Balancing Oxytocin and Testosterone – the Key to Ending War

October 22, 2012

                                     By Judith Hand


Humans want “to know.” Curiosity starts with us at a young age, when as children we start pestering our parents asking, “Why?” “Why?” “Why?” As adults, we especially want to know why other adults do what they do and feel the way they feel?

For my project, A Future Without War.org, I want to know why we make war and how, or if, we could end it.

Neuroeconomist Paul Zak’s delightful new book The Moral Molecule answers many of our most vexing, intriguing, and important questions.

The Moral Molecule – Dr. Paul Zak

How do we, for example, account for:

• The powerful attachment of mothers (and fathers) to their children.
• The warm emotional glow we feel from a big hug of genuine friendship.
• Some husbands being more faithful than others.
• Women, in general, being more generous than men.
• Men being much bigger risk takers about everything, from finance to sports.
• Women, in general, having higher scores on tests of empathy.
• The feeling of joy or pleasure we have when we arrive “back home.”
• Our willingness to help strangers in need.
• Our propensity to repay the trust people have in us by extending trust to them in return.
• The fact that, in some form, the Golden Rule—do not do unto others what you would not have them do unto you—exists in virtually all cultures.
The Moral Molecule also has fascinating relevance to war.

Human Nervous System

Decades of research, behavioral and neurobiological, has exploded our understanding of how nervous systems and brains produce behavior, from the jellyfish to the octopus, from dogs to humans. We now have a good grasp on the neuroarchitecture of brains, including our own. We continue to advance our understanding of emotions and how they interact to produce behavior.

Human Brain

We’re to the point of actually looking into the brain chemistry of behavior, the molecular basis of what motivates us. Paul Zak’s work, engagingly presented in The Moral Molecule, is cutting edge, and he has discovered that a remarkable chemical—the hormone oxytocin—profoundly shapes human behavior.


It does so by reinforcing actions that in our evolutionary past provided survival and reproductive advantages.

Yes, a molecule accounts for all of the phenomena listed above and many many more such phenomena as well.

Oxytocin’s first appearance in the study of behavior was in association with reproduction. When a woman is in labor she releases a large amount of oxytocin, which facilitates birth.

It is released upon stimulation of nipples, which facilitates the release of milk during breastfeeding. It importantly accounts for a mother’s pleasure in nursing her babe. All of these results of oxytocin release clearly facilitate successful reproduction.

But Zak’s research is revealing how this nifty, multi-purpose chemical reinforcer also facilitates other physical and behavioral responses, such as pair bonding and empathy. It turns out that this built-in drug of pleasure has been a prime tool of natural selection in steering us into actions that enable us to lead successful lives as extremely social beings.

Drawing Blood

To figure out just how oxytocin performs its magic, Zak has spent a number of years blood-extracting. He opens the story of his pursuit of oxytocin’s secrets by recounting his participation in a wedding at an English country manor.

The bride was aware of his research on oxytocin as being a mediator of moral behavior because she was a writer for the magazine “New Scientist.” She invited Zak to take samples of her oxytocin blood levels before her wedding and immediately after, to see if the emotional uplift of the wedding would alter her oxytocin level.

A Wedding Party

In fact, she wanted him to take samples from the groom and all the other guests who were willing as well. The logistics of blood-drawing and analysis at the wedding and in many other of his research venues makes fascinating and often amusing reading.

The results at the wedding were pretty much as expected: the bride’s levels shot up 28 percent and for each of the other people tested, the increase in oxytocin was in direct proportion to the likely intensity of their emotional engagement in the ceremony. He notes a significant seeming anomaly, that the uptick for the groom’s father was 19% but for the groom, only 13%. Why? Because testosterone interferes with the release of oxytocin, and immediately after the ceremony there had been a 100% spike in the groom’s testosterone level!

Zak also stipulates early in the book that the vast majority of people are essentially primed to follow the Golden Rule (i.e., put another way, that we are essentially “good”), and that “to elicit that naturally occurring, benign behavior all we have to do is to create the circumstances in which oxytocin can exercise its influence, which means, in part, keeping other hormonal influences out of the way.” Later he will mention testosterone in particular as a key hormone that can interfere with oxytocin’s positive effects.

Here is how he summarizes the essence of this work:
“Am I actually saying that a single molecule—and, by the way, a chemical substance that scientists like me can manipulate in the lab—accounts for why some people give freely of themselves and others are coldhearted bastards, why some people cheat and steal and others you can trust with your life, why some husbands are more faithful than others, and, by the way, why women tend to be more generous—and nicer—than men? In a word, yes.”

