Franciscus Bernardus Maria (Frans) de Waal

1. Introduction

Frans de Waal (1948–2024) was a Dutch-born primatologist and ethologist whose work became central to late‑20th‑ and early‑21st‑century debates about human nature, morality, and animal minds. Trained as a biologist but widely read in philosophy, psychology, and anthropology, he argued that many capacities often treated as uniquely human—empathy, fairness, reconciliation, cultural learning—have clear precursors in other animals, especially primates.

De Waal’s research combined long-term observational studies of chimpanzees, bonobos, and macaques with controlled experiments on cooperation, inequity aversion, and prosocial behavior. On the basis of this work, he developed a continuity thesis: humans and other animals differ in degree rather than in kind with respect to many cognitive and moral capacities. He described these as moral building blocks on which explicit human ethical systems are later constructed.

His popular and scholarly books, such as Peacemaking Among Primates, Good Natured, The Age of Empathy, and Are We Smart Enough to Know How Smart Animals Are?, made empirical findings in primatology directly relevant to moral philosophy, philosophy of mind, and animal ethics. De Waal’s notion of anthropodenial—the refusal to attribute mental continuity where evidence supports it—challenged long-standing human exceptionalist assumptions.

While many philosophers and scientists drew on his work to support evolutionary ethics, moral sentimentalism, and expanded moral concern for animals, others questioned the interpretation of animal behavior as “proto-moral” and debated how far human–animal continuity should be taken. The following sections examine his life, intellectual development, principal works, central ideas, methods, and the broader discussions they provoked.

2. Life and Historical Context

2.1 Biographical Outline

Frans de Waal was born on 29 October 1948 in ’s‑Hertogenbosch, North Brabant, in the Netherlands. He studied biology at Radboud University Nijmegen and completed his PhD at Utrecht University in 1977 with a dissertation on aggression in macaques. Early research at the Arnhem Zoo in the Netherlands focused on chimpanzee social life, especially conflict and reconciliation.

In the early 1980s he moved to the United States, joining research centers associated with the Wisconsin National Primate Research Center and later Emory University in Atlanta, where he became a leading figure at the Yerkes National Primate Research Center. He remained professionally active until shortly before his death on 14 March 2024 in Atlanta, reportedly from cancer.

2.2 Historical and Scientific Context

De Waal’s career unfolded amid several broader shifts:

He worked within and against traditions shaped by Konrad Lorenz and Nikolaas Tinbergen in European ethology, as well as by American comparative psychology and behavioral ecology. These overlapping contexts positioned him as a bridge between biological research and interdisciplinary discussions about morality, consciousness, and culture.

3. Intellectual Development

3.1 Early Ethological Formation

De Waal’s intellectual trajectory began within European ethology, emphasizing naturalistic observation and evolutionary function. His doctoral work on aggression in macaques led him to view dominance hierarchies not simply as expressions of raw competition but as components of complex social regulation. This orientation predisposed him to interpret animal societies in relational and strategic terms, rather than purely instinctual ones.

3.2 Turn to Conflict Resolution and Social Repair

Work at Arnhem Zoo in the late 1970s and 1980s shifted his focus from aggression to post‑conflict behavior. Observing chimpanzees engaging in reconciliatory grooming and embraces, he framed such patterns as mechanisms of social repair. This phase crystallized the idea that primates manage relationships in ways that resemble norm‑guided behavior, a theme he later connected explicitly to the foundations of morality.

3.3 Evolutionary Roots of Morality

In the 1990s de Waal broadened his agenda from primate social dynamics to evolutionary moral psychology. Synthesizing observational data and emerging cognitive research, he proposed that empathy, reciprocity, and fairness constitute “moral building blocks.” Philosophers and psychologists began to engage his work as an empirical counterpart to sentimentalist and virtue‑ethical theories.

3.4 Expansion to Empathy, Culture, and Cognition

From the 2000s onward, his interests diversified: experimental studies of inequity aversion and prosocial behavior; arguments for animal culture and social learning; and critiques of human‑centered measures of intelligence. These developments reinforced his continuity thesis and led him to coin “anthropodenial” as a label for systematic under‑attribution of mental states to animals.

