A Natural History of Human Thinking by M.Tomasello

Abstract

Ever since Darwin, thinkers have struggled to identify what differentiates human beings from other animals. Michael Tomasello argues that cooperative social interaction is the key to our cognitive uniqueness. Once our ancestors learned to put their heads together with others to pursue shared goals, humankind was on an evolutionary path all its own.

Context

Michael Tomasello (b. 1950) is an American developmental and comparative psychologist at Duke University, USA. He has led pioneering research on the origins of social cognition, leading to new insights into both developmental psychology and primate cognition. Tomasello argues that human uniqueness is the capacity to share attention and collective intentionality, an evolutionary novelty that has emerged as a cooperative integration of apes' skills that formerly worked in competition. Harvard University Press published Tomasello’s A Natural History of Human Thinking in 2014.

In his paper Précis of A Natural History of Human Thinking (2015), Tomasello explains the background to his book:

"In 2001 I attended a workshop here in Leipzig (hosted by Georg Meggle) on Margaret Gilbert on social facts. Reading her work, I decided to present a paper on “Can chimpanzees take a walk together?" The answer was, of course, that they cannot in the relevant sense; that is, they cannot make a joint commitment to take a walk together. And this provided a new way of looking at things...The new ape data suggested that...one can understand others as intentional agents for purposes of competing with them. So the answer must be that only humans both understand others as intentional agents and have the skills and motivations to share intentional states with them."

He also argued that:

"...indeed what most clearly distinguishes humans from other great apes, from a psychological point of view, is that humans operate with skills and motivations of shared intentionality."

Tomasello adapted the conceptual vocabulary of several philosophical accounts of normativity, collective intentionality and the social construction of mind and connected them to his empirical findings to develop his theory.

Vygotsky

Lev Vygotsky’s claim that higher mental functions develop through social interaction, summed up in his idea that “learning leads development” in Thought and Language (1934), is echoed throughout Tomasello’s A Natural History of Human Thinking (2014). Tomasello argues that children’s cognitive capacities (concepts, norms, reasoning) emerge in cooperative activities and pedagogical encounters: social learning doesn’t merely transmit skills but restructures individual cognition, mirroring Vygotsky’s emphasis on the social origin of higher cognition.

Vygotsky wrote that learning happens first on the social plane and then on the individual plane, and Tomasello directly operationalises this in his account of shared intentionality. Tomasello shows how joint attention, joint goals, and communicative teaching create the social contexts in which children internalise cultural practices and develop new cognitive forms, precisely the process Vygotsky described when he explained how social interactions become internalised mental functions.

Vygotsky’s notion of the Zone of Proximal Development (ZPD) — that children can perform more complex tasks with guidance than alone — resonates in Tomasello’s focus on pedagogy and guided participation. Tomasello emphasises natural pedagogy and adult scaffolding as mechanisms by which children are taught conventions and norms. These guided interactions accelerate cognitive change in ways that echo Vygotsky’s ZPD framework.

Vygotsky stressed the role of language as a primary tool of thought, famously noting that “tool and sign systems mediate mental functioning.” Tomasello extends this by showing how shared communicative signs and conventions become cognitive tools that transform thinking. Where Vygotsky provided a developmental theory linking social interaction, language, and higher cognition, Tomasello furnishes empirical, comparative, and evolutionary detail — demonstrating the specific social-cognitive mechanisms (shared intentionality, joint attention, and pedagogy) through which Vygotskian dynamics operate.

Ludwig Wittgenstein

In Philosophical Investigations (1953), Wittgenstein wrote, “Meaning is use." Tomasello adopts this notion by showing that children learn words and concepts through shared activities. In A Natural History of Human Thinking, Tomasello argues that meaning arises in joint attention and cooperative tasks, so words become tools for coordinating action rather than private mental labels.

Wittgenstein’s point that “following a rule is not a case of obeying a rule privately” appears in Tomasello’s account of normativity. Tomasello finds that children treat conventions as correct or incorrect according to communal standards: they expect others to conform and will enforce shared rules, demonstrating rule‑following as a social practice.

Wittgenstein insisted that a “private language” is incoherent, and Tomasello translates this into a developmental and evolutionary claim: human thinking is public and conventional because shared intentionality and teaching make meanings communal. Tomasello’s narrative turns Wittgenstein’s philosophical rejection of private meaning into an empirical story about how children become cultural participants.

