On D-Day, 6 June 1944, 150,000 soldiers landed on the beaches of Normandy to begin the slow march on Germany. It was a turning point, a day on which uncertainty evaporated and the Allies could focus on the struggle ahead. In a war that would claim over 60 million lives and engulf the entire globe, to this day we remain struck both by the depths of depravity and the remarkable feats of heroism that can be achieved by human beings.

Today is another D-Day—Darwin Day. Evolution might seem so divorced from the realm of politics that they have little to exchange. World wars involving millions of people, nation states, complex organizations, nuclear weapons, and the clashing of cultural ideas might seem to mark a line of division in the development of human beings, beyond which evolution has nothing to say.

However, as editors of the politics page, we believe that Darwin’s legacy sheds vital new light on our understanding of political events. For one thing, despite monumental efforts over the centuries, we have failed to prevent wars from occurring—and not for lack of people studying it. Especially following the end of the Cold War and the rise of new forms of conflict around the globe, new approaches are sorely needed. Another reason is that evolutionary science has advanced rapidly in recent years and decades, and important new theories, tools, and methodologies are emerging. Much of the resistance to biological explanations of behavior is a re-run of the sociobiology debates that raged in the 1970s. The science has simply moved on, and we must too. If we are to understand human behavior, evolutionary theory offers the single most powerful and parsimonious framework for doing so.

The levels of analysis and human behavior

This claim is not as controversial among psychologists or biologists as it is among social scientists in general and political scientists in particular. One common fear is fueled by the memory of Nazi attempts to apply evolutionary ideas to politics in ways that are fundamentally dangerous. Fortunately, the ideas and goals of eugenics have been widely and rightly discredited, and have absolutely nothing to do with the modern application of evolutionary theory to human affairs.

Another reaction to the incorporation of evolutionary theory in the social sciences, and especially in international relations, is that there is no need for evolutionary theory, even if they acknowledge that the misapplications of the past are less likely today. For these scholars, the world we are trying to understand is much more than, or even entirely divorced from, the human beings that live within it. The father of modern international relations theory, Kenneth Waltz, famously examined three possible “levels of analysis” in international politics: (1) the international system as a whole; (2) nation-states; and (3) individual human beings. Each of these levels in principle might offer explanations of political events. But Waltz’s claim to fame was to reject not only a role for individuals in international politics, but even a role for states—despite their widely differing characters, cultures and regimes. For Waltz, since there is no monopoly of force “above” states to enforce agreements and regulate behavior, the recurrence of war in the international realm could be explained entirely by the pressures exerted on them by other survival-minded states. Like billiard balls, the actions of one state could be predicted by the actions of others, since all were primarily seeking to maintain their security by the only reliable means: power.

Waltz’s theory remains a powerful perspective on world politics, and theory and practice in international politics often operate with this “neorealist” view as a background against which other factors must be measured. But it is probably fair to say that most political scientists today reject any neat division and accept that all three levels of analysis are, in reality, important influences on politics. World War II is an important illustration of this, because it strongly suggests that even the most significant world events can be influenced by individual human beings and by the character of the nation-states that they create.

Some versions of international relations theory imply that Hitler himself did not make any real difference and, given the constraints upon it at the time, any German state would have behaved similarly in the 1930s. But few political scientists or historians accept such a view. World War II was to a large extent about Adolf Hitler the man (as well as Stalin, Mussolini, Tojo, Roosevelt and Churchill, among others). Influences at the nation-state level are clear as well. The war itself, as well as the Cold War to follow, was not just a conflict over material resources. It was also a conflict between contrasting political ideologies, not least fascism, communism and democracy. The ways in which ideas spread and clashed within and between nations was also fundamental to the origin and nature of the war. And lest we forget the most basic manifestation and consequence of war, the 60 million dead were human beings too. If we are to understand war, then we need to understand the psychology and behavior of the individuals who endure them as well as the psychology and behavior of the leaders and states that decide to fight them.

