Rethinking the International System As a Complex Adaptive System

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A New Taxonomy for International Relations: Rethinking the International System as a Complex Adaptive System

Scartozzi, Cesare M.

University of Tokyo, Graduate School of Public Policy

2018

Online at https://mpra.ub.uni-muenchen.de/95496/ MPRA Paper No. 95496, posted 12 Aug 2019 10:50 UTC 1SFQVCMJDBUJPOJournal on Policy and Complex Systems • Volume 4, Number 1 • Spring 2018

A New Taxonomy for International Relations: Rethinking the International System as a Complex Adaptive System

Cesare Scartozzi Graduate School of Public Policy, University of Tokyo

[email protected] 7-3-1, Hongo, Bunkyo, Tokyo 113-0033, Japan ORCID number: 0000-0002-4350-4386.

Abstract The international system is a complex adaptive system with emergent properties and dynamics of self-organization and information processing. As such, it is better understood with a multidis- ciplinary approach that borrows methodologies from the field of complexity science and integrates them to the theoretical perspectives offered by the field of international relations (IR). This study is set to formalize a complex systems theory approach to the study of international affairs and introduce a new taxonomy for IR with the two-pronged aim of improving interoperability between different epistemological communities and outlining a formal grammar that set the basis for modeling international politics as a complex adaptive system. Keywords: international politics, international relations theory, complex systems theory, taxonomy, adaptation, fitness, self-organization

This is a prepublication version of: Scartozzi, Cesare M. “A New Taxonomy for International Relations: Rethinking the International System as a Complex Adaptive System.” Journal on Policy and Complex Systems 4, no. 1 (2018): 109–33. https://doi.org/10.18278/jpcs.4.1.6.

doi: 10.18278/jpcs.4.1.6 109 Journal on Policy and Complex Systems Una nueva taxonomía para las relaciones internacionales: repensando el sistema internacional como un sistema adaptativo complejo

Resumen El Sistema internacional es un sistema adaptativo complejo con propiedades emergentes y dinámica de auto organización y pro- cesamiento de información. Como tal, es mejor comprender con una aproximación multidisciplinaria que extraiga metodologías del campo de la ciencia de la complejidad y las integre a las pers- pectivas teóricas ofrecidas por el campo de las relaciones internacionales (RI). Este estudio existe para formalizar un acercamiento teórico de sistemas complejos para el estudio de los asuntos internacionales y presentar una nueva taxonomía para las RI con el objetivo bipartito de mejorar la interoperabilidad entre diferentes comunidades epistemológicas y esquematizar una gramática formal que ponga las bases para los modelos de las políticas internacionales como un sistema adaptativo complejo. Palabras clave: política internacional, teoría de relaciones internacionales, teoría de sistemas complejos, taxonomía, adaptación, aptitud, autoorganización

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110 Rethinking the International System as a Complex Adaptive System

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Introduction could use the vast array of positivist and post-positivist theories in a coherent his study puts forward the idea and integrative way, we would be finally that the international political able to make sense of the multifaceted Tsystem is a complex adaptive sys- inquiries of international politics. But tem, with emergent properties and dy- in reality, coherence is hard to achieve namics of self-organization. Hence, it when confronted with an overarching suggests that the international system and disorganized menu of theories and is better understood with a multidisci- claims. And without coherence and plinary approach that borrows meth- method, the whole discipline becomes odologies from the field of complexity prone to relativism and loss of critical science and integrates them with the standards (Dunne et al., 2013, p. 415), theoretical perspectives offered by the transforming academic dialogue in an field of international relations (IR). The empty debate of perspectives and mir- overall scope of this study is to formal- rors. ize a complex systems theory approach A more fundamental problem to IR, define a new taxonomy for the that affects both general theories and discipline to improve interoperability pluralist approaches of IR is a lack of between different epistemological com- understanding of the subdued nonlin- munities, and set the basis for future earity of social, and therefore political, modeling of the international system as interactions among agents. For long, a complex adaptive system (CAS). scholars thought they were looking at IR scholars have embraced the- international politics, but instead, they oretical diversity over the past decade were only looking at its linear, constant, and acknowledged the validity of a continuous, and deterministic image. wide range of different theoretical per- Theorists did not realize (at least most spectives in the realm of foreign poli- of them) that there was another image cy. Many have welcomed theoretical of world politics. That image is non-lin- pluralism as a positive development ear, discrete, stochastic, and composite: for the discipline. Dunne, Hansen, and a chaotic face of the world where there Wight (2013, p. 416) argued that if we are no general laws or causalities.

111 Journal on Policy and Complex Systems

At large, IR scholars have de- post-modern and post-structural the- ceived themselves and only saw what ories, like constructivism, ended up they were already acquainted with. In rejecting the image of an objective and the picture of social systems and inter- “external world” to focus on the observ- national politics, they saw the image of er or “subjective self” (Smith et al., 2008, linearity (Richards, 2000a, p. 3). Con- p. 30). Yet, by doing so, they focused on sequentially, they blindly used positiv- ontology and overlooked epistemology, ist approaches to come up with general leaving the task of the interpretation to theories based on inductions and de- the subjective, and biased, self (Smith et ductions rooted in a simple and linear al., 2008, p. 18). image of the world. However, the real Offering an alternative to general world has never been linear and it has theories or pluralism, this paper sug- rarely fitted within the general laws and gests that the complexity of politics can causalities found by social scientists. only be unraveled using an interdisci- Repeatedly, new trends and unexpect- plinary research method that incorpo- ed events have confuted IR theories and rates complex systems theory with IR: required us to seek for new correlations. a method that allows for an ontological Eventually, the discrepancy between closure between the ‘real world’ and the the real and the theoretical became so world of our theories. The consequence vast that IR theorist started to look for of this closure is exciting as it implies new epistemologies beyond positivism that we can advance our knowledge of during the eighties. international politics by making more Unfortunately, the pursuit for detailed and holistic analyses of the in- a new epistemology in IR resulted in ternational system that do not rely on a twofold failure. First, it failed to re- oversimplifications for modeling. The place empiricism, which far from being methodology put forward by this study dead is even experiencing a resurgence does not fixate on one specific level in narrow scope quantitative research of analysis, but instead focuses on the (Mearsheimer & Walt, 2013). Second, it multilevel nature of nonlinear dynam- failed in finding a coherent epistemolo- ics in the international system to find gy capable of dealing with the nonlinear theoretical insights and explain the re- ontology of social systems and interna- lationships between agents and system tional politics. Scientific realism and behavior (Downey, 2012, p. 92). In- critical theory were still fixated on the stead of arbitrarily defining the agents same linear world that positivist looked of the international system and assum- at. By assuming that the natural and the ing how they behave, it assumes what social worlds were governed by equal are the properties of agents (autono- and objective recurrencies, scientif- my, self-containment, and interdepen- ic realism and critical theory recurred dence) and how behavior is generated to a positivist epistemology to study (through the processes of performance international politics (Smith, Booth, system, credit assignment, and rule dis- & Zalewski, 2008, p. 35). Conversely, covery).

