Analysing inter-state communication dynamics and roles in the networks of the International Institute of Intellectual Cooperation
With Folder A and Folder F networks at hand, we analyse their structure to understand the IIIC’s geographical organisation. Table 1 summarises some basic descriptors of these networks. Worth highlighting, both networks display a high amount of closed triangles \(\left\langle C\right\rangle\) (i.e. triples of nodes connected with each other), and a low average shortest path length \(\left\langle l\right\rangle\) between nodes. The joint presence of both properties is the hallmark of small-world networks (Watts and Strogatz, 1998). Additionally, and despite their sparsity (low ρ), we notice that in both networks the largest connected component, S, comprises the vast majority of the system. Finally, more than 80% of the nodes in both networks have a self-loop. These features highlight the compact and well connected nature of the web of bi- and multi- lateral relationships between countries, as well as the presence of a significant amount of ‘self-communication’.
Going beyond these macro structural features, we are particularly interested in their networks’ community structure. That is, the (possible) existence of modules within the networks emerging from the interaction patterns (Fortunato and Hric, 2016)—as opposed to some predefined partition that results from historical or cultural previous knowledge. With the term ‘community’ (or module) one usually refers to groups of nodes (i.e. countries) more tightly knit with each other than with the rest of the system. In our case, communities could arise from the existence of a shared history (e.g. Scandinavian countries) or from multilateral alliances.
One indicator to quantify how well defined is a network’s community structure is the so-called modularity, \(Q\in \left[0,1\right)\), see Eq. (1) (Newman, 2006) in the Methods section. A large value of modularity (Q ≫ 0) implies the existence of well-defined communities, whereas Q ≃ 0 indicates their absence. Further, once a block partition has been identified from the networks, we focus on the functional role (Guimerà and Amaral, 2005) that each country plays in that community structure (see Methods). The following subsections explore these features.
The hierarchical organisation of the IIIC
We extracted the community structure of our networks using a modularity maximisation algorithm (Traag et al., 2019) (see Methods). The community detection algorithm identified Ncom = 14 communities for Folder A and Ncom = 17 for Folder F, translating into a modularity of Q = 0.242 for Folder A and Q = 0.303 for Folder F, respectively. These values of modularity suggest that our networks do not possess a clear modular structure. However, the visual inspection of the contact matrix plot (i.e. the plots displaying the amount of letters exchanged between countries) displayed in Fig. S6 highlights the existence of a community structure, thus disproving our initial intuition. The disagreement between the low modularity values and observed community structure lays its roots in the presence of two countries, namely France and Switzerland, connected with a significant fraction of other countries.
These countries are, in fact, linked to a vast portion of the system: from the Paris-based IIIC’s archive, France appears to exchange its correspondence with 85% of the countries in both folders, whereas Switzerland is connected to either 68% (Folder A) or 51% (Folder F) of them (see Table S9 of the SM for the details), corresponding to 83% (Folder A) and 73% (Folder F) of the available letters. These figures imply, in practice, that France and Switzerland behave like broadcasters in the system. Historically, this observation makes sense if we consider the role of Paris and Geneva as headquarters of IIIC and the ICIC, as well as the fact that both bodies benefited from Paris and Geneva’s international character to cherry-pick their collaborators. Further, a deeper analysis of the history of IIIC tells us that Paris and Geneva exerted a strong cultural and political influence over the IIIC’s structure, and had an internal dispute over its ruling as well as on the role of intellectual centres (Grandjean, 2022; Renoliet, 1999), going past the mere duplication of communication between these institutions. Structurally, the presence of France and Switzerland connected with a large portion of the other nodes induces a reduction in the values of Q, as the large amount of cross-community links dim the possible underlying modular organisation. In other words, our data analysis so far reflects the widely accepted consensus that Paris and Geneva acted as two competing centres (Grandjean, 2022).
However, it is possible to dig deeper into ICO’s organisation, going beyond the well-known Franco-Swiss dominance. In particular, we are interested in surfacing the underlying flow of communication and emerging structure disregarding these countries’ presence in the system. We do so by pruning France and Switzerland nodes (and their corresponding connections) off the network, and subsequently analysing the remaining graphs, which we denote as Folder A* and Folder F*. Table 1 highlights their main structural features.