Where Wittgenstein offered conceptual remarks — for example, that language belongs to a “form of life” — Tomasello supplies mechanisms and data. He tests how joint attention, pedagogy and social interaction create the very language games.

Raimo Tuomela

Collective Intentionality (1984) is Tuomela's seminal statement distinguishing collective vs. individual intentions. It introduces group modes and social ontology. Tuomela’s analysis of collective intentionality provided the conceptual scaffolding that allowed empirical researchers to identify and describe ‘we‑intentions’ in observable behaviour.

His we‑mode/I‑mode distinction clarified how group‑level commitments differ from mere aggregations of individual attitudes, a distinction Tomasello uses when interpreting children’s enforcement of social norms. Tuomela’s account of collective acceptance and institutional facts helped explain how shared mental frames become public realities, an idea that underlies Tomasello’s work on cumulative culture.

By supplying precise vocabulary for group agents and collective reasons, Tuomela made it possible for Tomasello to map experimental findings about joint action and shared goals onto rigorous philosophical categories. Overall, Tuomela’s normative and ontological taxonomy functioned as a bridge between philosophical theory and Tomasello’s empirical programme on human cooperation, joint intentionality, and cultural cognition.

Margaret Gilbert

Gilbert’s On Social Facts (1989) is a foundational treatment of social ontology and collective intentionality. Gilbert’s plural-subject account of collective intentionality provided Michael Tomasello with a philosophical vocabulary to describe young children’s emerging "we-relations". Gilbert writes that when people form a plural subject, they adopt

“a shared commitment to act together” and thereby create a sui generis attitude of "we-intention".

Tomasello’s developmental observations — that toddlers coordinate jointly, signal to partners, and treat joint goals as binding — map onto this idea: children do not merely act side-by-side but form a practical “we” with others, matching Gilbert’s claim that “we intend” is neither a mere aggregate nor reducible to separate I‑intentions.

Gilbert’s insistence that joint commitments generate normative roles and accountability also undergirds Tomasello’s emphasis on normative expectations in cooperation. Gilbert argues that plural subjecthood creates “mutual obligations” and that participants can be “liable to blame” one another for failures to perform. Tomasello documents precisely this kind of early normative sensitivity — young children protest broken agreements and expect partners to share duties — showing empirically that joint action carries the kinds of obligations Gilbert described.

The mutual recognition central to Gilbert’s theory — participants standing in relations of joint commitment — reinforces Tomasello’s focus on intersubjective psychology. Gilbert stresses that plural subjects require participants to treat one another as co‑committers: they must “intend together” and acknowledge the shared stance. Tomasello’s experimental work on joint attention, joint goals, and collaborative problem‑solving demonstrates how children come to this mutual stance: they not only coordinate behaviourally but also show awareness that “we are doing this together,” which is exactly the intersubjective condition Gilbert highlights.

Finally, Gilbert’s philosophical move from coordinated action to social fact helps Tomasello link micro‑level cooperation to the emergence of cultural norms and institutions. Gilbert describes how enacted joint commitments create binding social relations — promises, norms and rights — because participants adopt a common standpoint. Tomasello uses this conceptual bridge to argue that the human proclivity for making and enforcing “we‑commitments” is the cognitive foundation for cultural collaboration: small, mutual commitments scale up into collectively binding practices that structure human societies.

John Searle

Searle’s work The Construction of Social Reality (1995) on intentionality and social ontology laid conceptual foundations that Michael Tomasello developed into an empirical programme. Searle argued that many social facts depend on collective mental states:

"We can create social reality by assigning status functions to objects and persons."

These status functions rest on collective acceptance. Tomasello took this idea about socially constructed reality and asked how the psychological capacities that produce it develop, studying how children coordinate attention and intentions to form shared goals.

Searle’s speech-act theory — his claim that utterances are not merely statements but can be actions governed by social rules — helped shape Tomasello’s view of language as a cooperative, intention-reading activity. Searle wrote that “language is intrinsically a social phenomenon,” and Tomasello built on this by showing that children learn words and communicative conventions through joint attention and shared communicative intentions. Where Searle provided an ontological account of how language and institutions depend on collective acceptance, Tomasello supplied the developmental mechanisms by which those capacities emerge.