War and Cooperation

At each level of analysis, evolution has much to offer. For millions of years, humans have evolved in small, relatively nomadic bands, and the challenges of navigating a complex world of family, friends and adversaries, seem to have left a lasting impact on our evolved psychology. Indeed, the most enduring debates in the social and biological sciences are debates on the evolution of cooperation and the evolution of warfare, and we can see the psychological footprint of these evolutionary legacies at all levels of human relationships, from the individual to the international. Often this investigation leads to entirely novel or counter-intuitive hypotheses, with unique predictions that can account for phenomena where other, non-biological theories fail.

For example, mounting evidence shows that individual phenotypic traits such as bicep muscle mass and upper body strength predict a surprising array of variables, from opinions on wealth distribution to beliefs on the utility of force in foreign policy. This appears to be a reflection of how individuals derived different payoffs from alternative social strategies in human evolutionary history, depending on their characteristics. Our brains “know” our physical capabilities, and adjust our preferences and strategies accordingly. Researchers also continue to accumulate evidence of sex differences in war, revealing a disturbing tendency for males to be both the perpetrators and recipients of violence, and to overestimate their chances of victory in war. These trends are predicted by evolutionary theory based on ancestrally recurrent parental investment strategies that differed between the sexes, and over successive generations led to sexual dimorphism in the design of psychological systems that help regulate behavior. Lastly, and more generally, a surprisingly common leitmotif seems persistent across motivations for violence the world over, especially regarding the revenge motive, honor and status, as well our incessant territoriality, which seems only more urgent in a world of evolutionarily novel and territorially-fixed nation states.

There remains much healthy debate regarding the evolution of warfare and cooperation, as well as corollary debates over the implications for “human nature.” However, we should not be led astray to falsely conclude that the existence of adaptations for war suggests that war itself inevitable or necessary. Three reasons suggest it is not.

First and most importantly, if such adaptations do exist, they are designed to operate flexibly in response to dynamic environmental conditions; viz. aggression is not merely the product of a primal urge that springs forth regardless of person or place. Natural selection always prefers strategies that are contingent on context, maximizing payoffs by triggering a given behavior in favorable contexts and suppressing it in others. We can therefore lay the “killer ape” hypothesis to rest.

Second, there is substantial evidence to suggest that many forms of violence are indeed in decline and have been for some time, again forcing us to recognize the conditionality of behavior and the presence of competing abilities and desires, as well as the success of institutions and governments in preventing aggression and promoting collaboration. This leads to the third reason.

An equally large and accumulating body of research reveals the deep and broad human capacity for cooperation and peacemaking. In a surprising twist, it may in fact even be the case that the social pressures unleashed by an especially violent past are in part responsible for our remarkable ability to cooperate. It is notable that one enduring measure of battlefield success is in-group solidarity, coordination and cooperation. Human conflict may have demanded, or boosted, the evolution of cooperation. Although we are agnostic on the question of whether this renders war a “creative” force, it would be folly to fail to recognize the common and sometimes tragic link between inter-group conflict and within-group cooperation. Here again, however, even this tragic link can be amended as humans have continually sought over time to expand their social and political associations ever outward. As the world globalizes, significant evolutionary questions arise over whether and how our evolved, small-group adaptations will hurt or help us.

States, Parties, and Leadership

Clearly, much evidence seems to indicate the existence in humans of a complex coalitional psychology that is at the heart of many political behaviors. We see this debate at the international level in explanations for the stubborn prevalence of war and the puzzle of cooperation. States distrust other states, but are able to ally against common enemies. At the domestic state level, however, one debate that has gained momentum is the “red brain/blue brain” discussion. As John Hibbing and his colleagues have noted, certain “bedrock principles” have led to enduring questions that political coalitions have had to solve the world over and throughout time. These are questions such as: how to treat out-groups, how to deal with in-group rule breakers, such as free-riders (e.g. punish or rehabilitate?), the proper conduct of leadership, and more generally, the appropriateness of absolutism or compromise on political issues. Hibbing and colleagues argue that these core puzzles have been sufficiently enduring in human social life that our answers to these questions underlie the liberal-conservative spectrum, and even have a genetically heritable component. Others such as Jonathan Haidt have taken a (not-mutually exclusive) neuroscientific approach and have investigated the underlying brain systems active in liberals and conservatives, with some surprising and provocative results. See TVOL’s interview with Haidt here.