112 Rethinking the International System as a Complex Adaptive System

Over the last two decades, sever- Only pluralism can deal with a al attempts have been made to use com- multi faceted and complex reali- plex systems theory to analyze interna- ty and only pluralism can deliv- tional politics, see for instance Robert er substantial progress in terms Axelrod’s The Complexity of Cooperation of knowledge. Given the lack of (1997), Neil E. Harrison’s Complexity in agreed epistemological standards World Politics (2006a), Diana Richards’ for assessing competing knowl- Political Complexity (2000b), and Emil- edge claims, we should embrace ian Kavalski’s “The Fifth Debate and the all perspectives. [ ... ] Our view Emergence of Complex International is that we should attempt to Relations Theory” (2007). Yet, only a move towards a position we will handful of IR scholars have advocated term ‘integrative pluralism’. [ ... ] for the use of complexity theory as an Integrative pluralism accepts and overarching theoretical framework of preserves the validity of a wide IR, and fewer among them have used range of theoretical perspectives its modeling techniques to study the and embraces theoretical di- international system. This article hopes versity as a means of providing to fill a gap in the literature by posing more comprehensive and multi the taxonomical foundations of a theo- dimensional accounts of complex retical framework of IR rooted in com- phenomena [emphasis added]. plexity theory. Overall, this study is set (Dunne et al., 2013, p. 417) to offer a radical reinterpretation of the way we think of international affairs by However, there is an inconsisten- proposing new ontological, epistemo- cy in this argument: a sum of not-good- logical, methodological, and taxonom- enough theories does not make for a ical perspectives. good enough theory. Traditional IR theories are just not equipped with the Where Does Complexity necessary epistemology and method- Theory Stand? ology to make sense of complex adaptive systems. Pluralism, in this case, he fourth inter-disciplinary can only lead us to a plurality of errors debate between positivist and and misinterpretations. Sure, the more Tpost-positivist scholars has theories we use, the more likely we are succeeded in moving out IR from a to find a tangential explanation for our strictly positivist ground,1 but it has phenomenon of interest, but none of failed in creating cohesion over a new those explanations will be able to grasp philosophical system. On theoretical the core dynamics of the internation- pluralism, Dunne, Hansen and Wight al system (adaptation, emergence, and wrote: self-organization). For this reason, we

1 There has been a tendency among theory-leaden positivist scholars to shift toward post-positivism, this is the case for example of John Mearsheimer, which in a paper in 2013 wrote that scientific realism offers “a more convincing epistemology” (Mearsheimer & Walt, 2013, p. 433).

113 Journal on Policy and Complex Systems should start using complex systems the- support his own arguments; even ory also in IR. though his arguments were unsup- Moreover, complex systems the- ported from the epistemological and ory has the potential of reestablishing methodological standpoints of com- 3 agreed-upon epistemological stan- plex system theory. dards and promotes consilience in the It appears that Wendt and many field of IR. It does so as a non-positivist other post-positivists in IR have, to theoretical framework that integrates some extent, grasped the nonlinearity concepts and methods used by both of social systems. However, they missed positivist and post-positivist schol- to follow through the study of nonlin- ars. Where positivist implemented an earity with the appropriate modeling “outside view” of social sciences and methods and instead used hermeneutic post-positivist an “inside view” of it, and subjective analyses. This trend is complexity theory integrates the two pitiful because the computational tech- views into an “inside-out” ontology that niques offered by complex system the- takes account of the nonlinear dynam- ory and agent-based modeling would ics that occurs between agents and sys- have allowed them to make large-scale tem in international politics (Harrison models of system dynamics generated & Singer, 2006, p. 38). bottom up using the “inside view” that Notwithstanding its potential, they favor. IR scholars have largely ignored or In sum, whereas positivist schol- misused complexity science. Often, ars bluntly ignored nonlinearity in in- scholars have sloppily borrowed and ternational affairs, post-positivists ig- decontextualized its taxonomy. This nored the methodologies and analytical is, for instance, the case of Dunne et tools that could be used to study it. Con- al. (2013), who, without ever men- sequently, both scholarships “missed tioning complexity theory, defined a lot” by not being able to observe or the international system as a CAS.2 explain the emergent global dynamics Another scholar that misused com- resulting from nonlinear interactions plexity theory is Alexander Wendt of composite agents in the international (1987, 2003), who decontextualized system (Richards, 2000a, p. 2). As Di- complexity theory as an analogy to ana Richard (2000a) wrote:

2 Dunne et al. give a definition of the international system that seems taken from a complexity theory textbook: “contemporary international political system is best understood as a complex open system, which displays ‘emergent properties’ and degrees of ‘organized complexity.’” Yet, they never mention complexity theory in their paper, and instead advocate that “integrative pluralism” is the most appropriate research framework to study complex systems (Dunne et al., 2013, p. 417). 3 Wendt develops his arguments using, and decontextualizing, a taxonomy drawn from complexity theory. For instance, he refers to emergence, self-organization, negative and positive feedbacks, upward causation, boundary conditions, etc (Wendt, 1987, p. 369; Wendt, 2003, p. 498). However, he does so without using the epistemological framework of complexity theory. Moreover, his studies do not use any form of computational modeling, which is a standard methodological practice to study CAS (Earnest & Rosenau, 2006, p. 145). For these reasons, Wendt’s interpretation of the international system as a CAS appears to be subjective and dogmatic.

