Every year since 1945, there has been a white-tie fundraising dinner for Catholic Charities held at the lavish Waldorf-Astoria hotel in New York City. This is an elite event where the rich, the powerful, and the famous gather to donate and be seen. In an election year, it is usually the last event during which the two presidential candidates will share a platform before the election. The candidates typically use this forum to deliver humorous speeches and gently roast their competitors and his or her respective party.
In 2000, Al Gore and George W. Bush shared the stage. Gore's joke took a feathery jab at conservative tax policies favoring the rich: “One of my favorite shows is Who Wants to be a Millionaire? Well, it should really be called Who Wants to Be after Taxes a $651,437.70 Person? Of course, that's under my plan. Under Governor Bush's plan it would be Who Wants to Be after Taxes a $701,587.80 Person?”1
The crowd erupted with laughter. George W. Bush followed with a now infamous quote that seemed to flaunt Gore's satirical accusation, which also drew laughs: “This is an impressive crowd—the haves and the have-mores. Some people call you the elite; I call you my base.”
The exchange between Gore and Bush exemplifies the tamest, most playful example that one may ever see of disagreement on the issue of how best to divide resources. Bush was no doubt also taking a poke at himself and his party, however wrapped in truth it may have been. But the remarks touched upon an ancient struggle over resources, one linked to powerful emotion centers in the brain. Perhaps not surprisingly then, Bush's words left many liberals incensed, and the joke was repeated to portray Republicans as greedy, unempathic crony capitalists, including in Michael Moore's 2004 documentary Fahrenheit 9/11. In John Kerry's 2004 run for president, he even used “Haves and Have Mores” as a slogan for the Republican opposition, which he opposed with slogans such as “John Kerry: Leaving Billionaires Behind since 1945.”
Still, these were just words. Concern over the control of resources has historically played out in arenas far more contentious and far more dangerous. Poignant examples include the Communist and Socialist revolutions that have arisen around the world, far more globally than most of us know—in Europe (e.g., France, Russia, Finland, Hungary, Spain, Yugoslavia), Asia (e.g., China, Mongolia, Vietnam, Laos, Malaya, Afghanistan, India), South America (e.g., Cuba, Peru, Nicaragua, El Salvador), Africa (e.g., Ethiopia, Congo), and in many other nations. At their core, all of these leftist revolutions arose in an effort to equalize unequal wealth, and their opposition countered to prevent redistribution. These revolutions have resulted not just in good-natured ribbings but also in mass destruction and rivers of blood.
Political scientists have had no difficulty placing ideological differences on how to distribute wealth along the liberal-conservative continuum. A highly consistent empirical finding is that political liberals tend to favor wealth equalization, whereas conservatives tend to favor the economic status quo. But political ideologies and the economic policy preferences associated with them are only recent expressions of ancient evolutionary imperatives. Thus, our ideology-based economic disputes are usually driven, often unconsciously, by the timeless competition over resources necessary to survive and reproduce. Among humans, as among all social animals, a higher position on the dominance hierarchy affords preferential access to territory, food, and mates. And so, while political science rarely describes socioeconomic stances in evolutionary terms, the struggle to maintain dominance hierarchies, or to equalize them, reflects our long history vying for position in rank-stratified primate social groups. Moreover, if conservatism reflects an “extreme” form of the male brain, and liberalism its inverse, then we would expect to find evidence that conservative economic policy is embedded in male reproductive strategy, and liberal economic policy in female reproductive strategy. Indeed this is exactly what we find.
RANK AND RESOURCE REDISTRIBUTION: THE LIBERAL ENDEAVOR
In evolutionary terms, we can operationalize the liberal position as an effort to restrain dominant men from monopolizing resources, which can impinge on the evolutionary fitness of those with less power. Note my use of gendered language here, for the struggle for dominance and the privileged access to resources that dominance confers are disproportionately a human male concern. This is not to say that women are not or should not be competitive. Women also benefit from higher rank and access to resources, and female-female competition is a widely observed phenomenon across the animal world. But for our entire history as a species, male competition has been far more extreme, more violent, more oppressive, and has resulted in greater power distances than competition between women. Though rarely discussed, these differences are rooted in male reproductive psychology. Liberal egalitarianism, therefore, can be seen as a political strategy to impose limits on male ambitions.
One might imagine this reining in of males is a development of the post-feminist world, but on the contrary, it reflects an enduring prehistoric undertaking. In his study of foraging peoples around the world, anthropologist Christopher Boehm reveals how tribal societies, which are thought to mirror the social environments in which humans evolved, strive to maintain an egalitarian order.2 In small-scale tribal groups, order is achieved largely through cultural taboos designed to keep men from rising up to violently monopolize resources, power, and women.
