Why do we fall in love, feel jealous, compete for status, or sacrifice for family? Robert Wright’s The Moral Animal offers a theory: These behaviors are hardwired into us by evolution.
Published in 1994, this book connects biology, anthropology, and psychology in an attempt to explain everything from romantic attraction to moral judgment. Keep reading to see how understanding our evolutionary programming might help us make sense of our own motivations and better understand the people around us.
Overview of The Moral Animal by Robert Wright
In The Moral Animal, Robert Wright uses evolutionary psychology to explain the hidden forces driving human behavior. Drawing from research in biology, anthropology, and psychology, Wright argues that our minds and social instincts were shaped by natural selection to maximize reproductive success in our ancestral environments and these ancient programming patterns continue to influence everything from our romantic relationships to our moral judgments today. This evolutionary lens helps explain human behaviors that appear across all cultures, such as status-seeking, jealousy, friendship, and family dynamics.
A journalist, Wright argues in this 1994 book that, by understanding the role of instinct in our daily lives, we can become more aware of our own motivations and more understanding of others. Our overview explores the book’s ideas in five parts.
Part 1: Evolution Explains Human Behavior lays out the framework for Wright’s ideas, exploring the role of evolution in creating our emotions and unconscious responses.
Part 2: Reproductive Behaviors explores how people seek romantic partners and how evolutionary forces shape marital customs across cultures.
Part 3: Family Ties takes a closer look at how evolution has shaped the way people behave toward family members, from self-sacrificing behaviors to sibling rivalries.
Part 4: Social Instincts covers how evolution affects the way we navigate our respective societies by forming friendships, seeking social status, and maintaining our reputations.
Part 5: Implications dives into Wright’s argument that an evolutionary outlook should reshape our understanding of psychology and ethics.
Part 1: Evolution Explains Human Behavior
Wright argues that we can best understand human behavior by examining how natural selection designed our minds and social instincts. He emphasizes that humans aren’t blank slates shaped entirely by culture; rather, we have an inherent nature shaped by evolution. Beneath our cultural differences lie universal human patterns and predispositions. For example, people everywhere care about social status, engage in gossip about similar topics, experience guilt in predictable circumstances, and have an innate sense of fairness and reciprocity.
Wright explains that such commonalities exist because they were adaptive during our evolutionary history. Any genetically-based instinct or impulse that provided even a marginally better chance of reproduction would enable its carriers to produce healthy offspring—offspring who would carry this beneficial gene themselves. This would in turn increase the offspring’s chance of survival and reproduction, so over time, more and more of the population would carry this gene. In other words, universal patterns of behavior are rooted in the human drive to gain a reproductive advantage. In this section, we’ll explore how evolution shaped our emotions and unconscious drives, and the environments that molded them.
Evolution Shaped Our Emotions
Wright argues that evolutionary forces shape behavior through unconscious drives and emotions. He clarifies that humans aren’t necessarily spending all day thinking about how to strategically maximize their chance of reproducing. Rather, they react to the world with a toolkit of emotional responses that were designed by evolution to maximize our odds of survival and reproduction. Therefore, universal human emotions such as romantic love, jealousy, parental love, embarrassment, and shame were all shaped because of the contributions they made to reproductive success.
Evolution Shaped Us for an Ancestral Environment
Wright also explains that our emotions evolved in ancestral environments very different from today’s world. For most of human history, our ancestors lived as hunters and gatherers in small bands of 50 to 150 people. They developed drives, emotions, and behaviors that made evolutionary sense in that context but may be counterproductive now. For example, our craving for sugar and fat was adaptive when those resources were rare but leads to obesity in modern environments of abundance.
Though the type of social arrangements people have lived under may have changed throughout the years, humans have always lived among other humans. As a result, people have very strong instincts relating to how they interact with others. Wright argues that instincts determine how people cooperate, compete, form bonds, and choose romantic partners, and he focuses most of his book on how humans behave toward and around other people.
Next, we’ll explore how these instincts shape mating behavior and marriage systems.
