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The power of moral conviction: How it catalyzes dogmatism, intolerance, and violence
Abstract
Our moral sense is a biological adaptation specific to our species. It has evolved to facilitate group living, regulate social interactions, and promote cooperation beyond kinship. Beliefs intensely associated with moral values can motivate positive societal progress. However, moral convictions can also lead to dogmatism, antagonistic attitudes, a polarized political climate, and violent collective actions. This article draws on theories and empirical evidence from anthropology, neuroscience, cognitive science, social psychology, economics, and political science to explain why and how moralization increases the strength of beliefs and attitudes –in certainty and importance. Moral convictions are perceived as absolute, universal, and definite beliefs or principles. They engage the brain circuit associated with reward processing and valuation, which motivates and reinforces behavior. Moral commitments act as signals to conform to the rules of one’s coalition, which causes predictable cognitive biases that benefit the self and the group. Moral convictions are held with great confidence. This leads to confirmation bias, which means that people are unwilling to seek or accept corrective information no matter how accurate the content of their beliefs. Once an issue is moralized, it becomes more challenging to engage in a cost-benefit analysis. A deeper understanding of attitudes, values, and moralization dynamics may allow social scientists and policymakers to identify and support pathways away from extremism and to strengthen and sustain engagement in benevolent forms of collective action.

Introduction

Do we respond similarly to news of petty crimes, police brutality, insurrection on the US Capitol, discriminatory social policies, or terrorist attacks? Some of these events betray basic values and principles, such as people's inherent worth and equality, respect for human rights, the importance of civil society, and the rule of law. This is the case because humans are a judgmental bunch. Cross-culturally, since the dawn of humanity, people judge some behaviors are right or wrong and deserving rewards or punishments. Perceptions of morality are increasingly generalized as people inhabit larger and more unfamiliar social networks and interact with anonymous persons (Jackson et al., 2024). Moreover, and contrary to what many people believe, morality (kindness, civility, honesty, and basic human decency) is not declining. It is just the opposite, as shown by a study spanning 60 nations worldwide (Mastroianni & Gilbert, 2023). On average, we treat each other far better than our forebears.

Converging lines of evidence–from game theory, biology, anthropology, psychology, and economics–suggest that morality is a collection of evolved adaptations for promoting group living and cooperation (Curry et al., 2019; Enke, 2019). As an ultrasocial species, humans highly value teamwork and cooperation, and our collective orientation benefits us individually by helping gain coalition partners, mates, and friends. The constellation of thoughts and feelings that constitute a sense of morality has evolved to enable individuals to uphold cooperative social relations that maximize their biological benefits (Krebs, 2008). However, while the capacity for morality is universal, there is tremendous variability in which behaviors people think are immoral. Despite substantial individual and cultural variation, nearly all manifestations of morality involve, are based on, influence, and govern our relations with other people (Rai & Fiske, 2011). Furthermore, morality has evolved as a natural extension of our coalitional psychology (Tooby, 2017). As a result, it is strategically tuned to specific aspects of group dynamics. This cultural-evolutionary account explains why morality can lead to dogmatism, intolerance, and violence.

What people believe to be of moral value has a huge impact on society, especially by motivating participation in collective action (cooperative effort towards group status improvement) and inspiring the courage to oppose injustices despite personal cost. Many positive societal changes, such as the struggle to obtain the right to vote for women in the United States in the 1920s, the civil rights movement in the 1950s, and the legalization of abortion in the 1970s around many countries, were the result of people holding strong moral convictions and their tireless engagement in a collective effort.

At the same time, moral convictions can facilitate hostile, inflexible, and at times violent actions, ranging from the cancellation of a book launch 1 to inter-ethnic riots that leave scores of people dead.  For better or for worse, moral convictions trigger more ardent reactions than other attitudes and beliefs. The extent to which a person considers a given topic (e.g., mining, the use of glyphosate, illegal immigration or the commercial use of body parts to take a few examples) to be within the scope of moral beliefs that are perceived as transcending the boundaries of persons, cultures, and contexts has wide-ranging and a variety of predicted negative interpersonal outcomes. These include dogmatism, intolerance of those who do not share the same views, unwillingness to compromise or accept procedural solutions to conflicts with little space for economic gain, and a host of other potentially harmful consequences.

