The (slow) dying of cultural forms
Several years ago, sipping coffee at the sunny campus of Stanford, J.D. Porter, from the Literary Lab, and I were discussing cultural evolution. I tried to persuade J.D. that thinking of cultural items as “species”, which evolve, mutate, and get extinct, is a useful metaphor — or even more than just a metaphor. But J.D. was skeptical. Cultural items, he said — for example, poems — rarely die. Shakespeare wrote Romeo and Juliet around 1591, and yet, this play is still alive and kicking: maybe even more alive than during the times of Shakespeare. So how can we speak of “cultural selection” and “evolution” if cultural “species” — at least some of them — refuse to die?
A similar point was made by Kevin Kelly, the former editor of Wired, in his book What Technology Wants:
“With very few exceptions, technologies don’t die. In this way they differ from biological species, which in the long term inevitably go extinct. Technologies are idea based, and culture is their memory. They can be resurrected if forgotten, and can be recorded (by increasingly better means) so that they won’t be overlooked. Technologies are forever.”
If dying is a necessary part of evolution (and it seems to be), how can we speak about the evolution of something that is “forever”?
During that conversation, I didn’t immediately find a good answer. But the question stuck in my head. The question, which, truth be told, is rarely asked by the proponents of cultural evolution. There are many studies analysing how cultural items become successful, but how they die… I don’t know many of those. This is why I was happy to see a recent paper by Cristian Candia and colleagues titled “The universal decay of cultural memory and attention”.
So, a decay, not death — but these two are fairly similar. The main point of the paper can be illustrated with a plot, which is repeated throughout the paper, in different incarnations, a dozen or so times: it shows that all cultural items — songs, films, academic papers — once appeared, slowly “die out”, slowly become forgotten by the society.
The paper has a more specific point too: that each of these curves is biexponential — it can be described by a combination of two exponential decay functions, as shown on Figure 2.
These two functions (and here comes the most controversial claim in the paper) are two types of collective memory: the short-lived, oral “communicative” memory, and long-term, written “cultural” memory. I am not convinced that this is the best explanation for the shape of cultural decay, but this isn’t even so important. Two other questions interest me more. First, how universal is this “universal” decay? And, second, what does this decay mean for our understanding of “death” in culture?
First, about universality. All the types of data used in this paper (songs, YouTube videos, academic citations, and several more) represent a very specific kind of culture: they may be called disposable culture, culture for a limited number of uses. Take, for example, films or Youtube videos: we rarely watch them more than once. Or academic papers — here, the story is similar: we rarely reread them (except for, maybe, a few classical pieces). Music, too, seems to have a limited lifespan: after multiple listenings, even our favourite songs wear out. For such disposable culture, the biexponential function works fine.
But what about other kinds of culture, which don’t have any limitation on the time of use? Let’s take a banal example: hammers. Invented thousands of years ago, they are probably more widespread than ever. There is no decay, because hammers can be used without ever becoming “boring”. They aren’t disposable, they are reusable — unlike books, films, or academic articles. Can we describe the history of reusable culture with the same decay function? I doubt so.
Now, the second question: is the decay function, even if it isn’t universal, helpful in understanding the death of cultural items? As I’ve already said, cultural items don’t have a natural limit to their lifespan. A person can live around a hundred years, but rarely longer. A painting can “live” for many hundreds of years. Even if a painting gets completely forgotten — when there is no single person on Earth who has seen it — it still isn’t dead, technically, if its copy is kept, covered with dust, somewhere in the museum stacks.
Candia et al.’s paper hints at a solution of this problem — and this is exactly why I was happy to see it. In biology, death is a qualitative change: there is a huge difference between a living and a dead organism. But in culture… death is quantitative. So: cultural death isn’t like crossing a border, it rather resembles a slow process of collapsing. And some cultural forms (or, according to Kelly, most of them) never fully collapse: they simply become infinitely closer to death, without ever reaching that final destination point. Shakespeare, as a cultural character, having reached his peak popularity almost a century ago, is slowly decaying from our cultural memory (Figure 3). Yes, his plays aren’t dead, but they are in the process of dying — for sure.
The slow dying of cultural forms… It may be worth studying further.