Part 2: Mating and Marriage
Wright argues that evolution has shaped our reproductive behavior to increase the chances of producing offspring that are healthy enough to make it to adulthood and reproduce themselves, carrying genes into the next generation. Here we’ll explore these behaviors in two parts: reproductive strategies for men and women, and marriage practices.
Reproductive Strategies for Men and Women
Wright explains that reproductive strategies for men and women are shaped by differences in the investment required to reproduce. In general, raising an infant takes a lot of effort, calories, and time. Compared to other great apes, humans are born relatively helpless and require extensive care. This is likely because, as humans evolved to walk upright, their pelvises shrank, requiring them to give birth earlier. As a result, human infants are smaller and less capable than other newborn primates.
However, the minimum level of investment required for reproduction is different for men and women. To reproduce, a woman needs to carry the pregnancy and then nurse the child. In contrast, a man only needs to impregnate a woman—and from there, he may not always play as essential a role in the offspring’s survival. Because of these differences, men and women approach mate selection differently.
Women’s Reproductive Strategies
Because women have to make such a high investment of time, energy, and calories, they’ve historically had a higher rate of reproductive success by being highly selective and vetting potential partners before mating. Vetting provides three advantages:
First, vetting helps women secure the best possible genes for their child. By choosing to mate with a man whose genes are thriving in the current environment, she increases the likelihood that her offspring will thrive in that environment as well.
Second, vetting allows women to select men with more access to resources such as wealth and food. Because raising a child requires consistent access to food, those who selected men with more resources—or character traits that lead to resources, such as industriousness and ambition—were more likely to pass on their genes because their children had a steady supply of things to eat.
Lastly, vetting allowed women to pass on their genes at a higher rate if they selected partners based on commitment. This is because men who were committed to one partner would provide more resources to her children than a man who was dividing his resources between the children of several partners.
Men’s Reproductive Strategies
Wright explains that men’s reproductive strategies are also shaped by the behaviors that led to reproductive success in the past. Because of the high investment required to take care of a human infant, men (on average) invest more time and energy into parenting than other great apes such as chimpanzees, gorillas, and orangutans.
However, because men have to invest far less effort in reproduction than women, they’ve historically achieved reproductive success by pursuing multiple partners and opportunities for casual sex without commitment. According to Wright, men across cultures tend to be more interested in pursuing casual sex than women.
Furthermore, men have historically had more reproductive success when pursuing women who have higher fertility. Younger, healthier women have more years of fertility ahead of them, and this makes them a better bet for a man’s reproductive investment. Therefore, men use visual cues to discern whether partners are youthful and healthy (and place a higher emphasis on physical appearance when selecting mates).
Flexibility in Strategies
Wright maintains that reproductive strategies vary situationally, depending on status and resources, and that a person might use several different strategies at different times throughout their life.
To illustrate how reproductive strategies might vary, Wright says women are more likely to choose more than one partner in societies where resources are low and one partner may not be able to contribute much to their children. Or she might use a deceptive strategy, selecting the genes from one man and the resources and paternal investment of another.
Men may also pursue a mixed strategy of commitment and casual sex, having one primary partner but cultivating casual partners on the side. For example, a wealthy man may invest most of his resources in his wife’s children but maintain a relationship with a mistress as well. Men may also use deceptive strategies, feigning commitment when they’re actually more interested in casual sex.
Competition and Jealousy
Wright explains that evolution also shaped competition and jealousy within genders. Competition is the result of scarcity. If more than one person wants to mate with the same partner, but only one can do so, then each one stands to gain by outcompeting the other.
Wright explains that men tend to compete more against other men than women compete with other women, because a woman’s reproductive investment is a scarcer resource than a man’s. (A woman can only have about one baby per year, but a man can impregnate countless women in the same amount of time.) However, because human men invest more in their offspring than males in other species of apes, women are more competitive and jealous with each other than females in many other primate species.
Marriage Practices
If all humans have the same set of social and reproductive instincts, then why do marriage practices differ so much between cultures? Wright argues that human mating instincts exist within economic conditions, and the expression of mating instincts will change in response to those conditions. He explores three different marital practices and analyzes how they relate to a society’s distribution of resources.
