The Roman Philosopher Lucius Anneaus Seneca (4 BCE-65 CE) was perhaps the first to note the universal trend that growth is slow but ruin is rapid. I call this tendency the "Seneca Effect."
Showing posts with label vitamin D. Show all posts
Showing posts with label vitamin D. Show all posts

Sunday, August 1, 2021

The Truth About Décolletages: an Epistemic Analysis

This image represents the rape of Cassandra, the Trojan prophetess. It was 
probably made during the 5th century BCE (Presently at the Museo Archeologico Nazionale, Napoli, 2422). Note the partial nakedness of the figure of Cassandra: the ancient didn't see female breasts in the same way we do nowadays. Instead of being an erotic symbol, they were seen as a sign of distress. Cassandra's rape scene was almost always represented in this way, but it is not the only example. It is not easy for us to understand why our perception of this anatomic feature of human females has changed so much, but is not impossible to propose reasonable hypotheses. In this post, you'll read about one of these hypotheses from the book "The Empty Sea" (Springer 2020) by Ugo Bardi and Ilaria Perissi. But I'll start with some epistemological considerations.

Science is supposed to tell us what things really are. But is it true? In recent times, the prestige of science seems to be declining for various good reasons. An example: in his "Red Earth, White Lies," Vine Deloria, Jr. starts with a citation from the 1973 series by Jacob Bronowski, "The Ascent of Man.

"Why are the Lapps white? Man began with a dark skin; the sunlight makes vitamin D . . . in the North, man needs to let in all the sunlight there is to make enough vitamin D and natural selection therefore favoured those with whiter skins."

Deloria notes that "Lapps may have whiter skins than Africans, but they do not run around naked to absorb the sunlight's vitamin D." From this, he says that "my faith in science decreased geometrically over the years."

As a first reaction, Deloria's position is understandable. How could it be that a renowned author such as Jacob Bronowski (1908 –1974) uttered such a silly statement? But, as always, things are more nuanced than they seem to be. It is true that Bronowski was somewhat careless, but it is also true that Deloria played a typical game of rhetoric by using a single sentence out of context.

Read the whole paragraph and you'll see that Bronowski did NOT say that the Lapps are white because they live in the North. He was just comparing the time scales of cultural and genetic adaptations, noting that the Sami (once called "Lapps") maintained a skin color that they had inherited long before from their remote ancestors. When they migrated to their current lands, the Sami didn't need to expose their skin to the Sun simply because their traditional diet included plenty of fish and that provided them with abundant vitamin D. (of course, nowadays they may well subsist on fast food, but it is another story) 

But Deloria's position should not be banalized, either. True, his chapter on "Evolutionary Prejudice" is mainly a series of statements of disbelief. But, if he takes this position, there has to be a reason and the reason is that science often does not hold up to the lofty promises made to everyone. Not rarely, we are presented with a kind of science that cannot be discussed, doubted, or criticized just because it is "Science" with a capital letter. 

The problem is that science has been badly banalized, bowdlerized, politicized, financialized, and more. With scientists nowadays selling themselves cheap to whoever wants to buy them, it is hard to discount Deloria's position. Like him, I am starting to distrust scientists. 

But I still believe in "science." Science is, in the end, a set of epistemic tools. It is up to us to use them well, not as an excuse to disparage the wisdom of our ancestors. Science has little to do with the TV utterances of pompous scientists. It is not represented by the inflated claims of the newest trick that, maybe, will solve this or that problem. It is not about the silly power games that academics play, those who pretend to teach our young how to behave. It does not tell us to do things we feel are wrong to do and, if it does, then it is wrong science. 

True science, as the name says, is about knowledge, and knowledge is never fixed, never complete, never written in stone. Like the universe, knowledge changes all the time, and change is what we need to learn to appreciate. Science doesn't give us absolute truths. But it does tell us something about the infinite variety of the way the universe works and its beauty -- ultimately a homage to the Goddess of Earth, Gaia. This is the kind of science we can trust. 

About the specific issue that Deloria and Bronowski raised, the color of the human skin, I do think that there is a lot of merit in the scientific explanation that attributes it to the fact that humans need to be exposed to the sun to synthesize vitamin D inside their bodies. It is a fascinating story that deserves to be learned as part of the human adventure that started tens of thousands of years ago, and that is still ongoing. 

On this matter, I and my colleague Ilaria Perissi even played with the hypothesis that the need for vitamin D was the ultimate reason for the fashion of woman décolletage that started in Europe with the waning of the Middle Ages. 

We discussed this matter in our recent book "The Empty Sea." It is a book that deals mainly with the economics of marine resources and, in exploring this subject, we found plenty of unexpected facets of how differently humans behave (you may also be interested in a short theater performance by the authors!). I am presenting to you an excerpt from the book that I hope you'll enjoy. Don't take it as the absolute truth: it is just a possible facet of it. And we continue learning!