A key area of overlap is normativity: Searle emphasised that institutions create obligations and rights through collective intentionality, noting that

"Institutions are status-function systems that create deontic powers.”

Tomasello’s experiments reveal early-developing normative expectations — children enforcing rules and holding others to standards — thereby empirically supporting Searle’s claim that social facts carry normative force. However, Tomasello diverges by focusing on cooperation’s evolutionary and psychological roots rather than Searle’s primarily philosophical analysis.

Searle’s notion of collective intentionality as a special kind of "we-intention" influenced Tomasello’s framing of “shared intentionality", but the two theorists emphasise different processes: Searle treats collective intentionality as a social ontology — what makes institutions and group-level facts possible — whereas Tomasello probes the mechanisms (joint attention, joint goals, mutual understanding) that produce shared intentionality in growth and evolution. As Searle put it, social reality “depends on human agreement,” and Tomasello asks how the minds that agree come to be.

Michael Bratman

Michael Bratman's Shared Agency: A Planning Theory of Acting Together (2014) explains shared intention and joint action and clarifies how cooperative planning and shared practical reasoning create cognitive structures for coordinated behaviour, paralleling Tomasello’s developmental emphasis on jointly negotiated goals.

Michael Bratman’s planning theory argues that joint action is constituted by interlocking individual plans: “we intend to J” is analysed through intentions like “I intend that we J", mutual responsiveness, and meshing subplans. Bratman emphasises temporally extended practical reasoning rather than a primitive, collective mind.

Tomasello locates shared intentionality in early-developing, evolutionarily grounded cognitive capacities that enable joint attention, shared goals, and normative expectations. He treats “we” representations as psychological primitives that explain children’s mutual engagement and normative protest.

Bratman’s account affirms that many collective phenomena can be explained by individual planning. Tomasello’s empirical findings challenge this by showing early, affect-laden forms of joint action that seem to involve genuinely shared states. Tomasello highlights normativity — participants treating deviations as breaches — whereas Bratman locates normativity in interlocking intentions and practical reasons.

Major themes

Introduction: The Problem of Human Thinking

Michael Tomasello begins by asking why human thought is different from other primates’. He rejects the idea that human cognition is just a stronger version of ape problem-solving. Instead, he argues that human thinking is fundamentally social: it evolved to coordinate with others in joint activities, to create and follow shared rules, and to build collective symbols and concepts for passing knowledge across generations.

He identifies three linked capacities that make this social cognition possible. First, shared intentionality: humans can form joint goals, share attention, take others’ perspectives, and adopt a “we” stance in interactions. Second, normativity: people learn to judge actions against communal standards, enforce rules, and develop moral and conventional norms. Third, representational systems: language, symbols, and abstract concepts arise from communication and allow more complex reasoning and cultural transmission.

Tomasello supports his account with comparative and developmental evidence. He notes that great apes show limits in cooperative coordination and normative behaviour, while human infants quickly develop joint attention, imitation, and expectations about rules through carer interaction. From these findings he proposes an evolutionary path: cooperative foraging and collective childcare selected for shared-intentionality mechanisms, which made symbolic communication and cultural norms possible and shaped the human mind.

The introduction closes by setting the book’s aim: to bring together evidence from multiple fields to show that sociality and culture are not mere byproducts of cognition but are constitutive of how humans think.

Part I: The Primate Baseline

The Cognitive Capacities of Great Apes

Great apes can solve problems and understand many physical causes. They use tools, plan, innovate, and show flexible means–ends reasoning, but these skills usually show up in individual tasks rather than shared cultural projects. Apes see others as goal-directed agents: they follow gaze, view reaching as intentional, and predict simple actions. This helps them anticipate behaviour and learn by watching, but they lack the cooperative shared-attention system that supports human communication and teaching.

They learn socially through imitation, emulation, and local enhancement, yet their learning is less faithful than humans’. Ape traditions (like chimpanzee and orangutan tool use) exist, but they rarely accumulate complexity across generations as human technologies do. Apes communicate intentionally with gestures and calls, but they show little evidence of shared intentionality, the mutual, collaborative framework humans use to coordinate attention and action. This helps explain why apes don’t engage in cooperative joint projects or develop shared symbolic language systems.

