The best books on The Psychology of War

Aristotle argues that man is, by nature, a ‘political animal.’ You are a forerunner in the field of political psychology and the co-author of a volume entitled Man is by Nature a Political Animal. Please tell us what Aristotle and you mean.

I can’t speak for Aristotle, but we use that title because the book examines how evolutionary biology and behavioral genetics intersect and explain complex social and political behaviors, especially the nature of political ideology. We adopted that title because there had been a longstanding debate about whether various aspects of political thought and other parts of social behavior result from nature or nurture. For most of social science history, at least the last fifty years, it’s been assumed that the political behavior comes from processes of socialization—from school, from family, from friends. The work that we’ve been doing—looking at heritable aspects—has shown that a nontrivial part of what makes up political ideology really comes from genetic components. So we adopted that title to say: it’s not just nurture it’s also nature. We wanted to reincorporate the notion that nature contributes to political ideology in humans.

Political Psychology in International Relations is the title of the pioneering book you wrote on this topic and the subject of our conversation today. Please make your case for the importance of psychology in understanding international relations in particular.

The tradition in most of international relations is to think about institutions; most of the analyses take place at the level of the state. Psychology contributes to international relations by incorporating the importance of individual actors, thoughts and behaviors and analyzing how they affect large-scale outcomes. Consider the importance of psychology in understanding international relations in terms of specific state leaders—an iconic case is Hitler. Increasingly there are lots of non-state actors making huge impacts; Bin Laden worked a tectonic shift on international relations through terrorist actions.

“We wanted to reincorporate the notion that nature contributes to political ideology in humans.”

So, one of the ways that psychology can contribute to our understanding of international relations is by investigating the impact of the individual. There tend to be two kinds of ways those analyses take place. One is by looking at leaders and elite decision-making; that’s the tradition I come out of. There is also another tradition of looking at mass political behavior, at voters, that’s not where I’ve done the majority of my work.

How do you use the methodologies of psychology in your work?

The main methodology that we draw from psychology is laboratory experimentation and the use of controlled manipulation to examine the effect of a specific variable on political outcomes. There is also a lot of field experimentation.

If you are analyzing mass political behavior, you might use polling data. The original idea for survey research came out of psychology at Columbia University in the 1920s and 1930s, and subsequently was refined by political scientists. So surveying is a major methodology used by those looking at mass political behavior.

Other methods used in political psychology come from other disciplines. For example, using historical or archival records to examine how a leader might make a decision involves qualitative analysis.

Turning to your book selections, I’d like to begin with How Statesmen Think.

All of the books I’ve chosen are by amazing authors. There are specific books that I recommend, but in most of the cases if you pick up any other book that these authors wrote you’d find wonderful examples of their thinking as well.

This book is Bob Jervis’s most recent volume. He is a political scientist at Columbia University and was my dissertation advisor. Bob put political psychology on the map. His most famous book is Perception and Misperception in International Relations, where he makes the case for the importance of psychological variables in international relations. This book is a compilation and expansion of articles looking at the importance of individual leaders and decision-makers on large-scale outcomes in international relations. It’s a wonderful demonstration of how he thinks through the subtle and nuanced ways that individual decision-making affect large-scale social and political outcomes.

The American president’s Twitter attacks on intelligence agencies make Jervis’s essay on “Why Intelligence and Policymakers Clash” so salient. To give us a flavor of his work, can you please tell me about his insights on this topic.

The Central Intelligence Agency brought Jervis in to do a post-mortem on the Iranian hostage crisis in 1979. He continued to work with the intelligence community and became one of the senior people involved in the Historical Review Panel, which looks at how analogies influence decision-making. Bob examines how decision-makers are affected by biases.

Teeing off the debate about the extent to which former Vice President Cheney attempted to influence the intelligence process in making the case for war in Iraq, he looks at the broader problem of whether you can convey intelligence without bias. If information conforms with your preexisting understanding, you do not subject it to the same level of scrutiny that you apply to information that does not conform with your biases. These are natural and normal human biases which affect how we assess the veracity of any information that comes across our table, including intelligence information.

