The persistence of old inventions

By Gordon Rugg

Old inventions seldom die; usually, they fade into the background, and then hang around there for a surprisingly long time.

In this article, I’ll look at how this happens with physical inventions; how it happens with innovative ideas; at what is going on underneath the regularities; and at what the implications are. A lot of those implications are important, and counter-intuitive.

I’ll start with pointy sticks.

Image credits are at the end of this article.

Pointy sticks were invented long before modern humans arrived on the scene. One of the images above shows the Clacton spear, which is about 400,000 years old. It’s a sophisticated artefact, which required a fair amount of planning, and a fair amount of skill in manufacture. There’s an excellent article by Haidle about the complexity of ancient spear manufacture: Haidle, M.N. (2009) How to think a simple spear, in de Beaune, S.A, Coolidge, F.L, & Wynn T. (eds): Cognitive Archaeology and Human Evolution. Cambridge University Press, Cambridge, UK, pp 57–73.

So what happened after spears were invented? The answer is that they remained in widespread use for a very, very, long time.

Cavalry were still using lances (spears by another name) in European warfare within living memory, for the simple reason that they worked. The urban legend about Polish lancers charging German tanks in World War II is a serious misrepresentation of what was actually a successful charge by Polish cavalry within a battle involving a mixture of cavalry, tanks, anti-tank artillery and infantry.

Infantry still use spears, for similar reasons, but in a different form; now, they take the form of a bayonet on the end of a rifle. In addition, spears are still carried for protection against wildlife in many parts of the world. In fact, if we count bayonets as spears, there are probably more spears in existence today than at any given time in human prehistory up to about ten thousand years ago.

When you start looking closely at inventions, you start seeing the same pattern over and over. A new invention might become much more common than the old invention that it supplants, but it rarely drives the old invention to complete extinction. What happens much more often is that the old invention remains in use in a smaller niche than before.

Often, the old invention remains in use because it retains prestige (e.g. social cachet associated with owning a horse and carriage even today, when cars are have largely supplanted carriages for practical transport).

Often, though, the old invention remains in use for practical reasons, because it is better for particular niches than the new invention. For example, metal has largely supplanted clay as the material of choice for cooking vessels, but clay is still the material of choice for e.g. slow cookers, where the thermal properties of clay are better than those of metal. Another common dynamic is where the old invention is more cost-effective or practical on a small scale, such as the garden spade versus the tractor. The image below on the right shows a reconstructed ancient Roman kitchen; it consists almost entirely of items that are easily recognisable today; shelves, storage vessels, worksurface, cooking vessels, cooking implements, etc.

Image credits are at the end of this article.

There are a few examples of an invention going completely extinct. An example is Roman dodecahedrons, on the left in the image above. Nobody knows what they were used for, but they were widespread in the Roman Empire. They’re very much the exception; most Roman artefacts are immediately recognisable today, even if they might now take a different form, as with the reconstructed Roman kitchen.

Plateau effects

Another common pattern is that an invention begins with a period of experimentation, trying out different designs and materials, and then stabilises in a form that changes very little over very long periods. With weaponry, for example, the basic form of the spear stabilised over three thousand years ago, and remained almost unchanged well into living memory. The same is true of artefacts as diverse as cups and chisels.

It’s a classic S shaped curve, where a (usually) slow initial stage is followed by a (usually) brief period of experimentation and development, and then a (usually) long plateau of little change, once an optimal design has been achieved, in terms of ergonomics and efficiency and cost-effectiveness. Usually, minor changes occur when a new material or process etc changes the game; for example, a new type of alloy, or of manufacturing. Otherwise, though, the core design tends to remain stable.

Innovative ideas

If that’s the case for physical inventions, is it the case for abstract inventions, in the form of ideas that offer explanations, or guidance on how to handle situations?

The short answer is that I don’t know, but I suspect that it is the case. Ideas can have a very long life, in the order of thousands of years. To some extent, the full story is obscured by the existence of writing, which can preserve an idea for as long as the writing can be read and understood.

I’ll start with the concept of revenge. This concept is widespread across cultures, including cultures without writing. It’s at the heart of a cycle of plays more than two thousand years old, the Oresteia.

These three plays examine the dynamics and the consequences of revenge, following the protagonist Orestes as he tries to handle conflicting moral imperatives. They end with Orestes breaking the endless cycle of revenge and counter-revenge by submitting his case for trial by jury. This is portrayed as an innovation that offers new hope to humankind.

Over two thousand years later, trial by jury is still in widespread use, often with the same number of jurors (twelve) as in the Oresteia.

A less edifying example of persistence is jokes involving play on words. In the Odyssey, Odysseus tells the giant Polyphemus that his name is Nobody. Then, after Odysseus and his crew have blinded Polyphemus, Polyphemus tells his fellow giants that Nobody has hurt him, so the giants assume that his blindness came from the gods, not from humans, and so the crew manage to escape. More than two thousand years later, plays on words about people’s names are still a standard feature of popular culture, as in one of the running jokes in The Simpsons.

So what’s going on here, to explain the persistence of ideas across so much time? With the concept of trial by jury, one simple and plausible explanation is that this concept has reached the plateau; it’s an invention that can’t be significantly improved within current constraints, like the ceramic cup or the hammer. We can to some extent measure the efficiency and effectiveness of this concept via approaches such as game theory, which allow us to model the outcomes from strategies such as “Tit for tat” (revenge and counter-revenge).

Persistence in jokes and stories

A similar effect appears to hold for jokes, and for folk tales/urban legends. In all these cases, there is continuity over centuries or millennia.

There’s a temptation is to ascribe this persistence to a vague concept called “human nature”.

However, if we look at the deep structure of these apparently unrelated topics, a very different insight emerges. I’ll focus on jokes, which are easier to explain cleanly, but a very similar dynamic applies to folk tales and urban legends.

There are deep structures in jokes, typically involving a sudden switch from one possible explanation of events into a very different explanation. I’ve blogged about this here. A similar dynamic applies with folk tales and urban legends, where there’s a set-up part of the story, followed by a punchline.

From this point of view, we can assess jokes in terms of their efficiency in handling the switch, and degree of difference between explanations. An example is the 1-2-3 joke structure, where the first two examples establish the pattern underlying the first explanation, and the third example is the punchline that reveals the second explanation. The smallest number that can appear to show a pattern is two, so this structure is about as efficient as it can be.

Plays on words are based on a similar deep structure, but instead of establishing a pattern implicitly by showing it, they instead use a statement to say explicitly what the first explanation is (e.g. the statement “My name is Nobody”). The second explanation then does the Necker shift that makes the joke work.

So, there’s a good case that jokes and stories have an underlying structure that does a job (setting up one set of expectations, and then showing an outcome) and that tends to converge on the most efficient structure (e.g. the 1-2-3 implicit “show” structure or the declarative explicit “tell” structure) and then stay unchanged for long periods.

Closing thoughts

In conclusion:

Physical inventions often reach a plateau, and then stay largely unchanged for a very long time. Even after a new invention supplants them in most of their previous territory, they often remain the best solution for some parts of their previous territory, often for a very long time.

It appears likely that conceptual inventions (ideas that offer explanations, or guidance on how to handle situations) follow the same pattern of reaching a plateau, then staying largely unchanged for very long periods of time, and of clinging on in some areas even if they are supplanted by a new idea in most of their original core territory.

This is an important issue because there’s a widespread tendency to assume that a new invention is better than the previous one in all respects. This can cause problems when people start basing policies on that assumption. For example, smartphones are better than old-style mobile phones in many respects, but there are still some contexts in which old-style mobile phones have advantages. When commercial organisations and governments start basing policies on the assumption that everyone has a smartphone, this will lead to problems for the small but significant number of people who don’t; these problems can be big enough to make a policy unworkable. On a more positive note, knowing about an old technology or concept can let you solve problems that are difficult for new approaches. So, old inventions are often persistent for good reasons, and knowing about these can be very helpful.

Notes and links

Image credits for pointy sticks images:

Modern javelin image: By Ragnar Singsaas – Exxon Mobil ÅF Golden League Bislett Games 2008, CC BY-SA 2.0,

Rifle and bayonet image: By Unknown author – This is photograph Q 70901 from the collections of the Imperial War Museums., Public Domain,

Clacton spear image: By Geni – Photo by user:geni, CC BY-SA 4.0,

Image credits for dodecahedron and kitchen images:

Roman kitchen reconstruction:

By Lazar Pejović – PDF – Published by Ministry of Culture, Sport and Media, Republic of Montenegro, Podgorica, Montenegro- 2007, Public Domain,

Dodecahedrons: By Kleon3 – Own work, CC BY-SA 4.0,

You’re welcome to use Hyde & Rugg copyleft images for any non-commercial purpose, including lectures, provided that you state that they’re copyleft Hyde & Rugg.

You might find our website useful for related resources:




There’s more about the theory behind this article in my book Blind Spot, by Gordon Rugg with Joseph D’Agnese.



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