Evidence about apes attributing beliefs is mixed. They track others’ perceptions and goals well but show weak or inconsistent signs of understanding false beliefs. Tomasello treats full theory-of-mind abilities as clearer in human children. Active teaching, norm enforcement, and pedagogy are rare in apes. Humans, by contrast, regularly instruct and enforce conventions, producing high-fidelity cultural transmission that supports cumulative culture.

Apes cooperate and can be prosocial, but their cooperation tends to be situational and limited. Human moral cognition depends on shared norms and impartial enforcement, features largely absent in ape societies. Tomasello argues the key evolutionary difference is social: humans evolved motivations and cognitive skills for shared intentionality — forming joint goals and shared attention — which enabled language, teaching, and cumulative culture, more so than differences in individual intelligence.

Tomasello's evidence combines experiments, developmental studies, and observations, but findings vary by species, upbringing, and methods. He notes limitations and within-species variation, urging cautious interpretation and attention to ecological and developmental context.

Individual Intentionality: Goals, Plans, and Means–End Thinking

"Individual intentionality in great apes manifests as goal‑directed behaviour: apes form ends they want to achieve and organise actions to reach them."

Tomasello describes how apes reliably pursue attainable goals (getting food, accessing tools), persist when obstacles appear, and flexibly switch strategies when circumstances change, showing genuine goal representation rather than mere stimulus‑response chaining.

Apes plan actions and use foresight in simple ways: they anticipate immediate outcomes and sometimes prepare means in advance. Tomasello cites evidence of apes transporting tools, positioning themselves to use objects later, and sequencing actions toward a future benefit, behaviours that indicate short‑range planning and prospective cognition, though typically bounded by immediate motivational and situational constraints.

Means–end reasoning in apes is robust: they understand causal relationships between actions and effects and select appropriate means to achieve goals. Tomasello highlights experiments where apes use tools to retrieve out‑of‑reach food, choose effective causal actions in problem tasks, and infer functionalities of objects rather than copying irrelevant movements, demonstrating causal understanding and pragmatic problem solving.

Apes show behavioural flexibility and insight when standard solutions fail: they innovate novel solutions or recombine known actions to solve new problems. Tomasello notes instances of spontaneous tool modification, inventive problem solving in captivity and the wild, and rapid adoption of alternative tactics when blocked, evidence for mental representation of means and the ability to manipulate them conceptually.

Limitations: planning depth and abstraction are more restricted than in humans. Apes’ foresight is often short‑term and tied to immediate needs. Tomasello argues apes rarely form extended multi‑step plans for distant future goals, show limited evidence of complex hierarchical planning, and are less likely to act for purely informational or long‑term futures compared with humans.

Motivation and individual learning drive much of apes’ intentional action. Social scaffolding that transforms individual plans into shared, cumulative projects is largely absent. Tomasello concludes that while apes possess sophisticated individual intentionality — goals, plans, and means‑end thinking — the social‑cognitive mechanisms that convert these abilities into cooperative cumulative culture in humans are missing or underdeveloped.

Part II The Emergence of Shared Intentionality

Joint Attention and Joint Action

Michael Tomasello argues that uniquely human social cognition rests on two interrelated capacities: joint attention and joint action. Joint attention is the early-emerging ability for two or more individuals to attend to the same external referent while recognising that they are attending together. This triadic interaction — infant, partner, and object or event — appears in the first year of life through behaviours like gaze-following, pointing, and showing. These behaviours function as communicative signals that orient others’ attention and provide the basis for word learning, social referencing, and the development of theory of mind, because infants come to understand others as intentional agents directing attention for a shared purpose.

Building on joint attention, joint action involves coordinated, complementary actions by individuals who understand and pursue a common goal. Joint actions range from simple synchronous behaviours to sophisticated cooperative tasks requiring role differentiation, anticipation of partners’ actions, and mutual commitment. Young children display early forms of joint action in collaborative problem-solving and role negotiation, indicating that they not only act together but also represent shared goals and expectations. This capacity enables coordinated problem-solving, the formation of obligations and norms, and the transmission of cultural practices.