Bob examines both the politicization of the intelligence, which is very relevant right now, and the underlying psychological biases that can and do affect not just intelligence analysts but all of us when we examine new information, regardless of whether or not we are being subject to external pressure to come to a particular conclusion.

Let’s turn to Demonic Males by Dale Petersen and Richard Wrangham. Please tell us about the book and its application to international relations.

Richard Wrangham is in evolutionary biology at Harvard and this is an evolutionary analysis, a very compelling one, of the origins of human violence and its analogue to aggression in chimpanzees.

Demonic Males is instructive, especially in informing us about the sexual expression of aggression and how sex differences emerge in the use of physical aggression. Why is it that physical aggression occurs in higher degrees among males? Wrangham uses his erudition and impressive evidence to describe the origins of this difference and why it’s meaningful.

This work is important because it tells us a lot about the sources of conflict among humans. Political psychologists look at human behavior in the context of large complex conflicts, including war. How those conflicts emerge and are influenced by biology point the way to how we can avoid and end conflict.

You argue that political theory should be grounded in evolutionary biology. Please outline the biological bases of political behavior and tell us about how biological research is informing analysis of political behavior.

Human biology influences all of us through emotions. How do emotions get activated and affect social situations? How does fear affect our attitudes towards immigration? How does disgust influence our attitude toward transgender bathrooms? How does anger affect our propensity for war? These important aspects of human nature play out in political ways because we’re political animals. We develop rules and institutions that are designed to allow us to live in a society together.

A big part of politics is trying to get people to behave the way you want them to behave. There are some basic concepts, not a lot, that you can see play out across human history in different ways. The particular manifestation of them may change with time and culture but the underlying dynamic comes from the longstanding ability of our ancestors to thrive, survive and mate to produce another generation. Those concepts include resource allocation—how do you decide who gets the food or the territory or whatever. And issues related to sex—who gets control of reproduction. And in-group preservation—how do you protect your group from predation and how do you keep out others. This is where immigration comes in, and issues related to war.

“This work is important because it tells us a lot about the sources of conflict among humans.”

These underlying political, psychological and social goals manifest in different ways. The modern instantiation can look very different when you consider a topic like sex. A hundred years ago there were rife fights about prostitution. Today the fight is about transgender bathrooms. Yet the underlying issue remains—who gets to decide what is appropriate sexual behavior. So although the instantiation of struggles changes across time and culture, the underlying impetus remains the same.

We’ve demonstrated that these impetuses have a heritable component. You can find some source of these impetuses in human genetic factors. That is why these impetuses arise throughout human history, no matter where you are, no matter when you are.

Next on your list is a book about the ancestral roots of behavior, Tribe by journalist Sebastian Junger. Please tell us about the book and what the book tells us about the psychology of war.

Junger, an author and a journalist, wrote two related books, one is called Tribe and the other is called War. These are about the experiences he had while embedded with American troops in Afghanistan. They are descriptive.

What I really like about Tribe is that he talks about the importance of community. We, as a modern society, have really lost that sense of ‘tribe.’ We evolved for hundreds of thousands of years in tribes on the African savannah. Now society is so atomized. We think we’re connecting through social media on our phones and computers but we’re actually becoming more disconnected than ever. A record level of adults are alone and a much higher percentage are single than at any other time recorded.

“A big part of politics is trying to get people to behave the way you want them to behave.”

As horrific as combat is, the experience of serving in the military creates a sense of community that many miss when they return to civilian life. This is a brilliant insight into the nature of coalitional psychology. When in a dangerous environment, things that ordinarily divide a society, whether race or politics, tend to dissolve because everyone needs to have each other’s back to survive. When people come home what they really miss is that sense of unity and community. Junger suggests that what those returning from war experience is a feeling of isolation that we must work to overcome.

Society is suffering from not just political polarization but also social polarization. That lesson is really important. It’s a really short and brilliant examination of that issue.

How are Junger’s insights related to the psychology of international relations?

It’s directly related, in that it examines the psychological impact of combat experience. And Tribe provides other insights through its examination of in-group and out-group behavior. It’s a metanarrative for the kinds of conflicts that happen between states.