1) Monogamy
Monogamy is the practice of each man and woman taking only one partner. Wright argues that monogamy is most commonly found in societies with a relatively equal distribution of resources. This is because there is very little incentive for a woman to choose a husband who is already married, since she can easily get more resources for her offspring by choosing a comparable unmarried partner. So, men are not able to attract multiple wives in the first place.
Monogamy is also the norm in some societies with a highly unequal distribution of resources. This is the case throughout Western societies, which Wright argues are the exception to the rule. He points out that monogamy in these societies is strenuously enforced through social pressure—but frequently violated. Strong social taboos are required to keep reproductive behavior monogamous, but many high-status men will circumvent society’s norms by covertly seeking out mistresses.
2) Polygyny
Polygyny is the practice of one man marrying multiple wives. Wright explains that throughout history, societies with a highly uneven distribution of resources have favored polygyny, as elite men are able to support multiple wives and have a reproductive incentive to mate with multiple partners. Historically, this arrangement has been found in feudal, aristocratic, and monarchist societies with an extreme disparity between the social classes.
Polygyny provides a reproductive advantage to high-status men, who can then father far more children than if they had limited themselves to one wife. Wright argues that women may also have a reproductive advantage in polygynous societies, because if a society is stratified enough, the women may have more resources for their offspring by sharing a high-status man with other women than by having all the resources of a low-status man to themselves. However, Wright explains that this arrangement puts low-status men at a reproductive disadvantage, as they’ll end up with no partners at all.
3) Polyandry
Wright explains that polyandry is the practice of one woman taking multiple husbands. Though rare, this marriage practice tends to emerge in societies where resources are extremely scarce. This is because if the resources a man provides are inadequate to raise a child, the woman has an incentive to take on additional partners and pool their contributions.
Part 3: Family Ties
In addition to shaping human reproductive behaviors, Wright explains, evolution has shaped human behavior toward members of their families. In this section, we’ll explore why humans make sacrifices for family members, why siblings compete, and why parents may prioritize one child over another.
Sacrificing for Immediate Family
Wright explains that evolution has created a powerful instinct to make sacrifices for family members, such as sharing food or spending time helping or instructing others. This includes not just sacrifices parents make for children, but also sacrifices made for parents, siblings, cousins, or even distant relatives. However, this poses a slight paradox: If evolution rewards those who maximize their own self-interest, what benefit is gained by helping a sibling, cousin, or aunt?
To understand this tendency, Wright argues that we must turn our attention from the reproductive success of the individual to the reproductive success of the gene. A gene that encourages someone to make sacrifices for members of their immediate family would still have a strong chance of spreading, simply because families share the same genes. Therefore, those who benefit from others’ self-sacrificing behavior will also be carrying the gene.
Wright explains that self-sacrificing behaviors change in direct proportion to the amount of shared genes. Someone will be more likely to make sacrifices for a member of their immediate family than a member of their extended family, such as a cousin or uncle. However, they’re still more likely to sacrifice for extended family members than for complete strangers.
Competition Between Siblings
Wright argues that evolution hasn’t shaped human families to be completely altruistic. Siblings have a strong evolutionary incentive to compete with each other for their parents’ attention. A child’s survival depends on attentive parents, so those who succeeded at monopolizing this resource survived at a higher rate and went on to spread their competitive genes as adults.
Wright explains that this also pits children’s interests against their parents’. Because all children will be equal carriers of their parents’ genes, parents have a strong incentive to get their children to share resources equally rather than compete with each other. Thus, parents the world over try to teach their kids to share—while children compete with their siblings instead.
Prioritizing One Child Over Another
Though all children equally carry their parents’ genes, Wright explains that parents may still have an incentive to prioritize one child over another. This is because a parent can maximize the chance of passing on their genes through their children by investing more resources in the child that has the greatest chance of successfully reproducing. Wright argues that this varies by gender, social status, and age.