114 Rethinking the International System as a Complex Adaptive System

No wonder very few clear em- Lack of cross-contamination pirical relationships have been among the communities is thus fostered found over decades of political by a lack of understanding among them. science. If it is a nonlinear world An effort of “translation” among taxon- and we are looking with “linear omies has been attempted in the book vision,” then we can only catch a Complexity in World Politics: Concepts small portion. Furthermore, our and Methods of a New Paradigm, edited models of constant effects will by Neil E. Harrison (2006a). Where the miss something fundamental first two chapters, written by Harrison about what we are studying; as and Singer, provide a seminal taxono- the saying goes, it’s like throwing my of complexity science for the use of a dead bird to model the flight of social scientist. However, communica- a live bird. (p. 2) tion is not the sole impediment to the spread of complexity theory in IR. The As this paper advocates, it is time discipline is also divided among meth- for IR to stop missing out. Hence, the odological communities. The divisions need for IR to embrace complex sys- are furthermore aggravated by the fact tems theory, pose much-needed onto- that, as Richards (2000a) writes, meth- logical and epistemological questions, odologists are known to “suffer change,” and develop a new taxonomy that will especially when they are too comfort- improve interoperability between dif- able with their own methods (p. 3). ferent epistemological communities As it is today, the IR literature that and provide the basis for nonlinear has used complexity science is mainly modeling in IR. found in the book series titled Princeton IR is a discipline that tradition- Studies in Complexity, and in two col- ally does not shy away from importing lections of essays; the above-mentioned theories from other fields of studies.4 Complexity in World Politics, and Po- Nevertheless, there has been only limit- litical Complexity: Nonlinear Models ed cross contamination with the field of of Politics edited by Richards (2000b). complexity theory. Arguably, lack of di- Complexity in World Politics collects alogue and interdisciplinarity has large- ten papers, including: An introductory ly been caused by a linguistic cleavage article by Harrison and Singer (2006) among different epistemological com- that compares IR systems theory with munities in the discipline. It appears complex systems theory. An essay on that while all communities deal with conflict resolution by Dennis Sandole the same field of study and use the same (2006) that uses complexity to reconsid- language, each of them has a different er “theories of identity-based conflict in cognitive understanding of concepts, the post-9/11 world.” A paper by Walter terms, and vocabulary. Clemens (2006) that uses complex sys-

4 IR has borrowed political theory, philosophy, and history from the humanities; economics, sociology, and law from other social sciences; and math, physics, and statistics from natural sciences (Dunne et al., 2013, p. 419).

115 Journal on Policy and Complex Systems tems theory to explain why only a few coauthored books, Generative Social (and fit) ex-Soviet states were able to Science, Agent Zero, and Growing Arti- integrate into the EU. An insightful es- ficial Societies. Epstein’s trilogy provides say by Matt Hoffmann (2006) that stud- a foundational framework for study- ies coevolution and adaptations in the ing social dynamics with agent-based context of the creation of international modeling. The book Growing Artificial regimes. An agent-based model by Ravi Societies uses complex systems theory Bhavnani (2006) on the spread of vio- in a holistic way to recreate in silico an lence in the 1994 Rwandan genocide. entire society made of composite agents In addition, lastly, a chapter written by that, with a distributed artificial intelli- Robert Axelrod (2006), which ponders gence, reproduce, create, consume and the role of simulation in IR and social trade resources. The book is particu- sciences vis-à-vis traditional inductive larly relevant because it provides case and deductive methods. studies on how to “discover fundamen- The book Political Complexity tal local or micro mechanisms that are is instead focused on political science sufficient to generate the macroscopic and only few of its chapters touch upon social structures and collective behav- international relations. Among those iors of interest” (Epstein & Axtell, 1996, who do, are worth mentioning: Rich- pp. 12–16). ards’ (2000a) paper on nonlinear mod- While there is a growing body eling, which reframes political science of literature in social sciences that uses under a complexity theory framework, complexity science, the largest body and her paper on nonlinear dynamics is still found in natural and computa- in games, which provides an example tional sciences (Henrickson & McK- of modeling for international environ- elvey, 2002). Fortunately, due to the mental regimes. interdisciplinary nature of complexity The Princeton Studies in Com- science, each theoretical advancement plexity Series has published 14 full- in a discipline quickly translates to an length books on complexity theory that overall progress for all the others. For ranges from biology to economics and instance, the contribution of Stuart A. political science. Those of particular in- Kauffman’s (1993) seminal book titled terest for the field of IR are: Axelrod’s The Origins of Order goes beyond the (1997) book The Complexity of Coop- field of evolutionary biology and invests eration, which uses agent-based mod- any scholar that uses complexity theo- eling and genetic algorithm to study ry. A social scientist might as well find cooperation and meta-norms. Lars-Er- in Kauffman’s elegant use of modeling ik Cederman’s (1997) book Emergent techniques a source of inspiration for Actors in World Politics, which reviews modeling social dynamics. Similarly, traditional IR scholarship and simulates John H. Holland’s (1995) book Hidden state formation and “balance of power” Order introduces computational tech- in complex adaptive systems. And Josh- niques that have been used in several ua M. Epstein’s (1996, 2007, and 2013) fields of study and for different purpos-

116 Rethinking the International System as a Complex Adaptive System es, including the modeling of aggregate warrant and methodologies, they will social behavior to the development of be able to study the international sys- artificial intelligence. Among the most tem for what it really is: a system that recent scholarship focused on the study lacks centralized control and that is of CASs are also worth mentioning composed of a large number of adaptive Nino Boccara (2004), Claudius Gros agents interacting in a nonlinear fash- (2011), and Allen B. Downey (2012), ion that gives rise to emergent behavior who have published very informative and principles of self-organization. books focused on modeling techniques from mathematical and computation- Concepts and Ideas for a New al perspectives. These books, together Methodological Approach to IR with Uri Wilensky and William Rand’s (2015) An Introduction to Agent-Based omplexity science aims to de- Modeling, provide a comprehensive velop cross-disciplinary insights overview and a good groundwork for Cinto complex systems by using any research project that tries to study a methodology that is a combination the international system using complex of experimental, theoretical, and com- systems theory. puter simulation (Mitchell, 2015a). Only a handful of scholars have Complex systems, which can be either advocated for the use of complexity the- complex adaptive systems (CASs) or ory as an overarching theoretical frame- complex physical systems (CPS), are work of IR, and fewer among them have studied in several different disciplines, used its modeling techniques to study including evolutionary biology, immu- the international system. Those who nology, genetics, information science, did, however, have succeeded in tack- dynamics, economics, and sociology. ling fundamental issues of international To define a complex system, it is affairs, such as the creation of interna- better to put aside the concept of com- tional regimes, cooperative behavior plexity, and, as Holland (2013, Chap- and the emergence of nation-states (e.g. ter 1) and Boccara (2004, p. 4) suggest, Axelrod, 1997; Cederman, 1997; Har- focus on the properties of the system. rison, 2006a). Yet, while their findings Complexity comes in many different have been widely acclaimed, their theo- forms and shapes, and different disci- retical frameworks and methodologies plines tend to have different definitions have never gone mainstream among IR and measurements of complexity.5 Nev- scholars. As advocated in this section, ertheless, most complex systems share it is time for IR scholars to go beyond the same properties of nonlinearity, analogies on complexity and realize emergent behavior, self-organization, that the international system is a com- and information processing. Hence, plex adaptive system. Only then, under a complex system can be defined as a complexity theory’s epistemological “system composed of a large number of

5 As Seth Lloyd has catalogued, there are more than 40 different measures of complexity, among which: Shannon information, the degree of hierarchy, and schema length (Lloyd, n.d.).