A world beyond broadcasters: background flows in the IIIC
Focusing on the structural indicators listed in Table 1 we notice that, despite the removal of the two main hubs, the networks are not dismantled, as the size of their largest connected component, S, decreases only slightly. In fact, 95% of the nodes in Folder A*, and 86% of those in Folder F*, belong to the largest connected component—that is, they remain attached to the bulk of the system.
The community analysis of Folder A* and Folder F* networks reveals—as hinted above—a sharp block organisation. The detachment of France and Switzerland has induced a significant increase in Q, with their values rising from 0.242 (Folder A) to 0.787 (Folder A*), and from 0.303 (Folder F) to 0.676 (Folder F*). These values are statistically validated against a null model, and exclude the possibility that the identified communities are the by-product of mere chance (Guimerà et al., 2004) (see Supplementary Note S2 of the SM). Figures 1a and 2a represent the resulting Folder A* and Folder F* pruned networks, respectively. In them, nodes are coloured according to their identified communities, and node size is proportional to its strength, i.e. the amount of communication that country is involved in. For visualisation purposes, nodes have been placed according to its across-modules communication.
a Graph representing the pruned network Folder A*. Community labels are represented by colour, and node size is proportional to its strength (sent-received correspondence). Some communities reflect historical or geographical affinities, but these alone do not explain the emergence of the structure. b Functional role of countries according to their position in the (p, z) plane for Folder A*. Labels denote the countries’ ISO 3166-1 alpha-3 codes. The colour of points is consistent with community membership in (a). Nodes in the structurally more relevant roles (R3, R5, R6) display a fair amount of diversity (North and Latin America, Western and Central Europe), but Africa and Asia are mostly relegated to peripheral roles (R1, R2).
a Graph representing the pruned network Folder F*. Colour represents community membership, and node size is proportional to strength. As with Folder A*, some communities reflect historical or geographical affinities (Table 2), but that is not the dominant pattern. b Functional role of countries according to their position in the (p, z) plane for Folder F*. The colour of points is consistent with community membership in (a). Nodes in R6 are scarce and geographically homogeneous (in contrast with Folder A*, Fig. 1b). Also in Folder F*, Africa and Asia are mostly relegated to peripheral roles (R1, R2).
To a certain extent, community membership can be easily explained by geographical proximity, cultural affinity, or geopolitical context: so happens with the bulk of Scandinavian countries in Folder A*, gathered in a single community (Fig. 1a, in dim green); or the community dominated by Spain (ESP) and some Latin American countries, which were regrouped in some of the literary projects the IIIC stimulated, visible in Folder F* (Fig. 2a, in red). Beyond these cases, the community structure in both folders (summarised in Tables S6 and S7 of the SM), reveals the existence of a non-trivial organisation. Indeed, most of the emerged blocks can only partially be explained through the canonical view on the relationships between countries during the interwar period: see for example Table 2, showing a possible grouping of countries according to historical expertise, and how it differs from the algorithmically inferred communities. Finally, it is important to remark that communities are quite different from Folder A* to Folder F*. Changes in community membership and/or in position are the norm, rather than the exception. For example, United Kingdom (UK) and United States (USA) are unsurprisingly placed in the same module in Folder A*, but remain quite apart in Folder F*. Colombia (COL), on the other hand, is clearly a connector in Folder A*, but remains quite peripheral in Folder F*. Measuring the similarity between both partitions via the normalised mutual information (Ana and Jain, 2003) and the element-centric (EC) index of Gates et al., (2019) returns 0.64 and 0.29 (out of a maximum of 1), respectively, confirming the impression that communities in Folder A* and Folder F* differ.
These differences reflect a very interesting phenomenon: administrative and bureaucratic communication dynamics (Folder A, and its derived Folder A*) yield a certain structure, which is very different from the one arising from artistic and literary matters (Folder F, and its derived Folder F*). Such differences may be better grasped through functional roles in the context of the identified community structure. Indeed, sociologists have long characterised individual actors by the roles they play in social systems (Merton, 1957). ‘Roles’ here refer to patterns of behaviour associated to positions in a social structure. The network translation of this idea usually relies on the notion of structural equivalence and its looser version, structural similarity: actors playing similar roles will have similar patterns of connections with other actors in a network (Burt, 1976; Lorrain and White, 1971).