Tomasello frames both abilities within the broader concept of shared intentionality: the psychological stance of participating in collaborative activities with shared goals and mutual understanding. Shared intentionality distinguishes human cooperation from the more individualistic social behaviours observed in other primates. Humans form collective intentions, engage in joint planning, and enforce commitments, which supports complex communication and cumulative culture. Evolutionarily, Tomasello proposes that selection pressures for cooperative foraging and cooperative child rearing favoured individuals who could coordinate attention and action, driving advances in social cognition and language.

The developmental and comparative evidence Tomasello marshals infants’ gaze-following and pointing, toddlers’ collaborative tasks and negotiated roles, and contrasts with apes’ limited cooperative behaviour. From these findings he draws implications for language acquisition, pedagogy, moral development, and social norms: language and teaching arise in contexts of shared attention and action, and joint commitments underlie expectations that form the basis of norms and moral reasoning. In short, joint attention and joint action together create the foundations of human shared intentionality, enabling the complex social, cultural, and communicative life that characterises our species.

The Motivational Foundations: Sharing, Helping, and Cooperating

Human cognitive uniqueness, Tomasello argues, is rooted in shared intentionality: the motivation and skill to form joint goals and think as “we” rather than merely as separate individuals. From infancy, humans are driven to establish common ground: they share attention and emotions, point and follow gaze, and use communicative cues to create mutual understanding. These early social motives set the stage for cooperative problem-solving and the development of language as a tool for coordinating action.

Young children spontaneously help others and share resources without expecting immediate reciprocity, indicating an intrinsic prosocial orientation that precedes formal moral systems. In cooperative interactions they not only coordinate behaviour but also form mutual commitments: they protest broken agreements, enforce social conventions, and hold others to communal standards. Such normative responses show that cooperation generates obligations and expectations, not merely synchronised behaviour.

Comparative evidence highlights a sharp contrast with other great apes, who understand others as intentional agents primarily for competition and do not exhibit the human-style shared intentionality that supports joint commitments and pedagogy. Tomasello traces how the emergence of cooperative motives in the hominin lineage made cumulative culture possible: small-scale joint activities and mutual teaching scale up into durable conventions, institutions, and symbolic systems.

Tomasello situates these empirical findings within philosophical frameworks — drawing on Vygotsky’s social origin of higher cognition, Wittgenstein’s meaning-as-use, Tuomela’s we-/I-mode distinction, Gilbert’s plural subject and joint commitment, and Searle’s social ontology — to show how micro-level intersubjective psychology becomes the basis for cultural facts. Ultimately, the drives to share, help, and cooperate transform individual learning into cultural transmission, enable rule-following and moral protest, and explain key differences between human and nonhuman primate cognition.

Pointing, Gestures, and the Origins of Communication

Tomasello argues that human communication grew out of a special ability to share attention and intentions with others. Unlike other primates, humans point and use gestures not just to get things but to share interest and create joint attention. This shared intentionality — wanting to coordinate with others — makes cooperative communication possible. Pointing serves two main purposes. Imperative pointing asks for something, like wanting a toy. Declarative pointing, which is more important for language, is used to show or share interest in something. Babies start pointing around 9–12 months, and these gestures help them learn words because carers respond and build joint attention routines.

Comparisons with great apes show that while apes can communicate, they rarely use declarative pointing or naturally form joint attentional states. Tomasello sees this as a key difference: humans have similar cognitive skills in some ways but uniquely strong motives and abilities for cooperation. Over time, intentional gestures and repeated social interaction become conventionalised into symbols — words — and this process leads to language. Crucially, effective communication depends on recognising others’ communicative intentions. Listeners assume cooperation, and speakers tailor messages accordingly.

Tomasello’s view is that selection for cooperative behaviours — like group foraging and childcare — favoured shared intentionality. This social-cognitive shift, more than raw intelligence, allowed humans to develop cooperative communication, teaching, and cumulative culture.

Part III: From Shared Intentionality to Collective Cognition

Collective Intentionality and Group-Mindedness

Michael Tomasello argues that humans are uniquely adapted for shared intentionality — the set of cognitive and motivational capacities that allow individuals to coordinate attention, intentions, and actions toward common goals. This capacity for jointly orientated cognition emerges early in development: infants show joint attention and pointing gestures, and toddlers rapidly progress to role-differentiated cooperation, joint commitments, and enforcement of norms. Tomasello contrasts this with great apes, who can cooperate on tasks but typically lack the motivational and socio-cognitive mechanisms for genuine joint intentions, shared goals, and the kind of normative enforcement seen in human children.