For example, anthropologist Richard Lee has documented how among the !Kung foragers of the Kalahari desert there is a practice in which men returning to camp after a successful hunt denigrate their own quarry. Writes Lee,
Say that a man has been hunting. He must not come home and announce like a braggart, “I have killed a big one in the bush!” He must first sit down in silence until I or someone else comes up to his fire and asks, “What did you see today?” He replies quietly, “I'm no good at hunting. I saw nothing at all…maybe just a tiny one.”3
The clan follows. When they go in to retrieve the kill they respond, “You mean you have dragged us all the way out here to make us cart home this pile of bones? Oh, if I had known it was this thin, I wouldn't have come. To think I gave up a nice day in the shade for this.”
This practice is an intentional strategy to prevent boastful young males from amassing too much power, according to one tribal member:
When a young man kills much meat, he comes to think of himself as a chief or big man, and he thinks of the rest of us as his servants or inferiors. We can't accept this. We refuse one who boasts, for someday his pride will make him kill somebody. So we always speak of his meat as worthless. In this way we cool his heart and make him gentle.
When cultural taboos among the !Kung fail to prevent an ambitious young man from becoming violent, the group may agree to execute him. Thus while some social scientists will argue the relative egalitarianism among hunter-gatherers reflects our true nature, before humans became corrupted by wealth or Western civilization, the existence of such strident efforts to tamp down male upstarts suggests a different story about who we are. Writes Boehm,
When the subordinates take charge to firmly suppress competition that leads to domination, it takes some effort to keep the political tables turned. For the most part, the mere threat of sanctions (including ostracism and execution) keeps such power seekers in their places. When upstartism does become active, so does the moral community: it unites against those who would usurp the egalitarian order, and usually does so preemptively and assertively.4
Keeping upstart men in check, then, takes vigilance and is not a foolproof effort. Research on hunter-gatherers and horticulturalists—tribes that supplement hunting and gathering with simple gardening—has found strikingly high murder rates and suggests that unequal resource distribution and women-hoarding can arise despite the best efforts of the moral community. For example, some Amazonian Yanomamö men (mostly those who have killed other men in raids5) tend to have more wives and more children, whom they support with food given in tribute by lower-ranking tribesmen.6
Yet, compared to our modern nations of millions, tribe-sized groups are easier to regulate from within. Because hunter-gatherers can't store vast amounts of food to leverage their power base, there are limits to how much wealth and influence they can acquire. When humans began to master agriculture, things changed, drastically. The increased ability to produce and store grains led to a corresponding growth in man's ability to amass power.7 Men used this power to achieve reproductive success in a zero-sum game, and zero-sum games are the root of inequality.
This historical fact about males and fitness inequity has recently been verified by a rather stunning genomic study, which found that humans exhibit far less diversity in Y chromosomes than in X chromosomes. This finding suggests that some ancestral males disproportionately won the struggle to reproduce while others lost out entirely. By analyzing our genome, researchers were able to calculate that for a period after the introduction of agriculture, one man reproduced for every seventeen women.8
It was not unusual for dominant men to code such drastic carnal inequities into law. For example, among the Inca, sexual privilege was carefully allotted according to rank (with high rank typically being synonymous with high material wealth), as described by Felipe Guaman Poma de Ayala:
Caciques or principal persons were given fifty women “for their service and multiplying people in the kingdom.” Huno curaca (leaders of the vassal nations) were given thirty women; guamaninapo (heads of provinces of a hundred thousand) were allotted twenty women; waranga curaca (leaders of a thousand) got fifteen women; piscachuanga camachicoc (over ten) got five; pichicamachicac (over five) got three; and the poor Indian took whatever was left!9
Thus, anthropological, genomic, and historical evidence reveals that male dominance has propelled human inequality since the age of hunter-gatherers, which involves disproportionate access to women, and wealth sometimes measured as simply as greater access to food. Large-scale democracy is only a fairly recent attempt to equalize the vast power differences that so often characterize human social life. America's Founding Fathers expressed this intention plainly in the Declaration of Independence with the seminal words, “We hold these truths to be self-evident, that all men are created equal.” This timeless sentiment occurs throughout the letters and documents of America's first statesmen. Thomas Jefferson went so far as to write, “The foundation on which all [constitutions] are built is the natural equality of man, the denial of every preeminence but that annexed to legal office, and particularly the denial of a preeminence by birth.”10
Other Founding Fathers expressed similar ideas, such as James Madison who wrote, “Equal laws protecting equal rights…the best guarantee of loyalty and love of country.”11 The struggle to redress inequities of power formed the basis of democratic governance, which, having fallen from prominence with ancient Greece, was reintroduced to the world in 1776 in the United States. Here America's Founding Fathers were the moral community, and their efforts to frame the Constitution were a direct response to the monarchic dominance hierarchies that had ruled Europe for centuries, not uncommonly by hoarding wealth and by butchering those who voiced dissent.
But even this historic move was stepwise. The Founding Fathers espoused democracy as a means to achieve equality, yet still enforced rank status by allowing slavery and excluding men of color and (all) women from the political process. Even the Framers, in tendering their radically egalitarian American experiment, could not fully disengage from the primordial male pull to subjugate the rival tribe and oppress women. In light of the competitive reproductive psychology of primate males, this failing makes sense.
