• If you want your kids to learn about the physical world, let them play with cups and water; don’t lecture them about the conservation of volume.

• In 1995 I moved to the University of Virginia (UVA) to begin my first job as a professor. Moral psychology was still devoted to the study of moral reasoning. But if you looked beyond developmental psychology, Wilson’s new synthesis was beginning. A few economists, philosophers, and neuroscientists were quietly constructing an alternative approach to morality, one whose foundation was the emotions, and the emotions were assumed to have been shaped by evolution.23 These synthesizers were assisted by the rebirth of sociobiology in 1992 under a new name—evolutionary psychology.

• What, then, is the function of moral reasoning? Does it seem to have been shaped, tuned, and crafted (by natural selection) to help us find the truth, so that we can know the right way to behave and condemn those who behave wrongly? If you believe that, then you are a rationalist, like Plato, Socrates, and Kohlberg.7 Or does moral reasoning seem to have been shaped, tuned, and crafted to help us pursue socially strategic goals, such as guarding our reputations and convincing other people to support us, or our team, in disputes? If you believe that, then you are a Glauconian.

• Our moral thinking is much more like a politician searching for votes than a scientist searching for truth.

• Perkins concluded that “people invest their IQ in buttressing their own case rather than in exploring the entire issue more fully and evenhandedly.”

• All animal brains are designed to create flashes of pleasure when the animal does something important for its survival, and small pulses of the neurotransmitter dopamine in the ventral striatum (and a few other places) are where these good feelings are manufactured.

• Your task is to draw a line that is the same as the line you saw on the previous page, either in absolute terms (same number of centimeters; ignore the new frame) or in relative terms (same proportion relative to the frame). Westerners, and particularly Americans, excel at the absolute task, because they saw the line as an independent object in the first place and stored it separately in memory. East Asians, in contrast, outperform Americans at the relative task, because they automatically perceived and remembered the relationship among the parts.4

• Liberalism seemed so obviously ethical. Liberals marched for peace, workers’ rights, civil rights, and secularism. The Republican Party was (as we saw it) the party of war, big business, racism, and evangelical Christianity.

• We supported liberal policies because we saw the world clearly and wanted to help people, but they supported conservative policies out of pure self-interest (lower my taxes!) or thinly veiled racism (stop funding welfare programs for minorities!). We never considered the possibility that there were alternative moral worlds in which reducing harm (by helping victims) and increasing fairness (by pursuing group-based equality) were not the main goals.27 And if we could not imagine other moralities, then we could not believe that conservatives were as sincere in their moral beliefs as we were in ours.

• “Terrible,” he said, “but at least I’m doing better than the chemist down the street who opened a salt-tasting bar.”

• The two leading ethical theories in Western philosophy were founded by men who were as high as could be on systemizing, and were rather low on empathizing.

• His most important work was titled Introduction to the Principles of Morals and Legislation. In it he proposed that a single principle should govern all reforms, all laws, and even all human actions: the principle of utility, which he defined as “the principle which approves or disapproves of every action whatsoever, according to the tendency which it appears to have to augment or diminish the happiness of the party whose interest is in question.”

• Kant, like Plato, wanted to discover the timeless, changeless form of the Good. He believed that morality had to be the same for all rational creatures, regardless of their cultural or individual proclivities. To discover this timeless form, it simply would not do to use observational methods—to look around the world and see what virtues people happened to pursue. Rather, he said that moral law could only be established by the process of a priori (prior to experience) philosophizing. It had to consist of principles that are inherent in and revealed through the operation of reason.21 And Kant found such a principle: noncontradiction. Rather than offering a concrete rule with some specific content, such as “help the poor” or “honor your parents,” Kant provided an abstract rule from which (he claimed) all other valid moral rules could be derived. He called it the categorical (or unconditional) imperative: “Act only according to that maxim whereby you can at the same time will that it should become a universal law.”

• 23 After reading accounts of Kant’s personal life, however, I think the case is not as clear as it is for Bentham. Kant was widely liked, and he did seem to enjoy company, although some of his socializing had a calculated feel to it (he valued laughter and companionship because they were good for his health).

• I do not want to suggest that utilitarianism and Kantian deontology are incorrect as moral theories just because they were founded by men who may have had Asperger’s syndrome. That would be an ad hominem argument, a logical error, and a mean thing to say. Besides, both utilitarianism and Kantian deontology have been enormously generative in philosophy and public policy. But in psychology our goal is descriptive. We want to discover how the moral mind actually works, not how it ought to work, and that can’t be done by reasoning, math, or logic. It can be done only by observation, and observation is usually keener when informed by empathy.

• Five adaptive challenges stood out most clearly: caring for vulnerable children, forming partnerships with non-kin to reap the benefits of reciprocity, forming coalitions to compete with other coalitions, negotiating status hierarchies, and keeping oneself and one’s kin free from parasites and pathogens, which spread quickly when people live in close proximity to each other.