High-status parents tend to invest more in their sons than their daughters, since as high-status men, they’ll be more likely to attract many partners and pass on their genes. However, low-status families tend to invest more into their daughters, as they have a higher chance of “marrying up” and passing along their parents’’ genes with greater resource security.
Part 4: Social Instincts
In addition to reproducing and caring for family, humans have evolved strong instincts that govern how they behave in society. In this section, we’ll explore friendship, social status, reputation, social norms, and self-deception.
Friendships and Exchange
Wright argues that evolution explains why people form close friendships and help those who are not their immediate relatives. Humans were more likely to pass on their genes if they cultivated alliances that shared resources. This is because sharing resources can be more than a zero sum trade. If one person has a surplus of grapes, then for them, the relative value of each extra grape is low because they already have so many. By exchanging their grapes with someone who has a surplus of meat, both parties gain more value than they lose, providing a powerful survival advantage to both.
In addition to exchanging goods, Wright explains that friends also exchange information. By passing on knowledge about where to find valuable things, or who’s been fighting or sleeping with whom, friendships enable people to mutually improve their chances of survival and reproduction.
Sensitivity to Unfair Treatment
According to Wright, humans have evolved a keen sensitivity to unfair treatment. This is because people sometimes take advantage of each other in relationships, and there’s an evolutionary benefit to doing so. If one person consistently gives food to another while the other fails to reciprocate, the recipient has a survival advantage over the giver because they have more to eat. Because of this, humans instinctually evaluate contributions to relationships to make sure they’re fair.
That being said, Wright argues that a person’s sense of fairness is heavily biased in their own favor. In other words, our awareness of “fair” and “unfair” relates to how we’re being treated, not our treatment of others—so it’s not as accurate as we might hope.
Pity and Gratitude
Wright explains that helping others seems altruistic, but it’s motivated by a feeling connected to evolutionary advantage: pity. When someone pities another person who’s in an unfortunate situation, they’re driven to help. The person they help then feels gratitude, which incentivizes them to “pay back” the help in some way. In other words, doing a favor for someone you pity puts them in your debt—helping others isn’t an altruistic act, but rather a long-term investment in a future reward.
Social Status
Wright argues that evolution has created a strong tendency to form hierarchies of social status, which are found across cultures and species. Status hierarchies emerge because of two fundamental drives, both of which provide a reproductive advantage.
The first is ambition, a drive for status within one’s group. This presents a reproductive advantage, as people with higher social status have more potential mates and reproduce at higher rates. In most societies, they also have more access to food and other resources useful in raising children. Wright explains that while both men and women have this drive, it’s stronger in men. This is because men have more to gain reproductively by increasing their social status, since their biology places fewer limitations on the number of children they can have.
The second drive is deference, the tendency to submit to those with higher status. Wright explains that deference may have provided a reproductive advantage to the submissive individual—it helped them avoid expending energy or sustaining injuries in unwinnable fights.
According to Wright, all human societies have some form of status hierarchy. However, what determines status varies dramatically between cultures—it could be hunting skill, artistic talent, wealth, or even humility and wisdom. The underlying psychological machinery remains the same: To gain respect, people pursue excellence in the domains their culture values.
Treating Others Based on Social Status
In addition to seeking social status for themselves, Wright explains that a sense of social hierarchy informs how people treat others and cultivate relationships. Humans are naturally programmed to seek out alliances with higher status individuals, due to their better access to resources and connections. An alliance with a higher status individual, then, can yield better rewards than an alliance with a person of low status.
Reputation
Wright explains that humans have evolved a keen concern for their reputation. Broadly defined, reputation is simply what other people think about someone. Having a positive reputation improves someone’s social status in a hierarchy and provides them with more opportunities for friendships, alliances, and romantic partners. As a result, humans devote substantial time and energy to maintaining and improving their reputations. In this section, we’ll explore how concern for reputation encourages people to adopt social norms and maintain a positive perception of themselves, even if it’s based on deceit.