117 Journal on Policy and Complex Systems interacting components, without cen- where systems change following trajec- tral control, whose emergent ‘global’ tories that appear to be random (Mitch- behaviour—described in terms of dy- ell, 2009, p. 32). As it has been proved, namics, information processing, and/ even a simple and deterministic equa- or adaptation—is more complex than tion as the logistic map, which is used can be explained or predicted from un- to describe population growth in the derstanding the sum of the behavior presence of overcrowding, can lead to of the individual components” (Santa chaotic behavior even if its parameters Fe Institute, n.d.). Some of these prop- are determined exactly. As it can be in- erties, as lack of central authority, are ferred, sensitive dependence on initial self-explanatory, but others deserve to conditions renders perfect prediction be briefly explained. in modeling impossible in principle be- Nonlinearity in mathematics cause variables cannot be measured “to implies nonadditivity (Boccara, 2004, infinitely many decimal places” (Mitch- p. 56). A linear system is one that can ell, 2009, p. 33). be inferred “by understanding its parts Emergent behavior is as well re- individually and then putting them to- lated to the principle of nonlinearity. gether,” but “a nonlinear system is one Emergent properties can be defined as in which the whole is different from “global-level attributes of a system that the sum of the parts” (Mitchell, 2009, arise from the interactions of the com- pp. 22–23). Hence, nonlinear relation- ponents of the system, and that are not ships between agents in a system imply explainable by the behavior of individ- “that an independent variable does not ual components of the system or the have a constant effect on the dependent sum of the components acting as indi- variable” (Richards, 2000a, pp. 1–2). viduals” (Santa Fe Institute, n.d.). It is Nonlinearity is also closely related to important to underline that emergent the concept of sensitive dependence on properties at the systemic level are an initial conditions and chaotic behavior. outcome of the nonlinear interaction of The idea ofsensitive dependence agents, and not of the agent’s properties on initial conditions was first formalized (Boccara, 2004, p. 97). Hence, knowing by the mathematician Henri Poincaré the rules to which agents obey is not at the end of the nineteenth century. enough to predict the behavior of the Poincaré noticed that the initial config- system. The system is computationally urations of a system play a determining irreducible, and, for this reason, CASs role in setting the subsequent states of has neither reductionist explanations the system, and “when the sensitivity is nor yield to compact forms of represen- high, slight changes to starting condi- tations (Mitchell, 2015a). tions will lead to significantly different Self-organization, as defined by conditions in the future” (Santa Fe In- Melanie Mitchell (2015b), is itself an stitute, n.d.). Systems with sensitivity to emergent phenomenon, which can be initial conditions often manifest chaotic described as the “production of orga- behavior, which is a specific dynamic nized patterns, resulting from localized

118 Rethinking the International System as a Complex Adaptive System interactions within the components of Complexity theory follows a third way the system, without any central con- of doing science between induction and trol.” In other words, self-organization deduction.6 By relying on computation- creates stable macroscopic patterns al simulation, it deductively sets axioms arising from the local interaction of and generates data that can be studied agents with limited information and inductively (Harrison, 2006b, p. 139). computational power (Epstein & Ax- Since CASs are irreducible, scholars ul- tell, 1996, p. 35). One generic pattern of timately need the assistance of simula- self-organization is the one of “self-or- tion to be able to explain those (Earnest ganized criticality,” which implies “that & Rosenau, 2006, p. 145). from any initial condition, the system To conclude, studying complexi- tends to move toward a critical state, ty does not require a paradigm shift in and stay there, without external con- the way IR is studied. However, it does trol” (Bak, Tang, & Wiesenfeld, 1987, require some change in the criteria that p. 381; Downey, 2012, p. 81). Self-orga- scholars use to observe the world and nization, as it will be further explained build theories. When scholars model later, requires the system to signal and complexity, they need to shift from con- process information. tinuous to discrete, from linear to non- If we want to define the interna- linear, from deterministic to stochas- tional system as a CAS, we can say that: tic, from abstract to detailed and from the international system is composed homogeneous to composite (Downey, of many diverse, interconnected, and 2012, p. 4). In addition, also their pur- interdependent agents that iterate non- poses in research have to change; stud- linear relationships from which mul- ies should be explanatory and not nec- tilevel behavior evolves and emerges. essarily predictive, models should be Because of non-linearity, lack of cen- instrumental and not realist, and the- tral coordination, and the presence of ories should be holistic rather than re- lever points—the international system ductionist (Downey, 2012, p. 4). should not be studied with traditional positivist methodologies that assume linearity (Holland 2013, Chapter 3). For a New Understanding Positivist theories are built inductively of International Relations or deductively, with the previous dis- covering patterns in empirical data, and A New Grammar and Taxonomy the latter specifying a set of axioms and Ontology and epistemology dictate testing them (Harrison, 2006b, p. 139). what can be classified in a taxonomy,

6 “But unlike deduction, simulation does not prove theorems with generality. Instead, simulation generates data suitable for analysis by induction. Nevertheless, unlike typical induction, the sim- ulated data come from a rigorously specified set of assumptions regarding an actual or proposed system of interest rather than direct measurements of the real world. Consequently, simulation differs from standard deduction and induction in both its implementation and its goals. Simulation permits increased understanding of systems through controlled computational experiments” (Ax- elrod, 1997, p. 4).