3.5 Late Engagements: Religion, Human Exceptionalism, Gender

In later years, de Waal addressed broader philosophical and social topics—religion’s relation to morality, the nature of intelligence, and gender differences—always through primatological evidence. This final phase integrated his earlier findings into explicit arguments about human society, normativity, and identity.

4. Major Works

This section surveys de Waal’s best‑known books, focusing on their central themes and scholarly significance.

These works collectively advanced de Waal’s continuity thesis while engaging audiences across biology, philosophy, psychology, and the broader public.

5. Core Ideas and Theoretical Framework

5.1 Moral Building Blocks and Evolutionary Continuity

At the center of de Waal’s framework is the claim that human morality rests on moral building blocks observable in other animals. These include:

• Empathy and emotional contagion
• Reciprocity and mutual aid
• Conflict resolution and reconciliation
• Inequity aversion and sensitivity to fairness

He proposed that such capacities evolved to stabilize group living and that human moral systems elaborate them into explicit norms, institutions, and justifications.

5.2 The Continuity Thesis and Anthropodenial

De Waal’s continuity thesis holds that differences between human and non-human minds are largely of degree. He criticized both naive anthropomorphism and what he labeled anthropodenial—a systematic refusal to recognize continuity where evidence supports it. In his view, comparative research should begin from evolutionary relatedness and then specify divergences, rather than assume human uniqueness by default.

5.3 Multi‑Level Model of Morality

De Waal outlined a layered picture of morality:

He argued that non-human animals mainly occupy the first two, perhaps three, levels, while humans add the fourth through symbolic cognition and culture.

5.4 View of Reason and Emotion

Contrary to rationalist accounts that prioritize detached deliberation, de Waal regarded emotions—particularly empathy—as primary in moral life, with reason as a later, organizing and sometimes self‑serving layer. He nonetheless acknowledged that reflective reasoning shapes institutional norms and extends moral concern beyond immediate circles.

6. Methodology and Empirical Approach

6.1 Ethological Foundations

De Waal’s methodology stems from classical ethology: detailed observation of animals in semi‑natural or social group settings, combined with evolutionary interpretation. He emphasized long‑term fieldwork and zoo‑based studies where individuals and social histories could be tracked over years.

6.2 Naturalistic Observation and Quantitative Coding

He systematically recorded behaviors such as aggression, grooming, and post‑conflict contact, later coding them quantitatively. In his reconciliation research, for example, he compared the frequency of affiliative contact in post‑conflict periods with matched control periods, interpreting elevated rates as evidence of deliberate social repair.

6.3 Experimental Paradigms

From the 1990s onward, de Waal increasingly used controlled experiments, often in captive primate colonies:

These experiments were typically embedded in familiar social settings, reflecting his concern that cognition be studied in ecologically valid contexts.

6.4 Comparative and Cross‑Species Approach

He employed a comparative method, examining similar behaviors across species (e.g., chimpanzees vs. bonobos; primates vs. other mammals) to infer evolutionary patterns. This approach sought convergent evidence for empathy, fairness, and cultural transmission.

6.5 Interdisciplinary Integration

De Waal drew on psychology, neuroscience, game theory, and philosophy to interpret data, while insisting that laboratory tasks remain sensitive to species‑specific abilities. Critics sometimes viewed his interpretations as theory‑laden, but supporters considered this integration essential for connecting behavior to broader questions about morality and mind.

7. Contributions to Moral Psychology and Ethics

7.1 Empathy as Moral Foundation

De Waal’s empirical work on empathy—ranging from emotional contagion to targeted helping—has been widely used in moral psychology. He argued that the capacity to share and respond to others’ emotional states is evolutionarily ancient and underlies both care for kin and broader prosociality. This has been cited in support of sentimentalist and care‑based ethical theories that foreground emotion in moral judgment.

