I am often asked to review books for journals, but I usually decline because I am either too busy or do not find the work compelling. When the AJIL editors asked me to review International Legal Theory and the Cognitive Turn, edited by Anne van Aaken and Moshe Hirsch, I immediately agreed. I suspected this collection of thirteen essays would make a significant impact, and I was right. The book focuses on how cognitive studies and international legal theory converge to show how people’s minds shape their understanding of reality and their judgments about the law. It brings the human side of international law decisionmakers and participants, with all their biases, into the scholarly conversation alongside traditional state-centered theories. People matter, and we are not all the same.
It is not easy to review an edited collection like this one, as there are far too many essays and authors for me to name them all. Instead, I would like to share my thoughts on a few of the themes that emerge, essay by essay, into an innovative whole.
Human Cognition
The central characteristic of the cognitive turn has been the reliance on empirical research regarding preferences, beliefs, and decision making to amend classic rational choice- and game-theoretic models. At least, that is how we talk about it in my fields of political science and behavioral economics. It is by no means a new idea, as the book clearly acknowledges, that human decision making is not perfectly rational. It is also not news that people tend to follow certain thought patterns that are relevant to how they think and act. We know from decades of research that people have systematic biases, are boundedly rational, experience emotions, and tend toward certain types of thinking, like loss aversion, that affect how they process and react to information and their environments. And the study of international law can and should build upon this knowledge—one of the great contributions of this book, which calls out to scholars to be more reflective on how human biases shape our understandings of the law and how international legal actors reach and implement decisions.
The cognitive turn foregrounds several questions about how legal decisions are made. It suggests that existing, broad-based theories of international law are in some ways inadequate and therefore potentially misleading. Yet at this stage in their development, cognitive approaches have not yet developed to the point of correcting or displacing these other theories. While this strand of research is very promising, its implications for broader theorizing are not yet apparent, and the volume can be read as an invitation to undertake additional research in this area.
Yet until recently, most of the evidence about human cognition has come from studies on students and other readily available subjects for research.Footnote 1 That’s helped scholars understand some kinds of behavior, such as voting.Footnote 2 International law may touch all of us in various ways, but most of the profession is not run by the students or voters we tend to study in cognitive science. It often involves highly educated elites, be they lawyers, judges, arbitrators, politicians, and the like, who may operate in a cognitively different way than most students and voters. If we are going to talk about how the cognitive turn provides insights into international legal theory and process, we need to talk not just about what we have learned from decades of research on mainly students, but also about elites.Footnote 3
Here are just some of what the scientific community thinks we know about how experienced elites might exhibit cognitive processes that are different from the populations we normally study. They tend to be more cooperative but also overconfident; they manage risk in a different way than less experienced people; they are better at using heuristics like mental shortcuts or rules of thumb when confronting complex decisions; and they tend to be more strategic in their interactions.Footnote 4
Of course, not all “members” of the international law community are highly or equally experienced, a fact that many of the international legal theories considered in this volume tend to gloss over. But these insights do suggest that when we think about what the cognitive turn means for international legal theory, we need to think about how cognition depends not just on the nature of being human, but also on how elite experience shapes the nature of cognition. Differentiating levels of experience could inform the many flavors of legal theory illuminated in this collection of essays. For instance, what this means for feminist approaches to international law (Fikfak, pp. 109–30) may have entirely different implications than for constructivist (Johnstone and Sukumar, pp. 60–86), cognitive-sociological (Hirsch, pp. 197–219), or Marxist (Bagchi, pp. 265–88) approaches.
Take what scholars in multiple fields call “constructivism” as an example (see Johnstone and Sukumar, pp. 60–86). Consistent with the cognitive turn, this view of the world questions the idea that people are perfectly rational when they do things like form preferences, but it also tends to emphasize the social nature of these preferences and calls attention to a central role for socialization.Footnote 5 The cognitive turn may have both individual and social components, as the essays in this volume suggest, but there remains a tension in the field between what historically has been the individualist focus of the cognitive turn and methods of research and theories that rely more heavily on social structures. That said, both behavioralists and constructivists give credence to prevailing norms and heuristics as key elements affecting individual and social processes, so there is much to be gained in the marriage of the two.