119 Journal on Policy and Complex Systems and methodology helps to shape the under the grammar’s rules” (Holland, semantics of the language spoken in a 2013, Chapter 6). Only with this formal discipline. For this reason, positivism, grammar, Holland argues, it is possible constructivism, and complex systems to deconstruct and understand com- theory held a different cognitive under- plex adaptive systems. standing of basic IR concepts. They use, Through deconstruction, a sys- in other words, different semantics and tem can be divided into Lego-like parts, taxonomies. also called building blocks, which serves The scope of this section is two- as generators that can be put together pronged: defining a taxonomy of IR to yield different emergent states of the rooted in the propositions of complex system (Mitchell, 2009, p. 110). In the systems theory to improve interopera- spirit of Descartes’ (1637) treatise Dis- bility between different epistemological course on the Method, the aim of decon- communities, and outlining a formal structing a system into building blocks grammar to set the basis for modeling is “to divide all the difficulties under the international system as a CAS. It examination into as many parts as pos- is necessary to update IR’s taxonomy sible, and as many as were required to because the discipline has no standard solve them in the best way” (p. 17). In language for analyzing the agent ac- the study of CASs, the difficulties are the tions that construct the international emergent properties, and the parts are system.7 Actions that are driven by con- the building blocks. cepts, such as adaptation and coevolu- However, knowing what the tion, which are novel to IR and have yet parts of a system are is not enough to to be systematically contextualized. explain how a system behaves. The ag- In addition, a well-defined tax- gregate properties of the international onomy and grammar are also needed to system, such as migration and war, are standardize a language that is both ca- “not well-described by summing” or av- pable of describing emergent phenom- eraging the acts and properties of sin- ena and at the same time following a gle individuals (Holland, 2013, Chapter syntax suitable for computational mod- 6). This is because emergent behaviors eling. As Holland (2013) suggests, a for- do not arise from the proprieties of the mal grammar for studying CASs should building blocks, but instead from the be composed of “a set of generators (e.g. iteration over time of adaptive interac- a vocabulary), and a set of operators for tions between agents (Mitchell, 2009, p. combining the generators into mean- 6). Knowing the generators of a system is not enough to understand aggregate ingful strings (e.g. sentences)” (Chapter behavior. Instead, we need to know how 6). The purpose of the grammar is “to the generators are combined together to generate a corpus (set) that describes yield emergent behaviors. the states (sentences) that can occur 7 As pointed out in the first section, this is true for positivism, but only partially true for post-modern theories of IR. As it was shown, some constructivists take into account the interactions between agents. Indeed, some of the concepts that they use resembles others of complexity theory. Neverthe- less, the two epistemological communities still have different semantics (Holland, 2013, Chapter 1).

120 Rethinking the International System as a Complex Adaptive System

In conclusion, decomposing a la The first property of an agent Descartes is useful only if the decon- is autonomy (Macy & Willer, 2002, p. struction is orderly and descriptive of 146). An agent, by definition, exists the agent actions that construct the in- autonomously from the system. It pos- ternational system. Hence, the purpose sesses unique internal states and rules of a formal grammar is to conduct our of behavior that allow him to operate thoughts, and modeling procedures, in autonomously with the environment a given order that is representative of and with other agents (Epstein & Ax- the nonlinearity of the system,8 with the tell, 1996, p. 5). The second proper- aims being logical clarity and interoper- ty is self-containment. An agent has to ability with the syntax of programming be bounded, identifiable, and discrete languages used for agent-based model- (Macal & North, 2009, p. 87). The third ing (ABM). property is interdependence. Agents’ in- The following sections serve to ternal states and rules of behavior are provide an overview of IR based on continuously evolving and adapting complex systems theory. The next three through interaction with other agents sections will individuate the generators and the environment. Interdependence of the international system, explain is also tied to the concepts of adaptation, how these generators combine to yield coevolution, and fitness. Beyond these together emergent behaviors, and infer general properties, there is also a wide- what these emergent behaviors entail spread consensus that agents should be for the international system. adaptive, which means that they should change their internal stimulus-response Generators: Agents and the rules based on a process of learning or Translevel Nature of International evolution (Macy & Willer, 2002, p. 146). Relations Agents act, think, and process information autonomously based on The concept of agent is instrumental their internal states and rules of behav- and is used to identify the foundational ior. Internal states are the attributes of building blocks of a CAS. Like any other an agent. Humans, for example, have building block, an agent is a generator many attributes that define them, such whose properties and interactions give as genes, physical properties, economic rise to aggregate behavior. Depending preferences, political identity, wealth, on the discipline, scholars tend to have and skills (Epstein & Axtell, 1996, p. different definitions of what an agent 4). Rules of behavior are an assortment is; however, there are a few common of simple stimulus-response rules that properties that can be traced among the determine in which ways an “agent can scholarships. change the state of the environment, 8 This argument differs drastically from the Descartes’s view, which claims that the purpose for deconstruction is “to conduct my thoughts in a given order, beginning with the simplest and most easily understood objects, and gradually ascending, as it were step by step, to the knowledge of the most complex; and positing an order even on those which do not have a natural order of prece- dence” (Descartes, 1637, p. 17).

121 Journal on Policy and Complex Systems other agents, or itself” (Wilensky & In other words, thinking in terms Rand, 2015, p. 209). We can think of of adaptive agents requires us to consid- each rule as characterized by a receptor er the international system as a complex IF and an executor THEN. To make an whole. A whole that cannot be divided example, if there is an election, a citizen into levels of analyses, as IR scholars will use the detector “IF today is an elec- often like to do. As Wilensky and Res- tion day” to execute the effector “THEN nick (1999) wrote, levels of analysis are go to vote.” The rule could also be more used to provide three different kinds precise and use multiple detectors and of views: organization-chart view, con- effectors at the same time. Because of tainer view, or emergent view. The first adaptive learning, agents do not always one is used to think of structural hierar- execute the same rule when faced with chies within institutions, companies, or the same input; instead, they learn from organizations. Levels, in this case, serve their past and “change their behavior in to conceptualize chains of command the future to account for this learning” and organization-charts. The contain- (Wilensky & Rand, 2015, p. 230). er view, widely used in IR scholar- To understand system-wide be- ship, “is based on the idea of parts and havior, it is essential to have a clear un- wholes” (Wilensky & Resnick, 1999, p. derstanding of the granularity of the 5). This view “differs from the organiza- system, which is composed of agents, tion-chart view” because “the lower-lev- meta-agents, and sub-agents,9 with el elements are parts of the higher-level agents being the fundamental genera- elements” (Wilensky & Resnick, 1999, tors of the emergent behavior of inter- p. 5). For example, a month is part of a est. Meta-agents can be quasi-bounded year (container view), but an employee and possess certain degrees of autono- is not part of the employer (organiza- my; however, their behavior can only tion-chart view). be inferred as an outcome of agents’ The third view is similar to the actions and interactions (Harrison, container view but focuses on “levels 2006a, p. 9). For example, the behavior that arise from interactions of objects of a nation-state in the international at lower levels” (Wilensky & Resnick, system cannot be inferred outside of 1999, p. 5). The difference between the context that has generated it. Social emergent and container view is subtle. organizations are neither self-contained After all, one might argue that just as a nor autonomous. They are meta-agents week is made of days, a state is made of generated by the primary agent of social people. However, the state–people rela- systems: humans. In turn, agents are in- tionship is significantly different. For a terdependent , and their behavior can start, the composition of the state keeps only be understood from a system-wide changing; people leave, come, and die, perspective that takes into account co- so do companies, organizations, institu- evolutionary dynamics. tions, and laws. Furthermore, the state

9 Agents are composed of sub-agents, and meta-agents are composed of agents. In agent-based modeling, it is often said that “it’s agents all the way down” (Wilensky & Resnick, 1999, p. 1).