This dark side of morality is the focus of this essay. Given that strong moral convictions are likely to be associated with acceptance of any means to achieve preferred goals (Skitka, 2010), a better understanding of whyattitudes rooted in morality can promote disruptive forms of social engagement constitutes an important endeavor for interdisciplinary research with consequences to public policy.

In this article, I adopt a naturalistic perspective 2, integrating empirical evidence and theories from multiple disciplines. Social phenomena like morality can be more comprehensively and accurately understood if their explanations maintain consistency and coherence across different levels of analysis. A vertical integration of knowledge across the biological sciences and the social sciences requires an effort to make them coherent and consistent (Cosmides, Tooby & Barkow, 1992). A biological perspective can inform social systems and provide a comprehensive understanding of social phenomena. Observations, knowledge, and concepts of higher and lower levels of analysis can mutually inform and calibrate those of other levels. Moreover, because of the emergent properties of complex organizations, it is unlikely that an understanding of higher-level psychological processes can be satisfactorily derived from neurophysiology alone (Berntson et al., 2012). Nor, for that matter, by a restricted analysis of any single level of organization or function, whether it be sociological, psychological, or neurobiological. Thus, these differing perspectives need to be integrated.

This article develops an integrative analysis of the empirical and theoretical literature based on a selection of articles from the social sciences and the biological sciences (Figure 1), to explain why and how the moralization process increases the strength of beliefs and attitudes - in certainty and importance - which, in turn, motivates social commitment and induces dogmatism and attitudinal extremism at the individual level, regardless of ideological or political affiliation.

Figure 1: This integrative analysis includes 278 articles (67% published in the last decade) in anthropology, biology, neuroscience, psychology (developmental, cognitive & social), sociology, economics, and political science to explain why and how the moralization process increases the strength of beliefs and attitudes - in certainty and importance - which, in turn, motivates social commitment and induces dogmatism and attitudinal extremism at the individual level, regardless of ideological or political affiliation.

Figure 1: This integrative analysis includes 278 articles (67% published in the last decade) in anthropology, biology, neuroscience, psychology (developmental, cognitive & social), sociology, economics, and political science to explain why and how the moralization process increases the strength of beliefs and attitudes - in certainty and importance - which, in turn, motivates social commitment and induces dogmatism and attitudinal extremism at the individual level, regardless of ideological or political affiliation.

The article is organized into eleven sections. Following this general introduction, the second section explains why studying moral conviction matters. The third section presents a functionalist perspective on morality as it is currently described in evolutionary anthropology and psychology (developmental, cognitive, and social), followed by a section on the social domain theory of morality. The fifth section focuses on virtuous violence. The interwoven nature of morality and group dynamics, which stems from the selective pressures inherent in the evolution of our species is the subject of the sixth section. The cognitive architecture of moral convictions is outlined in the seventh section, followed by a section describing the moralization process and its neural mechanisms. Mental rigidity, a sense of superiority, and high subjective confidence are frequently associated with moral convictions. This class of phenomena, grouped under the umbrella term of metacognition, is the subject of the ninth. A final section before a general conclusion briefly addresses strategies to counter moralization. A glossary of the terms and key concepts used in the paper (e.g. coalition, reward system, social influence, valuation) is provided before the list of references.

Overall, the understanding that emerges from integrating social sciences and biological science knowledge, demonstrates that moralization strongly increases the strength of attitudes ­–their certainty and importance– which in turn motivate political commitment, dogmatism, and ideological extremism, independent of the political sophistication of the actors and across the political spectrum. Moral conviction is the catalyst that turns beliefs into action, for better and for worse.

Why studying moral conviction matters

Moral convictions can inspire change and positive collective action but can also prompt dogmatism, intolerance, and societal divisions. Every day, we are bombarded with news reports of protests related to conflicts associated with social values. Some of them are extremely violent and result in the loss of human lives. As a dramatic example, in November 2002 in the city of Kaduna, Nigeria, around 250 people were killed in a series of religiously-motivated riots. The apparent trigger for the violence, which became known as the "Miss World riots," was an article published in a Lagos-based newspaper that was perceived as blasphemous by some Muslims. Within days, expressions of displeasure or offense at the article were seized upon by some militant groups, and the protests turned violent. Muslims attacked Christians and Christians retaliated against Muslims. Both groups went on a rampage, killing, burning, and looting. Not lethally violent, yet still concerning, decades ago, following the publication of Thornhill and Palmer’s academic book on “A natural history of rape –biological bases of sexual coercion,” which offered a different view on rape contrary to social constructivism that considers it an expression of male domination without sexual arousal, Joan Roughgarden vehemently responded in the journal Ethology (2004), arguing that “critics of evolutionary and human-sexuality psychology should realize that they're dealing with a political fight more than an academic dispute. We must organize as activists to oppose this junk and get out of our safe comfortable armchairs, for much is at stake. Thornhill and Palmer are guilty of all allegations, and they deserve to hang.”3

Moralization can therefore inspire benevolent forms of collective action like the American civil right movement, but it can also incite dogmatism, intolerance, division, authoritarianism and harmful consequences (i.e., aggressive attitudes, justification of prejudice, vigilantism, and political violence) against people or groups who share different values or practices (Yoder & Decety, 2022).4 All are serious threats to personal autonomy, civil liberties and political rights. In the United States as well as a growing number of countries, liberals and conservatives are often incapable of reaching policy agreements on polarized social issues, from gun control to economic policy to health care and climate change. This partly stems from divides in fundamental values (Marie, Altay & Strickland, 2023). In August 2023, the number of Americans who believe the use of force is justified to restore Trump to the White House increased by roughly 6 million in the last few months to an estimated 18 million people, according to a survey conducted by the University of Chicago Project on Security and Threats.

Moralization frequently occurs in the public domain (e.g., about smoking, sexually transmitted diseases, vaccinations). It can be a positive force by signaling that an issue is morally important, and lead to good outcomes, but it can backfire and lead to psychological reactance, a motivational state of resistance, and bring about the opposite effect of the intended behavioral change (Kraaijeveld & Jamrozik, 2022). For instance, moralization of public health issues can legitimize stigmatization, ostracism and political division with counterproductive outcomes. In one study, female subjects were exposed to a stigmatizing versus non-stigmatizing health message with forceful versus non-forceful wording (Schnepper, Blechert & Stok, 2022). Then, the effects on a virtual food choice task (healthy versus unhealthy), diet intentions and concerns to be stigmatized were measured. The results indicate that in the non-stigmatizing and non-forceful condition, participants made the highest number of healthy food choices. Conversely, in the two stigma conditions, higher body mass index correlated with higher concern to be stigmatized, highlighting the adverse effect a health message can have. Opiates were not moralized in the past century, and morphine was a respectable medical treatment for alcohol addiction (Siegel, 1986. Today, the use of opiates is moralized and criminalized, and yet according to the National Center for Health Statistics over 106,699 drug-involved deaths (mostly opioids) were reported in 2021 in the US.

It is, therefore, important to understand the motivations, psychological mechanisms, and social variable that underlie and predict why and when moralizing can be dangerous. This knowledge is valuable in finding ways to facilitate tolerance between individuals, to encourage openness to alternative points of view, to reduce dogmatism, and to avoid legislative gridlocks. For example, the propensity in the United States to moralize attitudes on a variety of issues such as social justice, illegal immigration, vaccination, health care coverage, income inequality, or gender equality predicts greater social distance as well as prejudice, anger, incivility, and antagonism toward supporters who hold opposing beliefs (Garrett & Bankert, 2020). This polarization, which is largely affective, is not the direct cause of political violence. But it does help create an environment that allows opinion leaders to increase violence against politicians, election officials, women, and many types of minorities. It fosters an anti-establishment sentiment with a distrust of institutions and science. An editorial published in Science, one of the world’s top academic journals, by a group of psychologists and sociologists sounded the alarm about political bigotry in the United States, calling it a poisonous cocktail of alienation, aversion, and moralizing that poses a serious threat to democracy (Finkel et al., 2020).

While morality binds us to others, allowing for more harmonious cooperation and coordination–undoubtedly essential foundations of our civilization, it can also blind us to distrust and demonize those who do not think, behave, or agree with us. At times, morality can motivate and justify intolerance and violence. Some people commit acts of violence because they sincerely believe that it is the morally right thing to do. In the minds of many perpetrators, violence can be a morally necessary and appropriate way to regulate social relationships according to precepts and cultural prototypes. These moral motivations apply equally to violent heroes of the Iliad as they do to contemporary environmental activists who destroy agricultural crops in opposition to genetically modified organisms, death threats against two Australian philosophers who suggested in an academic paper that newborns and fetuses are morally equivalent ''potential persons'' whose family's interests override theirs, rioters of religious and ethnic rights through India and Africa, or parents who use corporal punishment to discipline their children.

Dogmatism, intolerance, and resulting physical, verbal, or symbolic violence motivated by moral conviction are thus serious concerns in today’s world. Moralized identification with one group/coalition leads to polarized attitudes, identity-based ideology (whether it’s gender, sexual orientation/identification, religion, race, ethnicity, or socioeconomic status), and sectarianism. The more individuals are certain of a belief –regardless of its objective correctness—the more durable it will be, and the more willing they are to express their opinion and shun others who do not accept their views (Tormala & Rucker, 2015), and polarize the political debate. Social media, currently used by 5 billion people, amplifies polarizing and divisive messages, especially for moralized content (Rathje et al., 2021). Such a combination is potentially toxic and undermines our democracies, as well as our capacity to harmoniously live together and find pragmatic solutions to current challenges. It seems rational to strongly defend a view about facts that one evaluates as beyond doubt, like the earth is round or viruses evolved faster than any other living organisms. Distinguishing the epistemology of factual and normative beliefs is important to consider.

A functionalist perspective on morality

Moral thinking pervades our lives, and this is specific to our species. The human predisposition for social preferences5 and cooperation has emerged through natural selection in part due to the benefits it conferred on our ancestors living in large groups. This requires complex systems of social evaluation to distinguish individuals who can be trusted, who are likely to cooperate from those who are not. Our species has the propensity to produce cultural organizations that create social norms (regulation of acceptable and standard ways of behaving and achieving goals) and enforce them through institutions designed to assess the acceptability of individuals' behaviors and assign appropriate punishments to those who violate social norms (Tomasello, 2016).

A large body of literature in anthropology, psychology and economics indicates that our species has evolved interlocking sets of values, virtues, norms, practices, identities, institutions that work together to suppress or regulate self-interest and make cooperative societies possible (Haidt, 2011). These adaptations are thought to be the product of gene-culture coevolution (Bowles, 2016; Boyd, 2018; Gintis, 2011; Henrich, 2016). All human societies develop social norms and systems of social regulation, which owe their effectiveness to the ability of individuals to integrate, share, and respect them as much as have them respected by others. This enables stability in living together and promotes large-scale cooperation (Boyd, 2018). Morality regulates interpersonal exchange, facilitates survival, coexistence, and cooperation, minimizes aggression, and more generally provides a balance when individual interests conflict with collective interests (Curry et al., 2009). While it is true that many non-human animals collaborate with their own species, humans are exceptional in their social preferences. They help one another based not only on kinship and reciprocity (direct and indirect), but also on apparently unselfish motives driven by altruism, empathy, and benevolence. Humans seek means for all to benefit through enacting norms to promote and maintain fairness, equity, and justice within the community. Social preferences are associated with happiness and well-being (Iwasaki, 2023). Many studies have reported a correlation, and some have found a causal reciprocal relationship between behaving prosocially and happiness (Aknin & Whillans, 2021; Meier & Stutzer, 2008).

We are motivated by morality because it is advantageous at the individual level –a non-zero-sum game (Delton & Krasnow, 2015)6. These moral concerns are not located in an abstract world characterized by ivory tower speculation. We are inherently and deeply social animals. Nearly all manifestations of morality involve, build upon, influence, and often govern our relationships with others. The ability to think and act in accordance with moral norms is a hallmark of our species. Of course, we are not conscious of the ultimate explanation of behaviors (the why question), those concerned with fitness consequences.

A strong argument in favor of the evolutionary origins of morality comes from developmental research demonstrating that the foundational aspects of social evaluation and precursor of morality are present early in ontogeny, before input from socialization (Decety, Steinbeis & Cowell, 2021; Tomasello, 2014). Preverbal infants possess an innate system of social evaluation that is similar to what evolutionary biologists, anthropologists, and psychologists have posited to be required for the emergence of our species' sociability (Hamlin, 2013). They distinguish between positive and negative social interactions, positively evaluate those who cooperate and negatively evaluate those who do not, expect other people to prefer those who have helped versus hindered them, and consider mental states when evaluating others (Decety, 2019; Cowell & Decety, 2015; Hamlin, 2015; Ting et al., 2020). Before their second year, toddlers direct their own antisocial behaviors appropriately, selectively taking resources from someone who has previously hindered a third party (Hamlin, Wynn, Bloom, & Mahajan, 2011), and showing concern for issues of justice and fairness (Ting et al., 2020).

Children as young as 15 months perceive the difference between equal and unequal distribution of food, and their awareness of equal rations is linked to their willingness to share a toy (Schmidt & Sommerville, 2011). Subsequent studies with infants of the same age demonstrate that they use fairness concerns to guide their social selections (Burns & Sommerville). However, infants also take into consideration the race of individuals, and the consequences of the behavior of these individuals for their own- versus other-race individuals. When the distributor’s race (Caucasian vs. Asian) is pitted against prior fair behavior, infants no longer systematically select the fair distributor, suggesting that infants incorporate information about the individuals’ races when making social selection, and weigh race and fairness as competing dimensions in their social decision.

Ingroup favoritism – the tendency to favor members of one's own group over those of other groups emerges early. For instance, research indicates that 17-month-old infants possess an abstract expectation of ingroup support that already guides their reasoning about how individuals will act toward others (Jim & Baillargeon, 2017). When an individual needed help and another individual from the same minimal group was present, infants expected this second individual to support her ingroup member; no such expectation arose when the two individuals were not members of the same group. Infants around 14 months old begin to show cooperative behaviors, such as spontaneously and indiscriminately helping others (Warneken & Tomasello, 2007). This disposition is then influenced by judgments of likely reciprocity and their concern about how they will be evaluated by others (reputation) (Engelmann & Rapp, 2018). In costly sharing and prosocial tasks, when sharing incurs no cost, 5-year-olds treat kin and friends more favorably than strangers, while 6-year-olds favor kin over friends when sharing resources incurs a cost, showing kin favoritism (Lu & Chang, 2006).

In their second year, infants possess context sensitive-expectations relevant to fairness. They expect an experimenter to give a reward to each of the two individuals when both have worked to complete an assigned chore, but not when one has done all the work while the other was playing (Sloane et al., 2002). Across cultures, young children show a desire to appear fair in resource distribution and are more willing to distribute resources equitably with age, suggesting a universal increased preference for equity over equality throughout development (Huppert et al., 2019). A rudimentary understanding of the normative dimension of human actions can be observed in 18-month-old toddlers (Schmidt, Rackoczy & Tomasello, 2019). Normative behavior develops around 3 to 5 years of age, without explicit teaching. Young children of this age can distinguish prescriptive from descriptive social rules (Nucci, 2001; Smetana, 2013; Sripada & Stich, 2006). Around the same time, children express obligatory judgments based on moral concerns with others’ welfare, rights, and fairness through spontaneous reactions and reasoning about perceived violations, and begin to enforce social norms on others (Killen & Smetana, 2015).

Morality incorporates multiple dimensions, including sensitivity to social norms, values, reputation, and the set of capacities involved in reinforcement learning (including reward and punishment-based decision-making). It involves nonconscious and implicit processes such as an aversion to harming the vulnerable, concern for others, social emotions (e.g., guilt, shame, outrage, gratitude, and pride), as well as more conscious processes such as theory of mind and deliberative reasoning (Decety & Cowell, 2018; Van Bavel et al., 2015). Although moral values are personal in the sense that they are internalized, they are acquired in a social context and are shared with others from our social group (Schwartz, 2014). The mechanisms by which beliefs are conferred and become shared include the propagation of social norms about common goals and the establishment of moral principles or standards of conduct that should be followed.

Social groups play a key role in the establishment of prescriptive social norms. Importantly, decisions and behaviors that uphold moral values are perceived as highly rewarding (Bartels et al., 2015; Yoder & Decety, 2018). Moreover, judgments about moral norms are highly affected by social conformity. In keeping with the large body of work showing how decisions and behaviors are influenced by majority opinions, some studies have demonstrated that moral judgments are subject of conformity pressure. In one study, participants were asked to make decisions about sacrificial dilemmas either alone or in a group of confederates (Kundu & Cummins, 2013). Under social conformity, permissible actions were deemed less permissible and impermissible actions were judged more permissible. Another study found that while subjects do tend to conform to the majority opinion on moral matters, they do so in a selective manner by conforming more when the majority opinion is of a deontological nature than when it is of a consequentialist nature (Bostyn et al., 2017). This asymmetric conformism effect is theorized by the authors to be driven by strategic concerns related to mutualistic partner choice preferences.

Across studies in social psychology and cognitive neuroscience, it is well documented that the opinion of others modulates the reward and value systems. In particular, the magnitude of activity in the ventral striatum reflects the value of reward-predicting stimuli (Campbell-Meiklejohn et al., 2010). Social influence mediates very basic value signals in known reinforcement learning circuitry and explains the swift spread of values throughout a group of individuals. The reward circuit generates signals related to a broad spectrum of social functioning, including making decisions influenced by social factors, learning about other members of our communities, and following social norms (Bhanji & Delgado, 2013).

Morality is generally thought to be based on injunctive and descriptive norms about how people should behave toward each other (Killen & Smetana, 2015). Descriptive norms are simply regularities of behavior, what most people do in a given situation, while injunctive norms are behavioral expectations supported by social or material sanctions (Simpson & Willer, 2015). A substantial body of evidence shows that people conflate what is descriptively normal (common or frequent) with what is prescriptively normal (allowed or required), reflecting the common-is-moral association (Heyes, 2024). When 35,000 participants from 30 European countries were asked to evaluate the morality of questionable behaviors (e.g., cheating on tax declaration or having casual sex), there was a positive correlation between their ratings of the frequency and justifiability of the behavior (Eriksson et al., 2021). Injunctive norms have an effect. For instance, studies conducted among Christians-American have found that participants donated more money to charity (Malhotra, 2010) and watched less porn on Sundays (Edelman, 2009). However, they compensated on both accounts during the rest of the week. Likewise, a study conducted in Morocco found that whenever the Islamic call to prayer was publicly audible, local shopkeepers contributed more money to charity (Duhaime, 2015). However, these effects were short-lived. Donations increased only within a few minutes of each call and then dropped again.

Numerous other studies have yielded similar results. People become more generous in a donation task (Xygalatas et al., 2016) and cooperative in a bargaining game (Xygalatas, 2013) when they found themselves in a place of worship. Importantly, this effect is not due to intrinsic religiosity (the disposition) but an artifact of contextual cues (the situation).

In addition, one's own survival and success depend on trustworthy, competent, and motivated collaborative partners (Noë & Hammerstein, 1994). Thus, within a cultural group, individuals are concerned with how others evaluate them and invest energy to maintain the appearance of being fair and keep a good reputation (Caviola & Faulmüller, 2014). Conformity to the prevailing practices and social norms is vital to advertise group identity. It is plausible that morality is the product of cultural evolution over a potentially shorter period, by selecting cognitive and motivational mechanisms specialized for processing social norms (Heyes, 2024). Her cultural-evolutionary model proposes that norm psychology depends on implicit domain-general processes (perceptual, attentional, learning, motivation) that are genetically inherited as well as explicit domain-specific processes that are culturally inherited. Such capacities and practices have evolved over hundreds of thousands of years since humans first banded together for fitness and survival.

Moreover, some evolutionary anthropologists have argued that moral judgment is routinely strategic (DeScioli et al., 2014). Human societies have a variety of rules, and some benefit some people more than others. This panoply of moral rules with differential effects is part of the enduring social ecology of Homo sapiens, and natural selection has favored cognitive adaptations for advocating rules that enhance the individual’s fitness (Mercier, 2011). Group living has persistently constituted a fundamental aspect of our evolutionary history, and thus selection has favored psychological adaptations to enable and regulate behavior both within and between groups (Forgas et al., 2007).

Overall, morality has evolved as a regulatory system that includes the creation and sensitivity to social norms, notions of justice, fairness, and rights, and a meta-perception of some of our decisions, judgments, and attitudes that can vary in intensity. Overall social and moral norms facilitate a harmonious and cooperative co-existence, especially when individuals have a high degree of conformity.

Social domain theory of morality

Over decades of research in psychology, it has become clear that what people subjectively experience as moral is psychologically different from what they experience as social preferences or conventions. Across cultures and very early in development, people classify behaviors, values, beliefs, and practices into distinct categories (Smetana, 2013; Nucci, 1996; Turiel, 2006). The moral domain includes actions considered inherently wrong because of their detriments on the well-being of others, such as physical and psychological harm, violations of property, or damage to equity. The moral domain thus brings together prescriptive judgments of justice, rights, and welfare considerations relating to how people should treat each other. Moral judgments are impersonal, generalizable, and motivate the possibility of sanction to enforce respect for people and their rights. The conventional domain includes actions that are not inherently wrong but whose wrongfulness depends on the existence of a rule or norm (such as how to dress for a wedding or a funeral), and these rules and judgments of the conventional domain vary according to time and place. They are, therefore, not universal. Judgments that fall into this category are justified by reference to the maintenance of social norms and respect for authority. Finally, the personal domain encompasses preferences and actions whose consequences do not affect other people or society (the private sphere). Though people disagree about what falls into each of these three domains, once a belief, value, or practice has been categorized into one of them, the categorization consistently and powerfully predicts people’s responses to it, especially when it differs from their own (Wright, 2023). Overall, the wrongness of moral transgressions is seen as stemming from their intrinsic features, such as their intrusion on others’ rights and welfare (Smetana, 2013).  Morality is seen as normatively binding, and thus, moral rules are hypothesized to be unalterable. However, depending on the culture, moral principles may carry different weight, and the boundaries between domains are fuzzy. Depending on historical epochs, social ecology (population density, mobility, pathogen avoidance, weather), religious beliefs, and institutional rules (e.g., kinship structure and economic markets), each society develops a moral system that emphasizes specific orientations (Bentahila et al., 2021). Furthermore, there are cross-cultural differences in the tightness of social norms that impact the enforcement of moral rules and punishments (Gelfand et al., 2017).