Tradeoffs and Variety
One of the many strengths of this collection is its deeply interdisciplinary nature. Among the many authors are comparative public law experts, international legal scholars, economists, psychologists, philosophers, political scientists, sociologists, as well as a fair share of practitioners. That feature leads to an inclusive view of how insights on cognition can inform international legal theory. Another strength is its wide-ranging selection of legal theories. This includes positivism (Peat, pp. 21–42), legal realism (Cohen and Bodansky, pp. 43–59), critical approaches (Krebs, pp. 87–108), liberal normative theories (Howse, pp. 131–53), transnational legal process and the associated New Haven School of thought (Jefferies, pp. 154–76), and even critical legal geography (Stolk, pp. 240–64), among others mentioned earlier.
Yet as is true in so many domains, a blessing usually comes with a tradeoff. The blessing is the breadth of knowledge, expertise, and perspective. Each essay brings something important, different, and unique to the table. With that comes the tradeoff: it is hard to know exactly what to take away as an overarching, digestible, or concrete idea or theory. I see this volume as vastly more than the sum of its parts, and yet the real punchline is so broad—that cognition affects how legal actors think about international law—that readers will be left to exploring each essay individually to find their meaning. That is not a criticism, but a tradeoff that comes with such a rich scope of knowledge across so many distinct theories and intellectual domains that invites more broad-based, ground-up theorizing. If you want an easy scholarly answer for how legal decisionmakers think and behave, this book will not provide one. If you want depth and diversity in ideas, approaches, and experience, this book is your ticket.
Add to this another strength: a wide-ranging variety of cognitive approaches. Indeed, there is really no such thing as “a” single cognitive turn but rather many different theories and approaches to thinking about cognition, not all of which operate at the same level of analysis or with the same potential implications. Some visions of this “turn” are a fundamental challenge to rationalist theories of behavior. Systematic biases can lead to ways of thinking and acting that are contrary to rational thinking. Emotions can get in the way, and so can framing, among many of the other attributes raised throughout this collection, which are often interpreted as a direct and deep contradiction to rational models of decision making.
But not all behavioralists think that way. For others, this cognitive turn is not seen as a contradiction to existing rationalist ways of thinking, but instead complementary, and many believe that some of the key assumptions of the “turn”—and concepts that revolve around things like preference formation and risk aversion—can be readily incorporated into at least some existing choice- and game-theoretic models.Footnote 6 Here too, the curse and blessing are the same: an extremely diverse understanding of what the cognitive turn means creates room for exploration, but also presents the challenge of so much variety that the tradeoff is less depth into any one model, approach, or way of thinking. Which flavor of cognition you favor has direct implications for how the “turn” can inform international legal thinking.
As the volume nicely demonstrates and explores, there is a history to the turn, which converged early on around the idea that people are biased in systematic and prevalent ways. For example, Prospect Theory produced the idea that people are much more prone to disliking what they perceive as losses than they are to appreciate essentially equivalent gains, and that we tend to overweigh certain types of outcomes and also small probabilities.Footnote 7 But the more recent trends now point to heterogeneity across individuals, meaning that we do not all tend to act out or process these kinds of biases in the same way, much to my earlier point about how elites might think and process information differently. Surely, the study of international legal decision making can benefit from such an acknowledgement, but here, too, the insights that can be derived from the cognitive turn for various theories of international law will depend a lot on whether we are looking for systematic biases inherent in being human or for differences in cognition across certain types or groups of people. The volume does not explore this question, but there is much to be learned from both approaches.
Aggregation
All of us who study big outcomes—things like the causes of war, the utility of law, how courts perform, how states do or do not accept or implement international legal obligations—face a similar challenge from the cognitive turn: what can learning about how cognition affects individual decisionmakers’ preferences, actions, and choices tell us about how institutions are created, designed, or behave? In other words, how do we get from what is in one person’s mind to collective outcomes that involve many people and often many institutions, rules, and histories? It is hard to move from what one judge might think or say to how a legal regime looks, feels, or operates. Again, that is not a criticism of this volume; all of us who work in the field face this question. And the volume contains some ideas about how to address this question. But moving from insights regarding individual behavior to insights regarding state actions or the behavior of global institutions is not an easy task, and sadly, there are no “off the shelf” answers. This volume’s struggle on this front is shared by us all.
Conclusion
This collection of essays is a tour de force, and one that I would highly recommend to anyone interested in the cognitive turn or international legal theory, whatever your flavor. Practically, what it could mean for practitioners, I do not know. But for the large and broad field of international legal theory, there is clearly much to be gained on many dimensions. There is great value in marrying these fields, even if that union is broad and expansive and not yet fully defined. This book opens many avenues for new and creative thinking and for future studies. Its challenges are not unique to this collection, but its strengths outweigh those challenges and should have an impactful impression on the field and on this Journal’s diverse readership.