From "The Empty Sea," by Ugo Bardi and Ilaria Perissi, Springer 2020.

Here, we are going to propose to you the hypothesis that the fashion of women’s décolletage is related to fishing. No, it is not because human females copied the fashion of going around topless from mermaids! It is a more complicated story of interrelationships in human culture and society, one of those relationships that often lead to unexpected consequences. But let us start from the beginning.


Figure 14 – Roman statuary piece, probably representing Thusnelda, the wife of the German leader Arminius. It is presently at the Loggia de’ Lanzi in Florence, Italy.

As we all know, female breasts are something very popular with human males, nowadays. But that may not be the same in all cultures and, in particular, it was not the same in the past. It would be a long story to tell, but let us just note that, in classical times, when you saw the breasts of a woman exposed in a piece of statuary or in a painting, it did not signal sexual attraction but distress. You can see that well in the picture of a Roman statuary piece, presently in Florence, that may go back to the 1st century CE. It is said to represent Thusnelda, the wife of the German leader Arminius who had defeated the Romans at Teutoburg in 9 CE. Later on, the Romans managed to capture Thusnelda and they were obviously happy that they could show her sad and distressed as a war prisoner.

We find little trace of erotic interest in female breasts in European art until the late Middle Ages, when the fashion for women of flaunting their cleavage at men started. It was the origin of the fascination with breasts -- we could say “fixation” -- typical of our times. But, if something exists, there must be a reason for it to exist. What caused this cultural change to appear and spread?

To find the explanation, we can go back to the times of the fall of the Roman Empire, around the 5th century AD. When the empire collapsed, the center of gravity of the population of the Western tip of Eurasia shifted northward. It was a slow process that saw northern Europe change from a land of sparse and nomadic populations to a highly populated and urbanized area. Of course, this large population had to be fed and, in earlier times, fish represented a fundamental element of the diet of northern Europeans. But fishing could not keep pace with the growing population. Not only the amount that could be produced was limited, but there were no refrigeration technologies that could have allowed the distribution of fresh fish inland. So, from the Late Middle Ages, northern Europeans relied mostly on agricultural products for their diet: grain, barley, wheat, and the like.

At this point, there arose a problem with the new diet: it was poor in vitamin D. Humans badly need this vitamin, lacking it leads to rickets: weak bones, and other related illnesses. But the human metabolism is unable to synthesize vitamin D by itself, so humans can obtain it in two ways: from food that contains it, typically fish, or from a chemical reaction that takes place in the human skin when exposed to ultraviolet radiation from the sun.

Now you see the problem with getting enough vitamin D in northern Europe: not enough sun. It was probably the same problem that led our remote Cro-Magnon ancestors, originally dark-skinned, to acquire a pale skin when they migrated to Europe from Africa, some 40,000 years ago. Pale skin is more easily penetrated by ultraviolet radiation and that helps to make more vitamin D. But, during the Middle Ages, northern Europeans could not get paler than they already were, and if they ate a diet poor in fish, it is certain that they didn’t have enough vitamin D. Data are lacking for ancient times, but rickets has been an endemic disease in northern Europe up to relatively recent times.

A way to get more vitamin D is to expose a larger fraction of one’s skin to the sun. Indeed, you may have noticed how modern Northern Europeans apply this tactic in summer when they tend to stay in the sun as much as they can, while rather scantily clad. But, during the Middle Ages, dress codes were tighter than they are nowadays. For men, then as now, there was no problem with wearing shorts or going shirtless. But for women it was more difficult: baring one’s legs was considered sinful beyond the pale, to say nothing about going topless. What women could do, though, was to bare a part of their skin that was not considered too sinful for males to behold: their necks and shoulders.

Note that during the Middle Ages nobody had the scantest idea of what vitamin D could be and of its relationship with sunlight and human skin. Just like our Cro-Magnon ancestors had not planned to get pale skins, the diffusion of décolletages was probably a question of trial and error. With the vagaries of fashion, women who exposed more of their skin to the sun had a better supply of vitamin D. They were healthier and they were imitated.

It was the start of the fashion of the low neckline that was gradually lowered more and more until it arrived to show part of a woman’s cleavage. We see this fashion expanding in European art from that period. In the figure, you see an example in a miniature made by the Italian painter Giovanni di Benedetto da Como in 1380. Note how splendidly dressed these ladies are, they are true fashion models. And note their ample décolletages. It was a brand-new fashion for those times that is lasting to this day, the origin of our modern fascination with a specific part of the human female anatomy.                                                                        

Of course, we are presenting to you just a hypothesis: we have no quantitative data on the incidence of rickets in the late Middle Ages, nor statistical data on the benefits of décolletage at that time. But, from what we know about vitamin D and human health, décolletages must have helped the people of Northern Europe of that time and so we believe that the fisherman’s curse is a possible explanation for the diffusion of décolletage in Europe. We leave it to our readers to decide how likely it is that this is a correct explanation.