Social Norms
According to Wright, the concern for reputation encourages humans to adapt to their society’s norms. Every group has shared expectations for appropriate behavior, beliefs, and dress. Those who meet those expectations are held in higher regard than those who fall short. So, humans have a strong reputational interest to learn their group’s norms and carefully act in alignment with them.
For example, consider someone who grows up in a strict religious community where people wear plain and modest clothing. To maintain their reputation in the group, they adopt this norm as well, placing greater emphasis on group membership than on wearing flashy or stylish clothes. Wright notes that these norms can vary widely from culture to culture, but the desire to follow norms and remain in good standing is universal.
Self-Perception
Wright asserts that humans strive not only to enhance their reputation among others, but to maintain a positive perception of themselves, even if it’s embellished or self-deceptive. This is because confidence provides value: Humans who believe in their usefulness advocate more vigorously for their social status and alliances, improving their reproductive potential. Thus, humans are not only hardwired to embellish their positive qualities and disguise their faults, but to believe their own deceptions and act accordingly.
Part 5: Implications
Wright argues that an evolutionary understanding of human behavior can transform how we think about ourselves and our world. He highlights two domains that stand to be impacted by this awareness: psychology and ethics.
Psychological Implications
Wright argues that an evolutionary understanding of the human mind will change how we understand psychology. Traditional psychology, influenced by Freud, maintains that problems such as insecurity and low-self esteem can be solved by looking inward and reflecting on our childhoods. On the other hand, Wright says these negative emotional states were designed by evolution to spur people into action. Your brain isn’t meant to make you happy, but to make you seek group belonging, social status, survival, and reproductive opportunities. Instead of trying to “solve” insecurity and low self-esteem, Wright argues that you should treat these as drives impelling you toward behaviors that will bring social belonging and personal fulfillment.
Ethical Implications
Wright asserts that an evolutionary perspective complicates our understanding of morality. The traditional perspective holds that moral systems are the product of divine authority, and that “goodness” entails behaving selflessly. Evolutionary psychology provides an alternate view by showing that human morals evolved through natural processes and that they developed to maximize an individual’s “selfish” survival rather than their “selfless” goodness. Therefore, it’s possible to read evolutionary psychology as a license to behave selfishly and dispense with morals altogether.
However, Wright rejects this understanding, arguing that a perspective grounded in evolutionary psychology has the potential to make us more ethical, not less. He cites two ways it can do so: by making us skeptical of our own motives and more compassionate toward others’ failings.
Be Skeptical of Your Motives
Wright argues that an evolutionary perspective can make you more moral by helping you be skeptical about your motivations. He argues that people often overlook the ways that they’re behaving selfishly when they’re convinced that they’re doing something righteous. However, evolutionary psychology teaches us that our minds are designed to trick us into maintaining a positive impression of ourselves, no matter what we do. By keeping this perspective in mind, you can think critically about your motivations and better realize when you’re acting out of selfish evolutionary instincts.
Wright also cautions that just because a behavior is “instinctive” or shaped by evolution doesn’t necessarily mean that it’s “good.” Recall that our evolved psychological traits were shaped in ancestral environments very different from today’s world. This mismatch can lead to behaviors that made evolutionary sense historically but may be counterproductive now. For example, while a man’s attraction to multiple partners may have provided a reproductive advantage in hunter-gatherer societies, that doesn’t mean that it can’t have a destructive impact on family arrangements that provide stable environments for children.
Furthermore, Wright argues that even if a behavior provides a reproductive advantage, that doesn’t make it morally acceptable. For example, a fertility doctor who defrauds his patients and substitutes his own sperm for that of the intended father may produce more offspring, but that doesn’t make his deception OK.
Be Compassionate Toward Others’ Failings
Finally, Wright also argues that an evolutionary perspective can make us more compassionate toward others’ failings. Since people’s behaviors are largely determined by instinct, they don’t have nearly as much control over their actions as we might assume. By recognizing that others’ moral failings are the product of widely shared instincts that they didn’t choose, you can more easily view their failings with compassion instead of blame, knowing that their misdeeds aren’t entirely their fault.