Nevertheless, the Founding Fathers’ political descendants have carried their work forward—slavery has been outlawed, women vote and serve in office, and today liberals more strongly support a vast number of social and economic policies all rooted in social egalitarianism: affirmative action; equal pay for women; increasing the minimum wage; increasing taxes for the rich or reducing them for the poor; increased spending on social welfare programs, like welfare, food stamps, unemployment benefits, and Medicaid; socialized medicine; free college education; and equal marriage rights for gays and lesbians (which equalize the economic benefits of being married).
Moreover, liberals have generally favored a government role in enforcing an equal playing field. In 1963, Democratic president Lyndon B. Johnson famously declared to a joint session of Congress, “We have talked long enough in this country about equal rights…. It is time now to write the next chapter, and to write it in the books of law.”12 The next year Johnson indeed signed the Civil Rights Act into law, outlawing racial segregation in schools and discrimination on the basis of race, color, religion, sex, or national origin. Once again, while both sexes engage in discrimination, men historically waged war on outside groups on the basis of race, color, religion, or national origin, or enslaved them, and we all know that laws prohibiting discrimination by sex is meant to protect women from male dominance, rather than the other way around. But the takeaway message here is that the liberal position is an old one, and its egalitarian and feminist flavor reflects the goal of keeping alpha male ambitions in check.
Conservatives, on the other hand, tend to exhibit less support for egalitarian policies and generally oppose legislation granting the government the authority to regulate power and resource differences. This political stance reflects male reproductive psychology, for in terms of fitness men have much more to gain from unequal resource distribution than do women, who have more to gain by resource sharing. This is not to say that all egalitarians are women or that those who prefer dominance hierarchies are only men—they are not. But there is a monumental tilt among males toward inequity, and this tilt is rooted in evolution.
COMPETITION FOR FOOD AND SEX AMONG APES
By considering the behaviors of our closest relatives, chimpanzees, we gain greater insight into how male mate competition formed our own political orientations, into their emphases on hierarchy or equality, as well as their underlying gendered psychologies. In the robust chimpanzee (Pan troglodytes), male alliances are central to survival, particularly in competition with outside troops. It is remarkable how much competition between chimpanzee groups resembles human warfare. Using a cadence reserved exclusively for raids, all-male squads will set off on patrol, moving silently and in single file toward the edges of their territory, scanning the trees and looking out across valleys in search of the enemy.13 When these chimps on patrol find a lone male, or a smaller squad from the rival troop, they will gang up, strike, stomp on, and rip their opponents to death, sometimes biting off genitalia, at other times going so far as to drink the blood of their victims.
Through raiding, male coalitions will expand their existing territory and absorb females of the conquered troop into their own.14 In doing so they not only expand their mating opportunities but also their access to fruit trees and colobus monkeys, a favorite chimpanzee prey species.15 In the world of chimpanzees, there is no egalitarian order between groups—that is, there is no sharing between groups of male chimpanzees; competition for sex and food is normative and brutal, and one group's loss is the other group's gain.
Chimpanzees exhibit in-group competition as well, fueled by a competition for rank and the privileged access to resources that rank provides. Higher-ranking males steal meat more often and are given meat more often by lower-ranking males.16 Dominant males also feed higher in the canopy of trees, where fruit is more plentiful and its sugar content higher. When conflict arises, lower-ranking chimpanzees are pushed down to less bountiful parts of the tree, or off the tree altogether.17 Further, dominant males will monopolize in-group mating whenever they can by attacking rival males or punishing females that stray. In short, there is little egalitarian order within the male-dominated chimpanzee in-group as well. It is worth noting that the “moral community” among robust chimpanzees may also unite to contain male despots—both male and female chimps have been observed forming alliances to overthrow overly aggressive alphas. Sometimes despotic alphas will be killed and even cannibalized.18
Patterns among robust chimpanzees suggest a common root with political conservatism among humans. Their societies are male dominated, highly stratified, xenophobic, and warlike. They compete with outside troops and seek to monopolize food and mating. By contrast, our other chimpanzee cousins, bonobos (Pan paniscus), differ from robust chimpanzees in ways that resemble political liberalism. Bonobo societies are female-led, egalitarian, open to outside groups, and largely peaceable. There is little competition between bonobo groups, and groups often eat and mate relatively freely with one another.
How do we understand such radical differences between our respective cousins? Competition for resources. Unlike that of the robust chimpanzees, bonobo territory does not interweave with that of gorillas. Separated from gorillas by the Zaïre River, bonobos have more access to foods normally consumed by their colossal cousins. Thus one critical reason that male bonobos don't wage war on one another, why they can afford to be female oriented, egalitarian, and “liberal,” appears to be that their opulent food supply doesn't force violent competition. Or as primatologists Richard Wrangham and Dale Peterson put it, “Bonobos have evolved in a forest that is kindlier in its food supply, and that allows them to be kindly, too.”19 Conversely, robust chimpanzees were pressured to adapt to the overall less available plant life. They did so by becoming male dominated and militaristic, and by conducting raids on rivaling troops to secure greater resources for the in-group. This male orientation pushed male reproductive imperatives to the foreground, and chimpanzees evolved to be more sexually controlling and competitive than bonobos. And so, among our closest primate relatives, both “liberal” egalitarianism and “conservative” allegiance to male social hierarchies appear to have been driven by male competition (or the relative lack of male competition) for natural resources.