• Behind every act of altruism, heroism, and human decency you’ll find either selfishness or stupidity. That, at least, is the view long held by many social scientists who accepted the idea that Homo sapiens is really Homo economicus.1 “Economic man” is a simple creature who makes all of life’s choices like a shopper in a supermarket with plenty of time to compare jars of applesauce. If that’s your view of human nature, then it’s easy to create mathematical models of behavior because there’s really just one principle at work: self-interest. People do whatever gets them the most benefit for the lowest cost.

• If you proposed that anything more complex than that was innate—particularly a sex difference—you’d be told that there was a tribe somewhere on Earth that didn’t show the trait, so therefore it’s not innate.

• To replace wiring diagrams, Marcus suggests a better analogy: The brain is like a book, the first draft of which is written by the genes during fetal development. No chapters are complete at birth, and some are just rough outlines waiting to be filled in during childhood. But not a single chapter—be it on sexuality, language, food preferences, or morality—consists of blank pages on which a society can inscribe any conceivable set of words. Marcus’s analogy leads to the best definition of innateness I have ever seen: Nature provides a first draft, which experience then revises. … “Built-in” does not mean unmalleable; it means “organized in advance of experience.”3

• Altruism toward kin is not a puzzle at all. Altruism toward non-kin, on the other hand, has presented one of the longest-running puzzles in the history of evolutionary thinking.13 A big step toward its solution came in 1971 when Robert Trivers published his theory of reciprocal altruism.14 Trivers noted that evolution could create altruists in a species where individuals could remember their prior interactions with other individuals and then limit their current niceness to those who were likely to repay the favor. We humans are obviously just such a species. Trivers proposed that we evolved a set of moral emotions that make us play “tit for tat.” We’re usually nice to people when we first meet them. But after that we’re selective: we cooperate with those who have been nice to us, and we shun those who took advantage of us.

• Everyone cares about fairness, but there are two major kinds. On the left, fairness often implies equality, but on the right it means proportionality—people should be rewarded in proportion to what they contribute, even if that guarantees unequal outcomes.

• We all recognize this portrait of boyhood. The male mind appears to be innately tribal—that is, structured in advance of experience so that boys and men enjoy doing the sorts of things that lead to group cohesion and success in conflicts between groups (including warfare).20 The virtue of loyalty matters a great deal to both sexes, though the objects of loyalty tend to be teams and coalitions for boys, in contrast to two-person relationships for girls.

• Despite some claims by anthropologists in the 1970s, human beings are not the only species that engages in war or kills its own kind. It now appears that chimpanzees guard their territory, raid the territory of rivals, and, if they can pull it off, kill the males of the neighboring group and take their territory and their females.22 And it now appears that warfare has been a constant feature of human life since long before agriculture and private property.23 For millions of years, therefore, our ancestors faced the adaptive challenge of forming and maintaining coalitions that could fend off challenges and attacks from rival groups. We are the descendants of successful tribalists, not their more individualistic cousins.

• Much of the psychology of sports is about expanding the current triggers of the Loyalty foundation so that people can have the pleasures of binding themselves together to pursue harmless trophies. (A trophy is evidence of victory. The urge to take trophies—including body parts from slain foes—is widespread in warfare, occurring even during modern times.)

• Cultures differ in their attitudes toward immigrants, and there is some evidence that liberal and welcoming attitudes are more common in times and places where disease risks are lower.41 Plagues, epidemics, and new diseases are usually brought in by foreigners—as are many new ideas, goods, and technologies—so societies face an analogue of the omnivore’s dilemma, balancing xenophobia and xenophilia.

• For example, small business owners overwhelmingly support the Republican Party57 in part because they resent the government telling them how to run their businesses under its banner of protecting workers, minorities, consumers, and the environment. This helps explain why libertarians have sided with the Republican Party in recent decades. Libertarians care about liberty almost to the exclusion of all other concerns,58 and their conception of liberty is the same as that of the Republicans: it is the right to be left alone, free from government interference.

• A recent study even found that liberal professors give out a narrower range of grades than do conservative professors. Conservative professors are more willing to reward the best students and punish the worst.

• When groups compete, the cohesive, cooperative group usually wins. But within each group, selfish individuals (free riders) come out ahead.

• A fast herd of deer is nothing more than a herd of fast deer.22

• I disagree. Human beings are the giraffes of altruism. We’re one-of-a-kind freaks of nature who occasionally—even if rarely—can be as selfless and team-spirited as bees.

• According to Tomasello, human cognition veered away from that of other primates when our ancestors developed shared intentionality.54 At some point in the last million years, a small group of our ancestors developed the ability to share mental representations of tasks that two or more of them were pursuing together. For example, while foraging, one person pulls down a branch while the other plucks the fruit, and they both share the meal. Chimps never do this. Or while hunting, the pair splits up to approach an animal from both sides.