122 Rethinking the International System as a Complex Adaptive System

“arises from interactions among” the the international system without con- people, and it is not just a simple accu- sidering how it has emerged from it the mulation of people (Wilensky & Res- lower levels of interactions among the nick, 1999, p. 5). As Wilensky and Rand people. (1999) argued, “months do not interact To conclude, by conceptualiz- to form a year; they simply accumulate ing international relations in terms of or ‘add up.’ A year can be viewed, essen- levels of analysis as container views, tially, as a long month” (p. 5). However, IR scholars have repeatedly fallen into a state is not just a big person. The dif- the trap of “slipping between levels to ference is qualitative (Wilensky & Res- attribute properties of one level to an- nick, 1999, p. 5). other” (Wilensky & Rand, 2015, p. 13). IR theory has largely relied on Idealists and realists slipped from the a container view of the international individual to the aggregate by giving systems. Usually, dividing the system human attributes to the state (e.g. states into three arbitrary level of analysis: have national interests and are power the individual level, the state level, and seeking). Neorealist slipped from the the international level. These levels, aggregate to the individual by deriving also called images, have been used by the properties of states from the anar- scholars to study the phenomena of interest in isolation from the rest of the chic international system (e.g. states components of the system (Wilensky & have to self-help and are security max- Resnick, 1999, p. 5). However, by isolat- imizers). Both cases are an example of ing a single phenomenon in a level of the failure of integrative understanding, analysis, scholars lose the ability to see which bars to see states as meta-agents the emergent view and individuate the qualitatively different from the agents micromechanisms that are sufficient that compose them (people) and the to generate the macroscopic behavior environment that they inhabit (interna- of interest (Vicsek, 2002, p. 131). This tional system). happens because these mechanisms are the outcome of cascading effects and Operators: Adaptation, the Higher chains of causalities that move from the Order Rule of International micro to the macro, or vice versa, and Relations therefore, can only be grasped through a multilevel perspective. Consequently, Adaptation occurs at the agent level complex system theory breaks the dis- through learning and at a systemic level tinction between the realm of domestic through evolution. Overall adaptation and international politics. International goes in hand with coevolution. The in- politics is the outcome of the interac- ternal attributes and rules of behavior tions of agents and meta-agents at the of an adaptive agent constantly change domestic and at the international level. through interaction with the environ- Hence, it is not possible, as explained ment and with other agents. As Hoff- in the previous section, to understand man explains:

123 Journal on Policy and Complex Systems

When some agents change their other computational models. Agents behavior, this alters the system are adaptive if they can perform three for the other agents. A new con- procedures: performance system, credit text “forces” agents to alter their assignment, and rule discovery (Hol- rule models as the context deter- land, 1995, p. 42). These procedures, mines what goals, interests, and which happen naturally and often un- behaviors are appropriate or fit. consciously in humans, are useful for Adaptive agents are always trying the scope of this paper to describe how to “fit” with their context.When adaptation occurs at large. their internal rule models fit their The performance system proce- context, the agents are successful. dure has already been introduced in the When their rules do not fit, the previous section in the form of internal agents are not successful. System attributes and rules of behavior. To re- change results when innovation cap, a performance system “specifies on the part of a subset of agents the agent’s capabilities at a fixed point throws the system rules into flux in time” and what an agent “could do in and other agents then adapt their the absence of any further adaptation” rule models and therefore their (Holland, 1995, p. 88). In the words of actions and interactions. [ ... ] Hoffmann, the internal attributes and The system rules, produced by rules of behavior: agent actions and interactions, do more than constrain potential Represent the agent’s internal (or actions; they become incorporat- subjective) understanding of the ed, through the evaluation pro- world (the larger system) around cess, into the agents’ rule models them. They allow the agents to [emphasis added]. (Hoffmann, perceive and define their situa- 2006, p. 98) tion, predict the consequences of action, and act. In most applica- As it can be inferred from this tions of adaptive agents, the rules dense block quote, adaptation is a pro- are behavioral, but they can also cess that shapes the behavior of agents, represent identities, interests, and meta-agents, and systems. Using the goals. (Hoffmann, 2006, p. 98) grammar defined in this section, it can be said that whereas agents are the gen- The second procedure, credit erators of the corpus, adaptation is the assignment, requires the introduction grammatical rule under which the gen- of the concept of fitness in order to be erators combine to make a meaningful understood. Fitness is a concept that in sentence. mathematical genetics is used to repre- To understand how adaptation sent the “ability of an organism to pro- works, it is useful to borrow from com- duce successful offspring” (Holland, puter science and look at how adaptive 1995, p. 65). In complex systems theory agents are programmed in ABM and and computer science, fitness is instead

124 Rethinking the International System as a Complex Adaptive System used to measure “the overall strength” tions is not yet concluded, an agent has of an internal rule of an agent (Hol- to be able to think and simulate the fu- land, 1995, p. 65). The underlying idea ture. As Holland suggests, he can do so is that not all stimulus-response rules by building internal models and discov- are equally effective in achieving agents’ ering new rules. goals or in guaranteeing their surviv- Rule discovery creates new inter- al. To make an example, if we think in nal rules through a process that mimics terms of survival of an agent, an “IF I evolution. This mechanism has well rep- see the cliff, THEN go straight” rule is resented Holland’s genetic algorithms, less fit than one that has an effector that which serve to combine and crossover says, “THEN turn 180 degrees.” rules of behavior to create plausible and In order to understand which fit new rules (Holland, 1995, p. 57). Like rules are fit, an adaptive agent assigns in chromosomal crossover, genetic algo- credit to each rule based on the payoff rithms select couples of high credit rules received after that the rule has been and then cross them over with elements effected. However, if there is no direct of randomness to create an offspring reward after the execution of a rule, an rule. In turn, the child rule is evaluated agent is faced with a dilemma regarding and, if considered strong, crossed over credit assignment. If my rival increas- with another rule. Over time, the out- es defense spending, should I also in- come of this procedure fosters in the crease mine in the eventuality of war? selection of new rules of behavior and If the war never occurs, how do I mea- strategies with high potential. sure the payoff of rearming vis-à-vis not Explaining in detail how to pro- rearming, or rearming just a little? This gram an adaptive agent is out of the is what it is called a credit assignment scope of this paper. The reader will find problem. An agent has to be able to as- in the bibliography useful sources that sign credit to rules that (1) have no di- exhaustively explain how to program an rect payoff, and (2) are part of a chain of ABM with properties of credit assign- action that is not yet concluded. ment and rule discovery. For the scope In the first case, the problem can of this study, what are of interest are the be addressed by using a mechanism underlying rules of the process of adap- that in mathematics is described by tation, which if contextualized to IR can bucket brigade algorithms. This mecha- provide novel insights and new under- nism serves to strengthen the credit of standings. In particular, the concept of rules that belong to a chain of actions adaptation is fruitful to rethink agents’ that ends with a good payoff (Holland, behavior in international politics. 1995, p. 56). For instance, the rule that Regarding behavior, one com- says “preemptively arm” would be re- mon assumption of positivist IR theory warded with a high payoff only if it is is that humans, and therefore states, are part of the chain of actions that has led to some extent rational; if not fully, at to the overall survival of the agent. In least in bounded terms. Rationality is in the second case, since the chain of ac- this sense the higher order rule of struc-