COMPETITION FOR FOOD AND SEX AMONG MEN
It should come as no surprise, then, to find that competition has shaped human political psychology in similar ways. It is only recently that humans have mastered food production such that billions can survive with little fear of starvation. But feeding ourselves was not always so easy in our ancestral past. Archaeological evidence suggests that periods of scarcity caused by environmental change or population explosions were not uncommon and compelled intergroup conflict and warfare among our prehistoric ancestors.20 And so, even though many of us now live in societies that produce staggering surpluses of food—not to mention epidemics of morbid obesity—our brains evolved amid the very real threat of starvation. This may be why conservatives living in obscenely overfed nations can still experience intense emotion over policies related to the distribution of food, such as welfare subsidies or food stamps, which in the United States are often utilized more by racial minority groups.21 It is probably no coincidence, then, that negative attitudes about outside races robustly predict opposition to welfare programs.22 Moreover, as with chimpanzees, warring with outside groups to control food sources has always been the enterprise of male humans. Thus the xenophobic, male tenor of conservative economic policies reflects a history of fighting with outsiders for the privilege to eat.
Evolutionary fitness, however, is not achieved by bread alone. Like other male primates, men also compete for mates, and the dynamics of male mate competition are equally relevant in understanding political orientation. To make sense of how mate competition forms the conservative stance, it is necessary to understand that men and women employ markedly different mating strategies.
MEN AND THEIR NUMBERS STRATEGY
Sex-based reproductive strategy differences are based in part on differences in potential reproductive output. Like the male chimpanzees, and males of many other species, men can exponentially increase their genetic fitness (i.e., their number of offspring) by mating with as many women as possible. This is not the only available strategy—some men will pair bond with their wives, devote virtually all their time, energy, and resources to rearing their offspring, and swear off sex with other women. Other men are terminal philanderers. Innumerable men lie somewhere in between. But the algorithmic advantage to male genes coding for a preference for sexual numbers is without question, whereas the reverse is largely not true for women. For this reason, men generally tend to prefer a variety of casual sexual partners. Women, on the other hand, generally tend to prefer stable, committed relationships with partners willing and able to contribute resources to childrearing, which requires extended provisioning.
Parental investment also drives these differences. Biologically, men invest about a teaspoon of semen and theoretically can walk away after that. But women spend nine months in pregnancy, endure risky childbirths, and generally continue to provide the majority of parental caregiving across the globe. Further, sperm is cheap and produced by the millions, whereas ova are scarce, released only during the period from adolescence to menopause (about five hundred total across a woman's life span). This scarcity drives female selectivity, as does the need for quality, committed mates who can provide resources.
Evolutionary psychologist David Buss has conducted surveys among tens of thousands of people, drawn from across cultures, religions, race, socioeconomic status, and every continent on the globe, and found repeatedly that men prefer casual sex and more sexual partners more than women (endorsing a quantity strategy), and that women prefer resource investment about twice as much as men (reflecting a quality strategy).23 In one study, Buss found that out of sixty-seven potentially desirable traits in the partner of a casual affair, men had lower standards than women on forty-one of them. Buss writes that men “require lower levels of such assets as charm, athleticism, education, generosity, honesty, independence, kindness, intellectuality, loyalty, sense of humor, sociability, wealth, responsibility, spontaneity, cooperativeness, and emotional stability.”
When asked about undesirable traits, men had fewer problems with “mental abuse, violence, bisexuality, dislike by others, excessive drinking, ignorance, lack of education, possessiveness, promiscuity, selfishness, lack of humor, and lack of sensuality.” In fact, men rated only four characteristics as less desirable than did women: “low sex drive, physical unattractiveness, need for commitment, and hairiness,” all of which speak to potential problems in fertility, or, as in the case of the need for commitment, an impediment to the quantity strategy.24
Other researchers have set up scenarios where attractive confederates approach the opposite sex and promptly offer casual sex. Seventy-five percent of men accepted the offer, compared with none of the women.25 Research has also found that men fantasize more than women about group sex,26 and that men are four times more likely than women to fantasize about having sex with over one thousand different partners throughout their lives.27 Men, on the whole, appear hardwired to prefer a shotgun-blast approach to reproduction.
The problem with all this male readiness, however, is that in any given population, there are fewer sexually receptive females than there are males. The sex ratio, the number of men to women, is roughly one to one worldwide (slightly favoring men). But the operational sex ratio (OSR), or the number of reproductively viable males competing to reproduce as compared to the number of reproductively viable competing females, tends to skew much higher on the male end. There are a variety of reasons for this difference, including men's longer span of reproductive viability and the fact that many women are already reproductively committed (e.g., pregnant or nursing) at any given time. Add the fact that, when possible, powerful men will engage in polygyny and the reproductive future for low-ranking men looks increasingly bleak. For men, these factors create scarcity and the risk of total reproductive failure. Like chimpanzees, and males of many species, men will use violence as a strategy to secure scarce resources, including access to mates.
HOW NUMBERS STRATEGIES DRIVE INEQUALITY
While political discourse usually measures inequality in terms of economic wealth rather than access to women, reproductive resources are competed for just the same. Moreover, wealth for men has traditionally been a vehicle for attracting mates. Indeed, a highly robust research finding is that men with more resources have better mating prospects.28 Female selectivity and the need for resources, in turn, accelerate male competition—for women and for the resources required to attract them. But economic resources are also finite, meaning some men end up with more than others. And since men have more to gain from wealth in terms of reproductive fitness than women, men have a greater evolutionary incentive to prefer economic inequality. Thus the male-dominated, economically competitive orientation of political conservatism reflects a male reproductive strategy.
We have seen how male chimpanzees use violence to outcompete rival troops for access to mates. Is there evidence that mate competition could possibly drive human violence and inequality? The archaeological and historical records leave no doubt. For example, archaeologists excavated a seven-thousand-year-old massacre site in Austria from the Neolithic Age, and found that the remains of reproductive-aged women were notably absent amid the bashed-up skulls and bones, suggesting that young women were not killed but taken captive.29 Fast-forward to the Dark Ages, and the great historian William Durant has described how during the Crusades Christian men were lured to fight Muslims with the promise of great riches and “dark beauties” as their prize of war.30
A historical exemplar of wealth and reproductive inequality is Moulay Ismail ibn Sharif, a warrior king who ruled Morocco from 1672 thru 1727 with such brutality that he was nicknamed “Ismail the Bloodthirsty.” History books assure us that he earned his moniker; Ismael is reputed to have ordered that the heads of ten thousand enemy (male) combatants adorn the walls of his city.31 Moreover, by attacking neighboring territories, killing or enslaving the men, and appropriating their riches, he managed to acquire five hundred concubines and sire 888 children.32 The wealth he wrenched from neighboring peoples not only supported his expansive harem, and mind-boggling number of children, but also fed his armies, fortified his cities, and built his empire, all of which served to ensure his reproductive dominance over other men.
One could fill an entire book with examples. Laura Betzig did just that in her book Despotism and Differential Reproduction.33 Betzig studied 104 societies, across every continent on the globe, and found that when men amass power and wealth, they have predictably created despotic laws that support continued success in the male numbers strategy—most directly by making rules to funnel women their way and to ensure the wealth required to support and contain their sexual prizes. Betzig identifies how strategies such as these have resulted in harems ranging from two to literally thousands of women. Like male chimpanzees attacking genitalia, history's despots have often made laws allowing them to castrate lower-ranking males—surgically eliminating them as sexual competitors.
In the modern day, another example is provided by the Islamic State of Iraq and Syria (ISIS), by all accounts an extreme conservative political movement. Although making claims to religious ideology, ISIS competes for both economic and sexual resources. Here Newsweek provides a summary of their economic exploits:
The ISIS economy and its fighters predominantly rely on the production and sale of seized energy assets—Iraq has the fifth-largest proven crude oil reserves in the world. ISIS also depends on the steady income it extracts from private donors, the heavy taxation and extortion it levies on its captive population, the seizure of bank accounts and private assets in the lands it occupies, ransoms from kidnappings and the plundering of antiquities excavated from ancient palaces and archaeological sites.34
Clearly, pilfering in war is not a gesture of between-group egalitarianism. But when ISIS rampaged across northern Iraq, slaughtered all the men, and took Yazidi tribeswomen as sexual slaves, they revealed the desire for a far more ancient resource than money. These attacks, like so many others, were the epitome of male mate competition. One journalist reported how the men of ISIS systematically targeted not only grown men but also any young boys who showed secondary sex characteristics. In evolutionary terms, these boys had made the transition from children to male sexual competitors. Having achieved this developmental milestone was a death sentence:
Adolescent boys were told to lift up their shirts, and if they had armpit hair they were directed to join their older brothers and fathers. In village after village the men and older boys were driven and marched to nearby fields, where they were forced to lie down in the dirt and sprayed with automatic fire.35
Tellingly, ISIS also hired gynecologists to determine whether their Yazidi sex slaves were pregnant at the time of their capture and forced those who were to have abortions, thus eradicating the genes of rival males.36 Horrifying as they are, these are the exact patterns we would expect to see among a group of warring male primates.
Such patterns can be elicited among men living peaceful civilian lives. In one study, young men attending a Chinese university were shown full body images of women rated as attractive or unattractive.37 After this, they were given a series of questions about making war with other countries. Men who viewed the attractive female photos “showed more militant attitudes,” according to the researchers. This effect was not seen among women. In another experiment in the same study, the researchers showed men a photo of either a woman's legs or a Chinese flag. Subjects then were measured on how quickly they responded to either words related to war or words about innocuous stimuli such as “farms.” Seeing women's legs made men respond more quickly to war-related words than seeing a flag, suggesting that even civilian men during peacetime are primed for violent competition for mates.
With an understanding of the male mate competition, we can begin to illuminate the ultimate roots of political inequality and male-oriented conservatism. Unequal economic wealth and power continues to result in reproductive bonanzas for men. The same is not true for women—women could not achieve the same reproductive windfalls by tearing into rival villages, killing rival women, taking their goods, and having sex with as many men as possible. The evolutionary incentive for men, however, is abundantly clear.
Men will fight for greater resources, be they wealth or women, and striking research is beginning to bring the links between inequality, male mate competition, and political conservatism into even sharper focus. One study found that higher upper body muscularity in men was associated with a greater sense of entitlement, as measured by agreement on responses to statements such as, “I deserve more than the average person.”38 Greater muscularity in this study was also associated with less egalitarian attitudes, less likelihood to share resources in a laboratory game, higher competitiveness, and higher social dominance orientation, which, once again, is a preference for social inequality strongly associated with political conservatism. These relationships were not found in women, and women were less likely to endorse these attitudes than men across all of the measures. Other research has found that men with higher endogenous testosterone,39 as well as men who were administered testosterone,40 are less likely to share money in laboratory games. Notably, the same hormone associated with resource hoarding wealth also increases muscle mass and underlies both aggression and sex drives. Thus the staunch conservative opposition to policy that levels the playing field—such as social welfare programs, affirmative action, or taxing the rich—emits a distinctive male musk that links back to a time when our hirsute male ancestors were physically competing for scarce resources on the savage savannas in which we evolved.
It is not difficult to see male mate competition expressed more vocally among conservatives, and with our evolutionary insights, we can see how such mate competition underlays conservative xenophobia. Male KKK members, who have notoriously engaged in the most bestial means of mate competition—threatening to castrate black men,41 or actually perpetrating the crime42—strongly endorsed Republican candidate Donald Trump in the 2016 US presidential election. Part of Trump's appeal to xenophobic men was that he made promises that tap into the ancient primate male concern over reproductive rivalry, particularly with outside men, like when he vowed to build a wall to keep out Mexican “rapists.”
During the same period, Maine Republican governor Paul LePage (a white man) described the heroin trade in his home state: “The traffickers…these are guys by the name D-Money, Smoothie, Shifty [stereotyped names for black men]. These types of guys that come from Connecticut and New York. They come up here, they sell their heroin, and they go back home…incidentally, half the time they impregnate a young white girl before they leave.”43 Here there is no question that LePage saw black men as part of the outside tribe, and that his impulse was to block them from sex with women from his in-group.
But the key insight is that our male ancestors have competed for food, territory, and ultimately females in zero-sum competitions since before we were even fully human. Today, conservatism's male and inegalitarian tenor embodies our male primate ancestry's competitive struggles. While those struggles reflect competition for rank within groups, they prominently reflect group-based dominance struggles. Interestingly, central constructs in political science research have unwittingly tapped into these ancient competitions. Here I explain social dominance orientation and its deep roots in male coalitionary violence.
SOCIAL DOMINANCE ORIENTATION
Men like Trump and LePage have managed to epitomize primate out-group competition, and political scientists have developed a scale to measure it called social dominance orientation (SDO). Essentially, SDO reflects the extent to which an individual wishes his or her group to be dominant over another (versus the extent to which he or she prefers intergroup relations to be equal). The authors of the SDO scale explain that “people who are more social dominance oriented will tend to favor hierarchy-enhancing ideologies and policies, whereas those lower on SDO will tend to favor hierarchy-attenuating ideologies and policies.”44 SDO has been consistently found to predict political conservatism and its corollaries, including economic conservatism and racial prejudice.45
Important for our gendered political brain hypothesis is a robust finding that men score higher on SDO than women. This difference holds across age, culture, nationality, religion, income level, educational attainment, and political ideology.46 Researchers have attempted to determine whether higher SDO among men can be accounted for by their higher status, which is the norm in most human societies. However, sex differences in SDO remain stable across cultures that vary greatly in terms of women's social standing—across the highly divergent cultures of Palestine and Southern California, for example.47 With its male concentration, it is perhaps not surprising that those with high SDO are more likely to support war,48 the most profound and violent means of establishing male dominance over other male groups, or preventing domination by them. Because primate male dominance struggles occur within groups as well, SDO also has implications for domestic policy, particularly around issues concerning access to resources and sexual control of women. For example, SDO correlates negatively with affirmative action, social welfare programs,49 and support for women's rights,50 which often concern women's sexual freedom.