Among the operational definitions of roles (González-Bailón et al., 2014; Klimm et al., 2014), we present here the characterisation based on the work by Guimerà and Amaral (Guimerà and Amaral, 2005), assigning roles to nodes based on the analysis of their connections within and across groups/communities (see Methods). For each node i, we compute the z-score of its within-module degree, zi (see Eq. (2), Methods), and its participation coefficient, pi (see Eq. (3), Methods). The former quantifies how many connections one node has with respect to other nodes in the same community, whereas the latter measures to what extent a node’s connections spread across communities. We divided the (p, z) plane into six regions (see Supplementary Note S3 of the SM for a detailed explanation of how we divided the (p, z) plane), each corresponding to a distinct role R. Specifically, nodes can be distinguished as non-hubs (R1, R2, and R3) and hubs (R4, R5, and R6), according to their value of z; and as peripheral (R1 and R4), connector (R2 and R5), and kinless (R3 and R6), according to their value of p (Klimm et al., 2014). Worth highlighting, functional roles are specially suited to bridge all the descriptive levels in a network: they allow to spot a node’s (microscale) position with respect to communities (mesoscale) and the network as a whole (macroscale). In this sense, functional roles provide a richer interpretation than other descriptors, e.g. centrality measures (Wasserman and Faust, 1994) such as closeness or betweenness, which determine a node’s importance in relation to the whole system—regardless of the presence or not of a community structure. Section Supplementary Note S4 in the Supplementary Material delves further in the differences and overlaps among these possible descriptors.
Figures 1 b and 2b show the position of countries (nodes) on the (p, z) plane. For consistency, points follow the same colour code as the graph visualisation on the left. Peripheral nodes in R1 (irrelevant in terms of connectivity and isolated with respect to modules other than their own) have not been labelled, to reduce the visual clutter (see Tables S11 and S12 in the SM for an exhaustive account). For the purpose of illustrating distinct communication dynamics in the folders, we will focus on roles R3, R5, and R6: those which truly glue the network together. In particular, nodes belonging to the R3 and R6 roles are also known as the diverse club (Bertolero et al., 2017). A shallow look to both folders’ (p, z) plane already tells us that R6 in Folder A* is quite populated, compared to Folder F* (the same holds for R3). This means that the effort of maintaining the network connected is more homogeneously spread in administrative correspondence, while literary affairs depend on less (but stronger) actors, especially Italy (ITA), United Kingdom (UK), Spain (ESP), and Belgium (BEL)—the only ones in R6. Geographically, this difference in the connector countries points at a distributed (Folder A*) versus exclusively Western-European (Folder F*) functioning of the system: not only R6 in Folder A* is shared by several countries, but these are more diverse—from Latin America, and East and West Europe and include peripheral actors within the organisation like Colombia and El Salvador. Note that also United States lies at the edge between R5 and R6.
At the other extreme, Figs. 1 and 2 highlight—within the two folders considered by our study,—the extremely peripheral role played by Asian and African countries. This fact can be attributed to unequal power relations in the political domain, which would be the case in colonial or imperial dynamics, as well as to uneven power relations in the intellectual domain. This is the case of most of Africa, the Middle East, and vast portions of Asia. India has only one connection (to United Kingdom) in Folder A*, implying that UK mediated any participation of India in IIIC’s governance. India does not even appear in Folder F*’s network. Turning to China, we see it plays a bridging role as a kinless non-hub in Folder A* (R3), and as a peripheral hub (R4) in Folder F*. Japan, still lagging centuries of isolationism and upset with the outcome of the Treaty of Versailles, appears to be marginal in both folders’ graphs.
Said findings do not coincide with Saikawa’s conclusions on the role of China and Japan in the history of intellectual cooperation, a work written with a focus on the ICIC, rather than on the IIIC (Saikawa, 2014). This discrepancy points, in turn, to the need of further research, as well as the need to combine different archival records to fully decentring the history of intellectual cooperation.
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