Another theoretical perspective proposes that moral beliefs and attitudes are a matter of degree rather than just a matter of kind. The moral significance that people attach to different issues or problems varies according to historical time, culture, and geography (Skitka et al., 2021). Attitude toward smoking, for example, has evolved from a matter of preference to increasing moralization over the past 60 years. Similarly, there was a time when abortion was unrestricted by law in the United States, and abortion services were openly marketed. Abortion restrictions in the United States were not initially grounded on moral concerns, but were rather rooted in concerns about medical licensure and the desire of increasingly professionalized healthcare providers to stem competition from midwives and homeopaths (Reagan, 2022). Attitudes toward abortion vary widely across cultures (Ryan, 2014). Today, however, abortion has become a highly moralized and politically polarizing issue in the United States, mostly for white evangelical Christians. They consider abortion to be morally wrong, and argue that it should be illegal. However, relatively few Americans actually view the morality of abortion in stark terms. According to a 2022 Pew Research Center report, 7% of all U.S. adults say abortion is morally acceptable in all cases, and 13% say it is morally wrong in all cases. A third of them say that abortion is morally wrong in most cases, while about a quarter (24%) say it is morally acceptable most of the time. About an additional one in five do not even consider abortion a moral issue.

In this theoretical context, morality is not an essential characteristic of certain domains of decisions, choices, judgments, or attitudes. Rather, it is a meta-perception that people have of some of their decisions, beliefs, judgments, and attitudes, which can vary in strength. Morality is a matter of degree rather than a matter of kind.

The fact remains that our capacity for morality is universal. It must be understood by distinguishing a moral capacity and moral values: while our moral capacity is universal, the moral rules and values we develop are quite diverse. They vary according to times, places, cultures, history, and our choices. For example, bullfighting is considered a barbaric and immoral practice of animal torture in many countries where it is therefore prohibited, while it is perceived as a cultural heritage in Portugal, Spain, Venezuela, and southern France where it receives public subsidies. In 2020, same-sex relationships were punishable by law in 69 out of 193 countries and carry the death penalty in 11 countries. Currently, gay marriage is legal in 34 countries.

How do we reconcile the universality of our moral capacity and the plurality of our morals? Contrary to what is too often believed in social sciences, a naturalist perspective on morality is not necessarily reductive. It does not eliminate levels of organization. Rather it seeks conceptual unity and relations that cut across levels. Complex phenomena require accounts at multiple levels of organization. Different levels must be mutually compatible, but no one level reduces to another (Barkow, 1991). In fact, this perspective can help us understand our moral capacity's natural basis without limiting its diversity. Here, the usual dichotomy between nature and nurture is misleading and unnecessary. It is no longer defended by most evolutionary/cultural anthropologists. All humans possess an evolved ability to create, learn, and uphold moral rules and social norms and adapt them to new situations. Therefore, moral cognition is itself universal, whereas moral rules differ from group to group and within the same group over time.

Morality corresponds to a set of principles and norms that guide the conduct of individuals within their group. While some moral principles seem to transcend time and cultures, (e.g., fairness or family obligations), moral values are generally not set in stone. Almost all manifestations of morality involve, rely on, influence, and govern our relationships with others.

Virtuous violence

Violence is generally and wrongly considered as the antithesis of sociality. It is usually seen as an expression of our animalistic nature, which is expressed when learned cultural norms break down or when our ability to control and inhibit ourselves is deficient. Violence is also perceived as the essence of evil, the prototype of immorality. It manifests in many different ways such as a reflex behavior (reactive aggression), coercion, threat of physical force, hostility, and terror, and thus needs to be determined by assessing intentionality.  Studies in behavioral ecology and anthropology indicate that humans have a high potential for proactive aggression (involving some degree of premeditation) toward their fellow humans, including lethal violence, an attitude we share with other primates, and chimpanzees in particular (Gómez et al., 2016). Furthermore, this potential for violent aggression is much higher in men than in women, likely due to an unusually high benefit/cost ratio for intraspecific aggression in the former (Georgiev et al., 2014). Overall, human aggression is characterized as a combination of low propensities for reactive aggression and coercive behavior and high propensities for proactive aggression (especially coalitionary proactive aggression). These tendencies are associated with the evolution of groupishness, self-domestication, and social norms (Sarkar & Wrangham, 2023).

Most psychological theories of morality hold that at their core, moral judgments always include a prohibition against unprovoked killing, harming, stealing, and lying (Turiel, 2012; Gray et al., 2012). Support for violence can only be construed as a moral violation, an error in moral performance, or a necessary evil to achieve a greater good. Y