It may seem strange that SDO, which measures in-group preference, predicts bias even against those with a shared national identity—why seek to keep resources from other Americans? However, competition between subgroups within a nation's borders reflects ancient adaptations for out-group competition. The human brain evolved in small, close-knit, competing bands of people, and evidence suggests that it remains calibrated to process social information within tribe-sized alliances topping out at around 150 individuals.51 Fighting units in modern militaries, for example, mirror the group sizes of early hominids,52 as do farming communities, business organizations, and many other social groups. When groups exceed those sizes, social cohesion and organization tend to break down.53
What this means is that even though citizens technically share a national identity, our brains may have difficulty recognizing an in-group that is millions of times larger than the small band sizes in which we evolved. Instead, our Stone Age brains—already sensitive to signals of out-group difference—often encourage us to form smaller, competing groups within our national boundaries. Thus the ease with which nations can become divided between blacks and whites, Arians and Jews, Hutus and Tutsis, Sunni and Shia, Southerners and Yankees, Republicans and Democrats, rich and poor, and so on.
It may also seem strange that people of marginalized groups can become conservatives, given that conservatives tend to be higher on SDO, more xenophobic, and opposed to policies that would level the playing field for those very same groups on the margins. Here there are two important points to understand. Political orientation and its corollaries, such as SDO, are not set like eye color or some other static trait—rather, like many other adaptations they are malleable but with a predilection toward one strategy over another. This malleability allows humans to adapt to changing social, hierarchical, and environmental circumstances. Most psychological traits exhibit this kind of (limited) flexibility.
Accordingly, we also find differences in SDO according to position in the hierarchy. Meta-analytic research has found that people belonging to lower-ranking gender and ethnic or racial groups tend to reject group-based social dominance, whereas those in higher-ranking groups tend to favor social dominance.54 Low SDO would allow someone in a subordinated position to reject the dominance hierarchy or to level the playing field by constraining dominance hierarchies altogether.
But an alternate strategy one may choose to join the prevailing dominance hierarchy even in a subordinated position (people of color, women voting for Trump, for example). Even at a cost to fitness, doing so can be a better choice than standing with a weaker (albeit more egalitarian) alliance that is more vulnerable to total annihilation by outsiders. Research finds, for example, that those near the World Trade Center during the 9/11 attacks reported growing more politically conservative, rather than more liberal, after the attacks.55 This shift occurred across party lines and was associated with both greater patriotism and militarism. Thus, SDO, like our political orientations, is neither completely pliant nor completely rigid—it has the capacity to flex.
Another crucial point to remember is that social dominance is not only about disfavoring the out-group but also favoring the in-group. Accordingly, SDO is associated with greater patriotism,56 which, not surprisingly, is more strongly expressed by Republicans.57 Beyond the national flags, the parades, and the anthems, patriotism is essentially a commitment to the tribe, particularly in competition with outsiders. The ubiquity of SDO across the world underscores the fact that we navigate through our increasingly globally interfaced world, using the narrow parameters of our tribalistic brains. This mismatch poses certain challenges.
One challenge is that SDO is associated with the belief that one's group is inherently better than others, and also predicts support for intergroup aggression.58 Humans share this pattern of in-group altruism and out-group enmity with robust chimpanzees. Jane Goodall observed that “as a result of a unique combination of strong affiliative bonds between adult males on the one hand and an unusually hostile and violently aggressive attitude toward nongroup individuals on the other,” the chimpanzee “has clearly reached a stage where he stands at the very threshold of human achievement in destruction, cruelty, and planned intergroup conflict.”59 Among humans, tribalism is also at the root of societies being torn apart from the inside, along sectarian, racial, ethnic, or partisan lines. But once again, we typically find male competition at the center of human divisions, whether between nations or tribesmen, and in turn, we find genetic processes at the center of male competition.
SHARED GENES, SDO, AND MALE VIOLENCE
As Ismael the Bloodthirsty's five hundred concubines and 888 children evince, men are driven by personal reproductive ambitions. However, amassing power requires alliances. Moreover, because men in more violent times stood the risk of being annihilated by rival male groups, they had great incentive to form warring coalitions. Men unable to do so would be ground into dust. This dynamic, which makes the maxim join or die a rather literal evolutionary imperative, forged a powerful selective pressure. And so today we see group-level violence between men across many levels of human social organization, from intertribal conflicts to gang fights to world wars.60
While rarely discussed, shared genes have a role in male intergroup conflict. British biologist Richard Dawkins popularized the idea of a gene-centric view of evolution in his book The Selfish Gene.61 Dawkins explained how genes design organisms in ways that maximize their own reproduction, and went so far as to say that organisms are the “survival machines” of genes. One common means of understanding this relationship is by considering the impact of genes in acts of altruism—acts that may endanger the life of one individual in the service of helping another. The willingness to perform such acts is generally highly correlated with the amount of shared genetic material. Hypothetically, if I were going to save someone from a burning building, I would save my child first, my cousin next, an unrelated stranger after that, and I might just leave my pet goldfish to boil—or, as British geneticist J. B. S. Haldane famously said, “I would lay down my life for two brothers or eight cousins.”62 Thus genes code brains to engage in behaviors that ensure more copies of themselves get passed on across time, even if those genes reside in others. That said, when I burst into a burning building, I'm not consciously thinking of my genes. But my genes make my brain experience an intense sense of emotional, cognitive, and moral urgency to save my child first.