Fallujah – The Immorality of War

Arguably one of humanity’s most immoral behaviors is war. While The Moral Molecule does not address war directly, Zak’s work on the effects of oxytocin, and its opposite testosterone, clearly are relevant in four notable ways:

• levels of oxytocin and testosterone are not the same in men and women; women have higher levels of oxytocin and, as a sex, show greater levels of empathy;
• there is a relationship between testosterone levels and dominance preoccupation;
• essential human goodness, as facilitated by oxytocin, is the basis for the successful use of nonviolent social transformation;
• human evolutionary success has depended on balance between male and female tendencies, on expression of both male and female dispositions.

How do each of these relate to ending war? First, a key hypothesis of my work is that war is far more disadvantageous for women than it is for men. Consequently, women, much more than men, are more predisposed to avoid going to war or allowing their men to begin wars. Women instead prefer social stability. This sexual asymmetry exists because men can produce great quantities of sperm while women are limited in the numbers of ova and even more restricted in the number of offspring they can bear and raise to be old enough to reproduce the next generation.

To test my proposed “female preference for social stability hypothesis” I suggest, in a just-completed book, that cross-cultural studies on behavioral responses of men and women in a variety of conflict and other situations should not be the same. If I’m right, the results should bear me out. We should find statistically significant differences. And the differences should be such that women’s preferred behavioral choice is something that, in the short- or long-term, will facilitate social stability…the exact opposite of war.

Female Empathy

One such difference should be that women, in general, are more empathetic, more sensitive to the feelings of others, more eager to soothe their feelings. With respect to oxytocin and empathy Zak writes, “…mother ‘love,’ if you will—created the more granular, sensory perceptions that eventually linked oxytocin with empathy. (It also helps explain why females have freer access to both than males. In every experiment I’ve designed for humans, women release more oxytocin than men.”

If someone proposes to launch a war, having empathy for people in the group that might be attacked would be expected to put a brake on the decision to strike a first blow, and presumably woman (as a group) would be expected to feel greater empathy, perhaps especially for the women and children in that other group.

Another difference predicted by the women-prefer-social-stability hypothesis is that in conflict situations women, compared to men, should more often opt for win-win methods of resolution (compromise, negotiation, mediation) as opposed to win-lose methods (fighting to determine a winner and looser).

Win-Win Outcomes Produce More Stable Resolutions

Research and practical experience makes evident that win-win resolutions result in more socially stable outcomes. It would be interesting to see if this sexual difference—which studies have found does exist in western culture—exists cross-culturally, which would indicate that it is an evolved trait that distinguishes women, as a group, from men. And if it does, how is voting in favor of further negotiation instead of a preemptive strike related to an individual’s levels of oxytocin and testosterone at the time of the vote?

The second key point Zak’s work relates to, and that is key to my work, is that war is not an innate, hard-wired “instinct,” but that we do have several hard-wired behaviors that make us vulnerable to it. These built-in traits, in some environmental and cultural contexts, allow a warmonger to build an army. They enable him to convince his people of the need to attack some other group. One of these hard-wired proclivities concerns dominance behavior and the tendency to form dominance hierarchies and to defer to authorities.

Male Preoccupation With Dominance

In a chapter entitled “Bad Boys,” Zak explores bad (and good) behavior associated with testosterone. With testosterone, it is men who exhibit the behaviors he discusses more strongly, as a sex, than do women. For example, men are found cross-culturally to be greater risk takers, and Zak cites research that ties greater risk-taking (in men or women) to higher levels of testosterone.

With respect to making war, a male predisposition to engage in dominance behavior, including construction of dominance hierarchies, allows individuals to build an army. While women also construct dominance hierarchies, theirs are less rigid, and women are much less likely than are men to use physical aggression to build such hierarchies or dominate others.

In warrior cultures, dominance-seeking is encouraged. In egalitarian and nonwarring cultures, building dominance hierarchies and use of aggression in general is suppressed by a variety of means. By revealing chemical differences between men and women in their levels of oxytocin and testosterone, The Moral Molecule gives us a physiological explanation for male/female differences in dominance seeking behavior. War—arguably the ultimate dominance-seeking behavior—is overwhelmingly a male endeavor.

Mohandas Gandhi

A third point I stress, which Zak’s work also addresses indirectly, is that to end the violence that is war, we can’t use violent means. To fight wars thinking that defeating the opposition using force is the means to end war is a proven historical failure. Instead, a movement to end war would require that we use the strategy and tactics of nonviolent social transformation.