• In contrast, when early humans began to share intentions, their ability to hunt, gather, raise children, and raid their neighbors increased exponentially. Everyone on the team now had a mental representation of the task, knew that his or her partners shared the same representation, knew when a partner had acted in a way that impeded success or that hogged the spoils, and reacted negatively to such violations. When everyone in a group began to share a common understanding of how things were supposed to be done,and then felt a flash of negativity when any individual violated those expectations, the first moral matrix was born.

• In an interview in 2000, the paleontologist Stephen Jay Gould said that “natural selection has almost become irrelevant in human evolution” because cultural change works “orders of magnitude” faster than genetic change. He next asserted that “there’s been no biological change in humans in 40,000 or 50,000 years. Everything we call culture and civilization we’ve built with the same body and brain.”

• Corporations and corporate law helped England pull out ahead of the rest of the world in the early days of the industrial revolution.

• Communes are usually founded by a group of committed believers who reject the moral matrix of the broader society and want to organize themselves along different principles. For many nineteenth-century communes, the principles were religious; for others they were secular, mostly socialist. Which kind of commune survived longer? Sosis found that the difference was stark: just 6 percent of the secular communes were still functioning twenty years after their founding, compared to 39 percent of the religious communes.

• Even today, markets that require very high trust to function efficiently (such as a diamond market) are often dominated by religiously bound ethnic groups (such as ultra-Orthodox Jews), who have lower transaction and monitoring costs than their secular competitors.

• But even though social class may once have been a good predictor of ideology, that link has been largely broken in modern times, when the rich go both ways (industrialists mostly right, tech billionaires mostly left) and so do the poor (rural poor mostly right, urban poor mostly left). And when political scientists looked into it, they found that self-interest does a remarkably poor job of predicting political attitudes.

• But when liberals try to understand the Reagan narrative, they have a harder time. When I speak to liberal audiences about the three “binding” foundations—Loyalty, Authority, and Sanctity—I find that many in the audience don’t just fail to resonate; they actively reject these concerns as immoral. Loyalty to a group shrinks the moral circle; it is the basis of racism and exclusion, they say. Authority is oppression. Sanctity is religious mumbo-jumbo whose only function is to suppress female sexuality and justify homophobia.

• The results were clear and consistent. Moderates and conservatives were most accurate in their predictions, whether they were pretending to be liberals or conservatives. Liberals were the least accurate, especially those who described themselves as “very liberal.” The biggest errors in the whole study came when liberals answered the Care and Fairness questions while pretending to be conservatives. When faced with questions such as “One of the worst things a person could do is hurt a defenseless animal” or “Justice is the most important requirement for a society,” liberals assumed that conservatives would disagree.

• Based on my own research, I had no choice but to agree with these conservative claims. As I continued to read the writings of conservative intellectuals, from Edmund Burke in the eighteenth century through Friedrich Hayek and Thomas Sowell in the twentieth, I began to see that they had attained a crucial insight into the sociology of morality that I had never encountered before. They understood the importance of what I’ll call moral capital.(Please note that I am praising conservative intellectuals, not the Republican Party.)

• The next time you go to the supermarket, look closely at a can of peas. Think about all the work that went into it—the farmers, truckers, and supermarket employees, the miners and metalworkers who made the can—and think how miraculous it is that you can buy this can for under a dollar. At every step of the way, competition among suppliers rewarded those whose innovations shaved a penny off the cost of getting that can to you. If God is commonly thought to have created the world and then arranged it for our benefit, then the free market (and its invisible hand) is a pretty good candidate for being a god. You can begin to understand why libertarians sometimes have a quasi-religious faith in free markets.

• I find it ironic that liberals generally embrace Darwin and reject “intelligent design” as the explanation for design and adaptation in the natural world, but they don’t embrace Adam Smith as the explanation for design and adaptation in the economic world. They sometimes prefer the “intelligent design” of socialist economies, which often ends in disaster from a utilitarian point of view.

• A graduate student was surprised by my claim that religions are often good for the rest of society, and she said, “But religions are all exclusive!” I asked her what she meant, and she replied: “Well, the Catholic Church won’t accept anyone who doesn’t believe its teachings.” I couldn’t believe she was serious. I pointed out that our graduate program at UVA was more exclusive than the church—we rejected almost all applicants. In the course of our discussion it became clear that her overriding concern was for victims of discrimination, particularly gay people who are told that they don’t belong in many religious communities. Comments such as these convince me that John Lennon captured a common liberal dream in his haunting song “Imagine.” Imagine if there were no countries, and no religion too. If we could just erase the borders and boundaries that divide us, then the world would “be as one.” It’s a vision of heaven for liberals, but conservatives believe it would quickly descend into hell. I think conservatives are on to something.