Patterns of migration appear to have intensified moral commitments between men. Historically, humans have been mostly patrilocal, meaning women have left their natal group far more often than men, whereas men stayed put along with their male relatives. Research has found that up to 70 percent of all human societies follow this pattern of emigration.63 The resulting concentration of male blood relatives encouraged naturally strong, trusting, and cooperative male bonds based on shared genes. Accordingly, across human history, men have had stronger kinship ties than women.64 The love and trust that related men have for one another has had profound implications for the human condition across time.
For one, higher relatedness gives men greater confidence in risky cooperative enterprises, such as war, with closer kinship providing genetic incentive to take risks in defending one another. As a corollary, research has found that patrilocality in human groups is associated with more frequent warfare.65 This too is a pattern that human males share with our chimpanzee cousins. Renowned primatologists Richard Wrangham and Dale Peterson write that among four thousand mammals, and over ten million other animal species, only chimpanzees and humans follow this pattern of patrilocality accompanied by “a system of intense, male initiated territorial aggression, including lethal raiding into neighboring communities in search of vulnerable enemies to attack and kill.”66
Further, the hostility created by patrilocality locks us into patrilocality. Chimpanzee males, for example, are so extremely hostile toward outside males that males rarely if ever transfer between groups; any male attempting to transfer would be summarily killed by the males of the out-group. By contrast, 50–90 percent of female chimpanzees transfer to other groups to breed once they reach sexual maturity.67 Whereas male transfers are seen as sexual competitors carrying foreign genes, females are welcomed as potential mating partners.
Male transfer is more common among humans than chimpanzees but still not the predominant pattern—like male chimps, men are hostile to strange men. Thus xenophobia is concentrated among men, and it has reflected real dangers for men. Most of the world's perpetrators of violence are men, but most of its victims are as well (the United Nations, for example, recently found that globally 80 percent of homicide victims are men68), and this pattern of killing is very old. Male-on-male violence persists particularly among humans living in groups similar to those of our ancestors. Archaeologist Lawrence Keeley examined contemporary foragers across the world, such as the Jivaro, Yanomamö, Mae Enga, Dugum Dani, Murngin, Huli, and Gubs, and found that male-on-male violence accounted for a whopping 30 percent of all male deaths.69 If this population of men were all five boroughs of New York City, roughly the population of Brooklyn would be annihilated. The resulting fear of out-group males perpetuates the cycle of violence, for, as we learned in chapter 2, xenophobia promotes inbreeding. Inbreeding increases the degree of shared genes in a population, which in turn increases xenophobia, further locking humans into patrilocal, xenophobic, patriotic groups of violently competing male primates.
The cycle of xenophobia has held strong even with our shared genes thinning out as populations swell. Military men exaggerate genetic relatedness by calling themselves “brothers-in-arms” fighting for their “fatherland” or “motherland.” And fighting men have reported feeling closer to their fellow soldiers than to their own wives,70 which suggests that our long history of patrilocality may have greased the way for contemporary male tribalism. Even modern-day men living as civilians in peaceable societies have the tendency to fall back into these patterns, which have proven easy to elicit in the research lab. When experimenters posit an outside threat, men close ranks, identify with their group, and start cooperating more, whereas this response is generally not found among women.71
An important point in all this is that if ancestral human men couldn't leave their groups for fear of death, then turning inward to their band of brothers, remaining xenophobic toward outsiders, and favoring dominance over other groups was evolutionarily sensible. The overrepresentation of men among conservatives and the preponderance of male interests embedded in conservative ideologies, then, reflect these ancient selection pressures on men.
Certainly, in a dangerous world, with groups of men amassed on the border, waiting to annihilate my tribe, I would want to be surrounded by a close-knit, aggressive, xenophobic tribe of men. Similarly, if my children and I risked starving to death without access to a contested resource, I would want my tribe to win control. Once again, the question remains, however, how much utility this psychology retains as we move from small tribes competing for scarce resources to an interconnected community of nations, bound by a global economy, and with the technological capacity to erase starvation from the human experience.
Moreover, evolutionary science teaches us that inequality is often driven by the personal reproductive ambitions of men. Man's exorbitant reproductive capacity has given him incentive to disproportionately hoard power, wealth, and women, and, when allowed, to use despotic violence as a means to this end. So the impulse to extract wealth from the rival tribe is about not only survival but also feeding insatiable male reproductive greed. When we understand these roots of inequality, we may begin to question how far we allow them to influence our economic policy. But merely posing this question can be challenging. Across our history, powerful men have achieved godlike status in their roles as protectors, or as oppressors, which has made questioning their methods both risky and emotionally complex. The next chapter will explore why.