This approach to social change has variously been called nonviolent civil disobedience, nonviolent struggle, and nonviolent protest. One of its most skillful modern users, Mohandas Gandhi, gave it the name satyagraha. The method is based on several fundamentals. First, that the objective is not to defeat the opponent, but to win them over, to convince them that what they are doing is harmful (i.e., wrong/immoral).

Standing on the Moral High Ground

This in turn is based on another fundamental to the strategy, which is making sure that the cause being championed is a “just” cause; in the case of war, that the ending-war activists are standing on the higher moral ground.

And a third fundamental upon which the entire method of nonviolent social transformation depends is the belief that all humans are basically good. That if your cause is just, your refusal to use violence will allow you to appeal to your opponents essential human nature, to that “goodness within,” and thereby ultimately to win your opponent to your side. This works because your opponent will “know in their hearts” that they are on the wrong moral side of the issue.

So what is human nature? Is it in fact essentially good? Does it understand, seek, and reward fairness? Or is it, as some religions, philosophies, and economists argue, essentially bad or overwhelmingly selfish?

Zak’s work leads him to the position that we are primed by nature to be pro-social: to be cooperative, to be trusting, to be moral. Deviation from that state, which is the state that results from the flow of the moral molecule oxytocin, is just that….deviation. Our most basic propensity, according to Zak’s work and based on the action of oxytocin, is to follow the Golden Rule. This surely would include the idea that one ought not kill another person who has done you no wrong.

Nonviolent Protest

Nonviolent social struggle, based on working to win over your opponent to your just cause, has been shown to be a powerful transformative agent. The nonviolent  meets its most determined foe only in a dictator or tyrant willing to kill men, women, and children if necessary to retain power, only in individuals who are no longer in touch with their internal moral compass.

Male/Female Balance – the Key to Success

Finally, ending war and making sure we don’t backslide into future rounds of violence will only be possible when men and women are full partners in our governing bodies, and there are many points where Zak points out the need for male/female balance. Not only that it exists in nature, but that it is when our societies are fully expressing this balance of oxytocin and testosterone that we get our best (most adaptive) result.


In the “Bad Boys” chapter he points out how testosterone suits men for their roles in our survival. For example, that testosterone specifically interferes with the uptake of oxytocin, which produces a damping effect on being caring and feeling, seems like a negative. But, says Zak, “it makes young males—hunters and warriors—not only faster and stronger but … less squeamish about crushing skulls in order to feed and protect the family.”

With respect to war, history makes very clear that men alone are unable to free us from this profoundly bad habit/invention/meme. The strong effects of testosterone on male behavior suggest why. It isn’t that men wouldn’t prefer to end this behavior. They are also geared to the Golden Rule.

UN Logo

League of Nations Logo

Throughout history there have been attempts by men to rid us of war. For example, the  League of Nations and the United Nations. The hitch is that over time, male biology works against them. Good efforts and intentions get usurped or morph back into acceptance of the domination of others using violence. If women were sharing in decision-making, as they do in most nonwarring cultures, their oxytocin-fueled proclivities for social stability could help restore our social world to an adaptive balance.

I also point out in an essay entitled “To Abolish War” that it will take men and women in full partnership to end this barbaric behavior. While men alone can’t end war (abundantly evident from the historical record), women alone also can’t end war. The male willingness to embrace revolution, doubtless a willingness fueled by testosterone, will be an essential ingredient in any such campaign.

From the beginning of the book, Zak does make very clear that men and women secrete both oxytocin and testosterone, and that these behavioral traits are found in both sexes. A reader may need to remind himself or herself of this caveat, since individual men and women they personally know may not fit a particular generalization. But significant sexual differences are real, they have enormous influence on our social lives, and they need to be stated clearly, as Zak has done.

For any person interested in the human condition, including what it will take to deliver us from the scourge of war, Paul Zak’s work, entertainingly presented in The Moral Molecule, is a significant, must-read leap forward in answering some of our most fundamental questions about why we do what we do and why we feel the way we feel. And insight into why full partnership of men and women, so that we utilize the best characteristics of both sexes, is a key to creating a better, less violent path for humanity as we move into the future.

[This blog is excerpted from a full book review of The Moral Molecule, which can be found at http://www.afww.org/TheMoralMolecule.html.%5D



  1. Reblogged this on Flip It Right Side Up.

  2. […] tend to intepret sex as more than males do because while it can also be released in men – the presence of testosterone interferes with its […]

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: