On the ‘Plausibility’ of the Iliad and Social Networks?

This is a bit of a strange one … my spiders started dragging back versions of this story the other day and it was interesting how different it was being spun depending on which journalist was covering it. The starting point is an article by Pádraig Mac Carron and Ralph Kenna entitled Universal properties of mythological networks (where it can be downloaded for free, after some registration). It’s in a journal called Europhysics Letters and is based on a pile of statistical calculations which are clearly beyond my understanding (and yes, I have read the paper three or four times, maybe even five). However, I can understand argument, which clearly isn’t reflected in the newspaper coverage.  As such, it’s worth beginning with the abstract:

As in statistical physics, the concept of universality plays an important, albeit qualitative, role in the field of comparative mythology. Here we apply statistical mechanical tools to analyse the networks underlying three iconic mythological narratives witha view to identifying common and distinguishing quantitative features. Of the three narratives, an Anglo-Saxon and a Greek text are mostly believed by antiquarians to be partly historically based while the third, an Irish epic, is often considered to be fictional. Here we use network analysis in an attempt to discriminate real from imaginary social networks and place mythological narratives on the spectrum between them. This suggests that the perceived artificiality of the Irish narrative can be traced back to anomalous features associated with six characters. Speculating that these are amalgams of several entities or proxies, renders the plausibility of the Irish text comparable to the others from a network-theoretic point of view.

… which is to say, their purpose is to apply statistical models from social networks to assorted ancient epics, with a view to proving the plausibility specifically of the Irish one. Reading the paper itself actually confirms that they’re trying to lend plausibility to the Irish thing, but most of the coverage that has been presented as of this writing seems to be taking this study in other directions. A comparison of the ‘headlines’ is instructive:

… which must be boggling the minds of the authors of the study, given that not one headline mentions the Irish epic (T’ain)!

That said, we should examine the study … the Scientific Blogging thing mentioned above explains the methodology most clearly:

Pesky humanities types are always butting into science and a new article in EPL (Europhysics Letters) turns the tables. Pádraig Mac Carron and Ralph Kenna from Coventry University performed detailed text analyses of the Iliad, Beowulf and the Táin Bó Cuailnge and found that the interactions between the characters in all three myths were consistent with those seen in real-life social networks. Taking this further, the researchers compared the myths to four known works of fiction — Les Misérables, Richard III, Fellowship of the Ring, and Harry Potter — and found clear differences.

To arrive at their conclusions, the researchers created a database for each of the three stories and mapped out the characters’ interactions. There were 74 characters identified in Beowulf, 404 in the Táin and 716 in the Iliad. Each character was assigned a number, or degree, based on how popular they were, or how many links they had to other characters. The researchers then measured how these degrees were distributed throughout the whole network.

The types of relationships that existed between the characters were also analyzed using two specific criteria: friendliness and hostility.

Friendly links were made if characters were related, spoke to each other, spoke about one another or it is otherwise clear that they know each other amicably. Hostile links were made if two characters met in a conflict, or when a character clearly displayed animosity against somebody they know.

The three myths were shown to be similar to real-life networks as they had similar degree distributions, were assortative and vulnerable to targeted attack. Assortativity is the tendency of a character of a certain degree to interact with a character of similar popularity; being vulnerable to targeted attack means that if you remove one of the most popular characters, it leads to a breakdown of the whole network – neither of these appears to happen in fiction.

“We can’t really comment so much on particular events. We’re not saying that this or that actually happened, or even that the individual people portrayed in the stories are real; we are saying that the overall society and interactions between characters seem realistic,” said Mac Carron.

The first thing we pesky humanities types have to deal with are all the Shakespeare and Harry Potter refs in the newspapers. As part the study, the researcher have a couple of paragraphs applying their methods to Richard III, Les Miserables, Harry Potter, and the Fellowship of the Ring, as well as the Marvel Universe. The purpose is clearly to have some ‘obvious fiction’ to compare things with. The authors concluded in regards to these:

While these networks display the high clustering coefficient that is common to all social networks, the fact that they are all disassortative and are almost entirely connected is perhaps an indication of their societies’ artificiality. In a sense they are too small world to be real.

And so we can continue to be pesky humanities types and proceed to an excerpt from the authors’ conclusions (p. 5 of the online article):

Of the three myths, the network of characters in the Iliad has properties most similar to those of real social networks.It has a power-law degree distribution(with an exponential cut-off), is small world, assortative, vulnerable to targeted attack and is structurally balanced.This similarity perhaps reflects the archaeological evidence supporting the historicity of some of the events of the Iliad .

There is also archaeological evidence suggesting some of the characters in Beowulf are based on real people, although the events in the story of ten contain elements of fantasy associated with the eponymous protagonist. The network for this society, while small, has some properties similar to real social networks,though like all the fictional narratives it is disassortative. However,removing the main character from the network renders it assortative. Thus, while the entire network is not credible as reflecting a real society, we suggest that an assortative subset has properties akin to real social networks, and this subset has corroborative evidence of historicity.

Currently there is very little evidence for the events and the society in the T´ain. While there is some circumstantial evidence in terms of the landscape [44], its historicity is often questioned [39,40]. Indeed, the social network of the full narrative initially seems similar to that of the Marvel Universe perhaps indicating it is the Iron Age equivalent of a comic book. However, comparing the T´ain’s degree distribution to that of Beowulf reveals a remarkable similarity, except for the top six vertices of the Irish narrative. This suggests the artificiality of the network maybe mainly associated with the corresponding characters. They are similar to the superheroes of the Marvel Universe —too super-human to be realistic, or in terms of the network, they are too well connected.

In other words, the ‘plausibility’ of the Iliad — which has some archaeological ‘confirmation’ to it — is confirmed by the ‘social network statistics’, which is actually interesting, but not the point of the study — indeed, given that the authors indicate that they are aware of the possible historicity of some of the events in the Iliad, there would be a dangerous circularity lurking in that argument. Beowulf, with its rather more tenuous archaeological ‘confirmation’, is similarly tenuous on the social network side of things. Finally, the T’ain, with no archaeological support, is also on par with the total fictional world of a comic book. That last thing is the point of the article, despite what the papers say. I guess we pesky humanities types are necessary for translation of serious scientific types’ words …