Let’s get to Sex and World Peace. Please tell us about this volume, by Valerie M. Hudson and co-authors.

Valerie Hudson, a political scientist, and her colleagues have looked at the critical relationship between sexual equality and international conflict.

Her earlier book, Bare Branches, looks at sex ratio imbalance—how when you have too many men and not enough women it can lead to increasing conflict, authoritarianism, and mercenary action. If men lack reproductive access they are anxious to raise themselves in status and get enough money for marriage so that they can create their own families.

“Gender imbalances…have huge implications for peace, development and stability in society.”

Related work that she’s done looks at patrilocality and how, when women are sold away or forced to move from their family members, they become particularly vulnerable to abuse. People might think about violence against women as a domestic issue. What Hudson shows is that where there is gender inequality, where there are too many men and not enough women, there are large-scale social consequences. States become unstable.

In Sex and World Peace they look at many of these kinds of phenomena. For example, in countries where women are not treated as well you get higher rates of aggression—more first strikes in war, higher rates of escalation and more money spent on weapon production. Gender imbalances form an impetus for going to war externally so that men do not become so restless at home that they turn against and topple their leaders. So gender imbalances, Hudson shows, have huge implications for peace, development and stability in society.

Does Sex and World Peace suggest how international relations could become more peaceable and cooperative?

The normative implications of this book include changing laws and practices to increase sexual equality—changing marriage, divorce and custody laws; inheritance laws and property rights.

A lot of aspects of family law affect society, and therefore international relations. For example, most arable land in the world is owned by men but worked by women. When women work their own land, the land is much more productive. So food insecurity challenges could be overcome if we could change laws so that women could actually own the land that they farm. The demographic transition, whereby women have fewer children, is a critical part of any economic development plan. Draconian policies in this regard are obviously part of the story of how China has come so far economically. So helping with family planning is one normative implication. Allowing women to borrow even small amounts of money is another normative implication. We learned from the experience of the Grameen bank in India that women are much much much more likely to repay microloans, because when you give men loans they tend to buy cigarettes and rounds at the local pub while women tend to invest in their businesses. And when women get loans they are likely to have fewer children and they are more likely to educate the children they have, particularly if those children are girls.

There are a host of downstream implications and applications to Hudson’s work. When you reduce aspects of patriarchy you get way better outcomes from society in general. This book is a very powerful reminder that women must be more equal if you want to engender peace and prosperity for everybody.

Finally, a bestseller by Nobel economics prize winner Daniel Kahneman. Please tell us about Thinking Fast and Slow and its pertinence to our topic.

This book reflects back on the work that Kahneman did with Amos Tversky, which won him the Nobel Prize for economics in 2004. (Truth in advertising: Tversky was another of my dissertation advisors). Their work revolutionized the economic understanding of decision-making—the idea that people were rational actors who weighed costs and benefits and made decision for themselves that maximized utility. It turns out that’s not true in most cases. They overturned the foundation of the psychological understanding about how people make decisions.

Kahneman talks about two modes: fast—almost effortless, decision-making, largely based on intuition and emotions—and slow ways of thinking, which are laborious and deliberative. The latter type of decision-making is rarer.

“Political psychology can also be used to understand anomalous actors, such as the current president of the United States.”

Both fast and slow thinking are susceptible to systematic biases. They document these biases. For example, that conclusions can be made based on analogies between past events and current events. Biases themselves are predictable, they lead people to make decisions differently than classical economic analysis predicts. So this book helps people to understand the flaws of their own decision-making, which lead them into situations that they regret. You can see that same sort of decision-making all the time in politics and relations between states.

Kahneman suggests techniques to counterbalance cognitive biases and other cognitive failures. Can what Kahneman teaches be applied toward diplomacy and statesmanship?

Understanding systematic biases, particularly the way historical analogies get used and abused, but also how diplomats are susceptible to these biases, may reduce the negative consequences from them. That’s what I teach.

And finally, how are the findings of your field put to practical use in managing international affairs?

Political psychology can be put to all sorts of use, not just to understand bargaining and negotiation, cooperation and conflict on the international stage. Political psychology can also be used to understand anomalous actors, such as the current president of the United States.