7.2 Fairness, Reciprocity, and Inequity Aversion

Experiments demonstrating inequity aversion and cooperation in primates contributed to debates about the origins of fairness norms. Proponents interpret these findings as evidence that concerns about just distribution and balanced exchange are not purely cultural constructs but have deep evolutionary roots, informing discussions of distributive justice and social contract theories.

7.3 Proto‑Moral Agency and Moral Patients

De Waal’s notion of “moral building blocks” raised questions about whether some animals might be considered proto‑moral agents, not only moral patients. Ethicists have used his work both to argue for expanded moral consideration of animals and to reconsider the criteria for agency, responsibility, and blame.

7.4 Challenge to Rationalist and Contractarian Models

By emphasizing social emotions and pre‑reflective tendencies, de Waal’s work has been used to question ethical approaches that treat morality as emerging primarily from rational agreement or impartial rules. Some political theorists have drawn on his findings to support views of cooperation grounded in empathy and social bonds rather than exclusively in self‑interest or abstract principles.

7.5 Naturalistic Accounts of Moral Development

His multi‑level model of morality offers a naturalistic framework for moral development: early emotional and relational capacities provide the substrate on which cultural norms and explicit ethical theories are built. Psychologists and philosophers of development have engaged these ideas alongside work on child empathy, prosocial behavior, and norm acquisition.

8. Impact on Philosophy of Mind and Animal Cognition

8.1 Reframing Animal Intelligence

In Are We Smart Enough to Know How Smart Animals Are?, de Waal argued that cognition must be studied through species‑appropriate tasks. This view has informed philosophical critiques of intelligence hierarchies that rank animals along a single human‑based scale. Philosophers of mind have cited his work when arguing for pluralistic conceptions of intelligence.

8.2 Continuity of Consciousness and Self‑Awareness

De Waal’s observations of problem‑solving, perspective‑taking, and mirror self‑recognition in primates contributed to debates about consciousness and self‑awareness. Proponents use his findings to question sharp divides between human persons and non‑human animals, while some critics maintain that behavioral evidence underdetermines claims about subjective experience.

8.3 Anthropomorphism, Anthropodenial, and Comparative Method

His concept of anthropodenial has been influential in philosophical discussions of methodology in animal cognition. It has been contrasted with concerns about anthropomorphism:

De Waal urged a balanced approach that takes evolutionary relatedness and behavioral complexity seriously without abandoning methodological caution.

8.4 Normativity and Rule‑Following

Accounts of normativity often invoke uniquely human capacities for rule‑following and justification. De Waal’s descriptions of social expectations, policing, and reconciliation in primate groups have been used by some philosophers to suggest a spectrum of proto‑normative behavior. Others argue that without language‑based justification, such behaviors should not be labeled normative in the full sense.

8.5 Personhood and Moral Status

By documenting sophisticated cognition and social complexity in great apes, his work has informed philosophical discussions about personhood and the moral status of non‑human animals, including debates over great ape rights, captivity, and research ethics.

9. Engagement with Religion, Culture, and Gender

9.1 Morality and Religion

In The Bonobo and the Atheist, de Waal explicitly addressed the relationship between morality and religion. He proposed that moral behavior arises from evolved social instincts and group dynamics, with organized religions later codifying and reinforcing pre‑existing moral tendencies. Religious ethicists and philosophers of religion have variously interpreted this as compatible with, complementary to, or undermining of the view that morality is grounded in divine command or revelation.

9.2 Culture and Tradition in Animals

Through works like The Ape and the Sushi Master, de Waal argued that non-human primates exhibit cultural traditions, such as socially learned foraging techniques and social customs. He used cross‑group comparisons to support this claim. Anthropologists and philosophers of culture have debated whether such patterns merit the label “culture” or whether human culture is distinguished by symbolic representation and normative discourse.

9.3 Gender, Sex Differences, and Social Roles

In Different: Gender Through the Eyes of a Primatologist, de Waal examined sex differences and gender roles in primates and humans. He discussed patterns of aggression, caregiving, and dominance, and argued that both biological predispositions and social contexts shape gendered behavior. Some feminist theorists view his synthesis as supporting nuanced interactionist accounts; others question the extrapolation from primate data to human gender systems, especially where complex institutions and symbolic structures are involved.

9.4 Secular Humanism and Ethical Outlook

De Waal’s emphasis on empathy, fairness, and cooperation as products of evolution has been associated by commentators with forms of secular humanism. Yet he framed his views primarily in descriptive rather than prescriptive terms, focusing on how moral capacities arise rather than offering a complete ethical doctrine. Debates continue over how his naturalistic account relates to religious ethics and to secular moral philosophies grounded in autonomy, utility, or virtue.

10. Criticisms and Debates

10.1 Interpretation of Animal Behavior as Moral

A central debate concerns whether de Waal over‑interpreted animal behavior as proto‑moral. Critics argue that reconciliation, empathy‑like responses, or aversion to unequal rewards can be explained by conditioning, self‑interest, or dominance strategies without invoking morality. Proponents maintain that the complexity and flexibility of such behaviors, especially in socially rich contexts, justify viewing them as evolutionary precursors to moral concern.

10.2 Emotion vs. Reason in Morality

De Waal’s emphasis on emotional foundations has been challenged by philosophers who stress rational deliberation, impartiality, or rule‑following as defining features of morality. Some contend that his account cannot fully explain duties to distant others, impartial justice, or rights. Supporters respond that reason may extend and refine moral concern but still depends on underlying emotional capacities.

10.3 Human Exceptionalism and Continuity

The continuity thesis has sparked debate about the uniqueness of human language, normativity, and culture. Some philosophers argue that the step from proto‑norms to explicit rule‑governed practices is discontinuous and qualitatively distinct. De Waal’s defenders reply that sharp boundaries are empirically unsupported and that acknowledging degrees of continuity does not deny human distinctiveness.

10.4 Methodological Concerns

Methodologists in animal cognition have raised questions about experiment design and interpretive frameworks in de Waal’s work. Issues include small sample sizes, captivity effects, and anthropomorphic bias in coding behavior. Others counter that his combination of long‑term observation with targeted experiments provides unusually rich ecological validity, even if some studies remain hard to replicate.

10.5 Implications for Ethics and Religion

Religious thinkers sometimes object that his claim that morality predates religion reduces religious ethics to mere social reinforcement. Meanwhile, some secular ethicists worry that grounding morality in evolution risks naturalistic fallacies or relativism. These debates center on how, or whether, descriptive accounts of moral origins should shape normative ethical and theological claims.

11. Legacy and Historical Significance

11.1 Integration of Primatology and Philosophy

De Waal is widely regarded as a pivotal figure in bringing primatology into core discussions of moral philosophy, philosophy of mind, and animal ethics. His work helped establish animal behavior research as a legitimate source of evidence for theories of morality and cognition, influencing both empirical and conceptual scholarship.

11.2 Influence Across Disciplines

His writings have been cited across biology, psychology, anthropology, philosophy, theology, and legal theory. The concepts of moral building blocks, anthropodenial, and multi‑level moral evolution have become reference points in debates about human nature, cooperation, and the scope of moral community.

11.3 Shaping Public Understandings of Animals

Through accessible books and media appearances, de Waal significantly shaped public perceptions of animals as emotionally and cognitively complex beings. This has intersected with changing attitudes toward zoos, animal research, and welfare policy, even when specific policy implications remain contested.

11.4 Position in the History of Ideas

Historians of science and philosophy situate de Waal within a longer trajectory that includes Charles Darwin’s work on animal emotions and subsequent ethology. He is often seen as part of a late‑20th‑century reassessment of human exceptionalism, alongside developments in cognitive science and animal ethics.

11.5 Continuing Research Agendas

Ongoing studies in animal empathy, culture, and fairness frequently build on or react to de Waal’s findings. Future research on moral psychology, comparative cognition, and the evolution of normativity is likely to continue engaging with his models—either by extending them, refining them, or proposing alternatives. In this sense, his work remains a major point of reference for discussions about how morality and mind emerge from social and evolutionary processes.