125 Journal on Policy and Complex Systems tural IR theories. For instance, neoreal- Adaptation allows us to go be- ism derives agents’ behavior from the yond behavioral assumptions that flat- system in the assumption that all the ten the heterogeneity of the internation- units of the system would act similarly if al system and assume states to be acting posed is the same situation or under the under unifying and static principles. same system’s constraints. Since the as- Whereas structural theories generalize sumption of rationality implies that the contextual and particular patterns of units of the system share equal internal behavior to all the units of the system, rules, equal environmental inputs result complex systems theory goes one step in equal and static behaviors. As Axel- deeper and generalizes how behavior rod argues, rational choice and struc- emerges among the actors of the sys- tural theories assume that behaviors are tem. The difference between the two ap- a given, and do “not worry about where proaches is fundamental. In neorealism they come from” (Axelrod, 1997, p. 95). and structural liberalism, maximized Conversely, in complex systems power/security and utility are assumed theory, rationality is not a given, but as general behaviors; in complexity the- a construct. Rationality is an abstract ory, they are just some of the emergent concept that agents use to refer to a behaviors that actors can happen to specific set of rules that they see as fit. have. Just as for rationality, those behav- However, this specific set of rules is iors are a consequence of actions and not objective as in structural theories. not a premise to them. They are partially Instead, it is subjective, or (at best) in- incidental, and partially the outcome of a selection of fit rules made by agents. tersubjective among a defined group of agents that are part of the same breed or In addition, by using the concept niche. Adaptive agents do not share the of adaptation, agents and systems can be same set of rules of behavior, nor assign theorized dynamic. Behaviors change fitness to their internal rules equally. over time in a process where evolutionary changes in one agent “induce co- Indeed, depending on coevolution and evolutionary changes” also in the other adaptation, a single rule might have agents (Gros, 2011, p. 206). The system very different levels of fitness among itself gains a role that goes beyond the the population (Harrison, 2006a, p. 9). one usually assigned to it by structural The fitness of rules even changes over IR theories. Not only it acts as a con- time within an agent due to learning straint to the agents, as neorealism says, and coevolution. In sum, it is devious but it becomes a generator for new inter- to talk about rationality, especially in a nal rules of behavior of the agents (Hoff- singular form, because there is no such mann, 2006, p. 98; Waltz, 1979, p. 109). a thing as a rational or irrational behavior. What we commonly define as ra- Corpus: Information Processing tional behavior is a consequence of our and Self-Organization actions and not a premise to them. The premise is adaptation: the higher order Adaptive agents generate self-organi- rule of CASs. zation and entropy-defying behavior at

126 Rethinking the International System as a Complex Adaptive System the system level (Mitchell, 2009, p. 40). agents sampling data in a stochastic and Self-organization, as previously men- decentralized manner (Mitchell, n.d.). tioned, arises from the local interaction Accordingly, social organiza- of agents with limited information and tions make sense of system dynamics computational power and creates stable via agents working together in a “paral- macroscopic patterns at the aggregate lel fashion” and acting with elements of level (Epstein & Axtell, 1996, p. 35). It randomness (within the boundaries of entails that systems themselves com- self-regulation) to sample and explore pute information. information across the whole system Organized behavior occurring with- (Mitchell, 2005, p. 4; Zhong et al., 2005, out centralized control is the outcome p. 137). Randomness, in turn, is always of parallel information processing at adjusted by coevolutionary dynamics the individual and aggregate level. and occurs in a back-and-forth of bot- Agents process information, as previ- tom-up and top-down processes that ously explained, by using internal rules channel agents’ behavior. As Mitchell of behavior. Information for them is writes: something static and specifically locat- As in all adaptive systems, main- ed. It is something that is fed to them taining a correct balance between or that they retrieve something passive these two modes of exploration that they can precisely or statically lo- [bottom-up and top-down] is cate in a particular place of the system essential. Indeed, the optimal (Mitchell, 2009, p. 180): a page on the Internet, a book in a library, a law in balance shifts over time. Early the civil code. Information, however, explorations, based on little or comes in another shape and forms at no information, are largely ran- the aggregate and social level. dom, unfocused, and bottom-up. In biology, information is often re- As information is obtained and ferred as “analog patterns distributed in acted on, exploration gradual- space and time over the system” (Mitch- ly becomes more deterministic, ell, n.d.). Instead of being something, focused, and top-down, in re- static and statistically located, infor- sponse to what has been per- mation takes “the form of statistics and ceived by the system. (Mitchell, dynamics of patterns over the system’s 2005, p. 5) components” (Mitchell, 2009, p. 180). Because data are encoded “as statistical Having discussed what plays the and time-varying patterns of low-lev- role of information and how informa- el components,” no single agent “of the tion is sampled, the final part of this system can perceive or communicate the section addresses what is the meaning ‘big picture’ of the state of the system” of information and why information (Mitchell, 2009, p. 180). In other words, processing leads to self-organization in information cannot be retrieved deliber- the international system. The meaning ately; therefore, the system has to rely on of information is important because

