That is, people thought pellagra was caused by eating corn, because the people who developed pellagra were poor and ate mostly corn mush and cooked corn, with just a few other food items.

But corn wasn’t the problem. The problem was ignoring the concentrated and useful information that had been available all the time. Pellagra was essentially unknown in Mesoamerica, even though the diets of many people were based almost entirely on corn and products made from it. The difference was the “superstition” that those savages were clinging to. They didn’t perform the cumbersome nixtamalization process because they knew about niacin, of course; they did it because their religion demanded it.

But the success of tradition is not random, and it is not devoid of information, if you know where to look. It is not hard to imagine the process by which nixtamalization became the dominant process, after all. When corn was first genetically engineered, over the course of centuries of selective breeding, there were likely a variety of practices for preparing and cooking the resulting kernels. Some people may have mixed the dried corn with wood ash, others with chopped cactus or agave, and still others prayed and made incantations. Actually, they probably all prayed and made incantations, and developed a pantheon of gods and a complex set of rituals revolving around the planting, harvesting, and consuming of the sacred maize.


Over the decades, in a relatively short span of years by evolutionary standards, it turned out that some practices were favored by the gods. After all, those who engaged in nixtamalization were healthy and strong, and their children were far more likely to survive into adulthood. Those who used any other practice were sick, unlikely to have healthy children, and very likely to die of malnutrition or be killed in combat. It is likely that the evolutionary process homed in on a precise set of optimal practices, in fact, because the societies that were competing were relatively isolated from the outside world but always struggling against each other for supremacy.

Further, humans can mimic and adapt simply by changing behavior. Biological evolution takes time — a giraffe can’t make its neck longer just by thinking about it — but institutional evolution can take place through conversion. When outsiders converted to the worship of the suite of Nahuatl gods, Centeotl and nixtamalization came along with the package. It may be true that no one understood why the rules were good, but it was enough that the rules were good and that the society flourished.

My little example has been intended as a small piece of evidence in support of a much larger point. As F.A. Hayek put it in The Fatal Conceit,

To understand our civilisation, one must appreciate that the extended order resulted not from human design or intention but spontaneously: it arose from unintentionally conforming to certain traditional and largely moral practices, many of which men tend to dislike, whose significance they usually fail to understand, whose validity they cannot prove, and which have nonetheless fairly rapidly spread by means of an evolutionary selection — the comparative increase of population and wealth — of those groups that happened to follow them. The unwitting, reluctant, even painful adoption of these practices kept these groups together, increased their access to valuable information of all sorts, and enabled them to be 'fruitful, and multiply, and replenish the earth, and subdue it' (Genesis 1:28). This process is perhaps the least appreciated facet of human evolution.

Does this mean science should be scorned? Of course not. Today, pellagra is once again very rare, at least in developed nations. Vitamin supplements and other sources of niacin are very effective in preventing the disease.

What’s interesting about this “cure” is that it took science more than three full centuries, from 1650 to 1960, to reach the stage of knowledge that had been achieved by Mesoamerican traditions a thousand years earlier.

We may not grasp how essential systems work, but that means that we should always be skeptical of proposals to change those systems based on the “science” that reformers imagine they understand.

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Michael Munger

Michael Munger is Professor of Economics at Duke University and Senior Fellow of the American Institute for Economic Research. His degrees are from Davidson College, Washingon University in St. Louis, and Washington University.