In addition to the conduct of political parties in response to the seemingly ubiquitous questions of how to achieve in-group solidarity and successful foreign relations, researchers have actively investigated the biological dimensions of leadership. Even in egalitarian societies that enforce strict rules regarding ‘upstarts’ who may seek to gain undue influence over others, political groups have had to deal with the challenge of political power that becomes centralized around formidable or influential individuals. Two intertwined challenges here are the challenge of group coordination when exigencies demand a quick response, and the challenge of resisting exploitation by individuals of great influence.

Importantly, although modern nation-states are more accustomed to long-term stable leadership, it is more likely that leadership in ancestral social groups was flexible, fleeting, and varied based on the current challenges facing the group. For example, researchers have shown that subtle cues in the face, in interaction with whether the group is currently at war or at peace, predicts one’s preference in voting among leaders. Furthermore, although the demands of a given task will do much to condition the emergence of leadership, there is new evidence that associates a specific DNA sequence with leadership skills in the form of supervisory or managerial skills.

The seemingly ubiquitous challenges of internal political organization and the risks and benefits of strong leadership are all too familiar and central to human associations. Research continues apace in all these areas, but perhaps most encouraging is one trend that permeates the rest: A greater consciousness of, and explicit movement towards, consilience.

Evolution and consilience: The way forward

At the end of the day, social and life scientists studying humans are all students of behavior, and evolutionary theory continues to gain ground as a useful, and in many cases indispensible tool for exploring the depth and complexity of the human experience. This is reflected in frequent and rigorous publications in many of the leading scientific journals, as well as the fact that these publications are multi-scholar, cross-disciplinary collaborations between biologists, psychologists, economists, anthropologists, political scientists and many others. It is also reflected in extensive coverage by major news outlets such as The New York Times, The Economist, and of course popular television shows such as the Colbert Report and Daily Show.

However, if this movement is to consolidate the gains it has made in the direction of consilience, greater effort must be made, especially in the social sciences, to break down antiquated notions that persistently make it difficult for scholars—especially young scholars breaking the norms of the trade—to engage in innovative cross-disciplinary research. For example, caricatures of evolutionary theory appear indefatigable in many instances, such as the belief that evolutionary explanations imply or require rigid (“hard-wired”) behavior, or that evolution can be used to justify the belief that humans are “fundamentally” selfish and competitive, or the reverse, that they are fundamentally altruistic and cooperative.

Social scientists, like the objects they study, are human, and it takes a long time for beliefs to shift and fears to settle. Thus, many scholars will continue to be wary over the potential reappearance of Social Darwinism, and it will take time for the academic community as a whole to shed popular but flawed impressions of evolution and replace them with a modern, rigorous one, replete with its necessary complexity and nuance.

Lastly, therefore, if consilience is to be successful it must couple academic collaboration with good old-fashioned public diplomacy. Evolution: This View of Life has prioritized public diplomacy as a central aim, and in collaboration with the Evolution Institute and the Social Evolution Forum, it has been instrumental in sparking active and constructive discussion at the intersection of academia and the public eye. TVOL is uniquely focused on both breadth of coverage and depth of analysis, and it currently remains the only web magazine of its kind. As editors of the politics section, we aim to provide a forum for all new research on politics, irrespective of topic or level of analysis, but unified by a common focus on applying the insights of evolution to the many puzzles of political behavior.

No one is under any illusions about the ability of evolutionary theory—nor indeed any other theory—to end war, create peace, halt climate change, or solve any other of the great challenges that confront us in the 21st century. But given the urgency and magnitude of such tasks, what we should not do is leave any stone unturned. For over a hundred and fifty years since Darwin introduced his theory of evolution, many stones have been left unturned. Darwin Day is a rallying call to pick those stones up and look. We do not know what we may find.