127 Journal on Policy and Complex Systems agents decide their course of actions function of self-organization. Self-orga- upon it. The meaning is always subjec- nization emerges from the coevolution tive and contextual; however, agents of rules of behavior among adaptive use shared criteria to assign meaning agents as an evolutionary response to to information. In biological terms, the the complexity of the system. Via or- meaning of information is tied to fit- ganization, agents are able to process ness and survival. Information means information collectively and increase something to an agent based on how their computational power. In addi- it affects its fitness (Mitchell, 2009, p. tion, self-organization increases deter- 184). Henceforth, the appropriate re- ministic and focused behaviors among sponse to an input is one that increases agents, with the outcome of increas- the overall agent fitness. ing the overall efficiency of the system Fitness and versatility in rules of (Mitchell, 2005, p. 5). In other words, behaviour are what determine the over- self-organization acts as a magnifier for all fitness of an agent (Holland, 1995, coevolution of fit rules among agents. p. 63). Since adaptability is an essential Social organizations, and in par- attribute for agents survival, the success ticular the nation-state, are systems of an agent does not derive from its “raw with strong self-organization and top- power plus cunning,” as social Darwin- down processes that channel agents ists and realists believe, but from its into increasingly deterministic and fo- ability to cope with the complexity of cused behaviors. They have no purpose the system, to process information and outside of those defined by their com- discover new fit rules (Clemens, 2006, ponents. Nevertheless, they do have p. 74). Moreover, agents’ fitness are in- an inherited function, which is one of tertwined in a coevolutionary process the favoring coevolutions and promot- (Clemens, 2006, p. 75). For instance, in ing fit rules among their population. “an arms race, the peaks of a predator For example, nation-states execute this and its prey may gain or decline accord- function by balancing bottom-up and ing to changes in their offensive and top-down processes with institutions, defensive capabilities” (Clemens, 2006, unfocused and focused behavior with p. 75). If the attacker gains a new lethal norms, randomness, and determinism attack tactic, his fitness peak will rise, with redistribution. and the one of the prey will decrease. Conversely, the international However, if the prey develops a counter system has only a “passive” role in fa- tactic, the peak of the attacker will de- voring coevolution. Whereas states act crease. Yet, both will be better off than as meta-agents to promote fit behavior, the rest of agents that have not been part the international system is only a place of the coevolutionary process, which where coevolution takes place: a medi- did not adapt to the new offensive and um for agents to interact and adapt to defensive tactics. each other. System-wide self-organiza- However, the concept of fitness is tion still subsists, but it is less structured possible to understand the evolutionary and less resilient. Partially it is so be-

128 Rethinking the International System as a Complex Adaptive System cause the system is composed of many concepts of fitness, adaptation, coevo- different heterogeneous components, lution, self-organization, and informa- each embedded in a different niche and tion processing. each with its own environmental and The first section looked at the social context. In addition, partially it state of discourse in IR and specified is so because information processing why complex systems theory stands out on a global scale is computationally ex- as a viable research method for dealing pensive. Which means that information with the multi-faced complex reality of sampling has to rely even more on ran- international politics. As it was pointed domness and loosely regulated explor- out, complexity theory could potentially ative behaviors. In this sense, disorder integrate different IR school of thoughts in the international system should not by using an inside–out view that mix- be seen in a negative light.10 Far from es the ontological perspectives of con- being a source of chaos, self-organized structivism and structural theories. anarchy in the international system Moreover, complex systems theory pro- bends disorder to generate entropy-de- vides novel analytical tools that could be fying behaviors.11 used to tackle the nonlinearity of social systems, which instead is persistently ig- Conclusion nored by traditional IR theories. The second section introduced his paper was set to formalize the methodology of complex systems a complex systems theory ap- theory and agent-based modeling. It de- Tproach to the study of inter- fined the properties of a complex adap- national relations. It defined a meth- tive system and described the interna- odology capable of dealing with the tional system as composed of many nonlinearity of international affairs diverse, interconnected, and indepen- and proposed a new taxonomy for the dent agents that iterate nonlinear rela- discipline built around core ideas of tionships from which multilevel behav- complexity theory. The study has gone ior emerges and evolve. As advocated in some way toward enhancing our un- this section, IR scholars should make derstanding of the international system methodological changes in the way they by proposing an alternative perspective study international affairs. Modeling on international affairs that uses the should shift from continuous to dis-

10 As Walter Clemens writes, fitness is found in the middle ranges of the spectrum between ultrast- ability (rigid order) and instability (chaos). With “creative and constructive responses to complex challenges [ ... ] more likely to be found close to the edge of chaos than toward the other end of the spectrum” (Clemens, 2006, p. 74). 11 Self-organized anarchy differs from anarchy as conceptualized in neorealism. Whereas both imply lack of central control, only the former assume nation-states to be functionally differentiated within the system. The role of randomness has largely been misunderstood in positivist IR theory and it is one of the reasons why scholars have often been “slipping” between levels. Due to a wide- spread deterministic-centralized mind-set, there has been a tendency to believe that randomness is disruptive of patterns and that stable organized patters arise under the coordination of a central controller (Waltz, 1979, p. 97).

129 Journal on Policy and Complex Systems crete, from linear to nonlinear, from de- consequence being the establishment of terministic to stochastic, from abstract self-organization among agents. One of to detailed, and from homogeneous to the more significant arguments made composite (Downey, 2012, p. 4). in this study is the one that self-orga- The third section introduced a nization is a property of systems that new taxonomy rooted in the proposi- emerges from coevolution of adaptive tions of complex systems theory and agents as an evolutionary response that then used it to reframe the internation- serves to supply for agents’ limited real system. Then it analyzed the granu- sources and foresight. larity of the international system and From this perspective, it was differentiated between agents (people) then possible to explain that states are and meta-agents (social organizations), complex systems with strong levels of explaining that the latter should be self-organization and top-down pro- studied as structures that have emerged cesses that increasingly channel agents from the adaptive interactions of the into deterministic and focused behav- former. After having exposed the mul- ior. Hence, the function of states was tilevel nature of adaptive systems, the suggested to be the one of the favoring section criticized the traditional com- coevolutions and promoting fit rules partmentalization of world politics into among their population. Conversely, it levels of analysis, which prevents schol- was noticed that the international sys- ars to see the relationship between mi- tem remains only mildly self-organized. crospecifications and macrobehavior. With a possible explanation for this In the section on the “operators” characteristic being that disorganized of the international system, it was in- behavior is, to an extent, necessary for ferred that adaptation is the higher or- the system to process global informa- der rule that drives agents’ behavior. It tion, which takes the form of distribut- was suggested that, instead of assuming ed patterns over the system. a unitary (and maybe rational) behavior for all agents, it would be better to assume how behavior is constructed. Bibliography The section then described how adaptive behavior comes about through the Axelrod, R. (1997). The complexity of processes of performance system, credit cooperation: Agent-based models of assignment, and rule discovery. competition and collaboration. Prince- Lastly, the final section looked at ton, NJ: Princeton University Press. the outcomes of adaptive interactions among agents and evaluated what is the Axelrod, R. (2006). Alternative uses function of states and the internation- of simulation. In N. E. Harrison (Ed.), al system. The research indicated that, Complexity in world politics: Concepts in the international system, not only and methods of a new paradigm (pp. agents process information, but also 137–142). New York: State University the system is actively doing so, with the of New York Press.

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