Central mechanisms include joint attention (triadic coordination of self, other, and object), mindreading abilities that recognise others’ intentions, and communicative scaffolding — especially language and pedagogy — that both arise from and amplify shared intentionality. These mechanisms produce group-mindedness: individuals adopting “we” perspectives, internalising group norms, and experiencing collective emotions such as pride and shame. Common ground — accumulated shared knowledge and assumptions — supports smooth interaction and cultural transmission across generations.

The social consequences of shared intentionality are profound. It underlies cooperative problem-solving, teaching, and cumulative culture, enabling large-scale institutions and normative systems. Children’s early tendencies to help, share, and enforce rules suggest intrinsic prosocial motivations that scaffold moral behaviour and social conformity. Tomasello’s account emphasises growth and social interaction. These capacities develop through repeated engagement with carers and peers in culturally structured contexts.

Critics question the sharpness of the human–ape divide, pointing to continuities and cultural variability in shared intentionality’s expression, and researchers continue to investigate the neural bases and precise evolutionary pathways. Nevertheless, Tomasello’s framework reframes many human social phenomena — language, morality, institutions, and cultural accumulation — as rooted in uniquely human capacities for joint attention, shared intentions, and group-mindedness.

The Development of Norms and Social Conventions

Human norms arise from shared intentionality in early cooperative interactions. Tomasello says children develop a “we‑intentionality” that makes actions feel like “collective commitments", prompting protests, repairs, and enforcement. Conventions (arbitrary coordination rules, “how we do things”) differ from moral norms (concerned with welfare and fairness). Teaching and generic labelling (e.g., “This is how we do it”) accelerate turning routines into general, prescriptive rules.

By preschool age children enforce norms as third parties. Showing norms becomes “public, shared facts” tied to group identity. Cognitive skills — perspective‑taking and representing group facts — enable this shift, allowing large‑scale cooperation and cultural transmission.

Teaching, Imitation, and Cultural Transmission

Michael Tomasello argues that uniquely human cooperative motives and shared intentionality underlie our species’ capacity for teaching, imitation, and cultural transmission. Humans are predisposed to engage with others as collaborators: from early infancy we seek joint attention and mutually understand goals, which makes explicit pedagogy possible. Teaching in humans therefore emerges not merely as information transfer but as a social activity aimed at helping others learn for the sake of shared goals and maintaining social relationships.

Imitation, in Tomasello’s view, is selective and sophisticated compared with other primates. Young children imitate not only overt actions but also underlying intentions and normative practices. They overimitate — copying irrelevant actions — because they infer that adult intentionality signals culturally relevant conventions. This propensity supports fidelity in transmitting complex behaviours and norms across generations, since learners assume that modelled behaviours carry social and conventional meaning beyond instrumental utility.

Cultural transmission, then, is the cumulative result of teaching and high-fidelity imitation within social groups that share communicative conventions and normative expectations. Tomasello emphasises that human culture is constructed and ratified through shared norms: individuals not only learn techniques but also internalise reasons, rules, and group-specific points of view. Over time, these processes produce cumulative culture — technologies, institutions, and symbolic systems — that no single individual could invent alone, because social cognition both motivates cooperative teaching and channels imitation toward stable, normative patterns.

Part IV: Language, Thought, and Cultural Evolution

Language as a Tool for Coordinated Thought

Michael Tomasello argues that human language evolved not merely as a system for labelling the world but primarily as a social tool that enables shared intentionality and coordinated cognition. He emphasises that the distinctive feature of human communication is its cooperative, cultural nature. Children are socialised into practices of joint attention, common ground, and perspective-taking, which ground linguistic meaning in shared goals and intentions. Language, in this view, scaffolds cooperative problem-solving by making mental states publicly accessible and alignable among individuals.

Tomasello distinguishes between two core capacities that underlie language’s role in thought. First is the ability to coordinate attention and intentions with others (joint attention, joint intentionality), which creates a shared representational space. Second is the capacity for intentional, inferential communication. Speakers produce signals with the expectation that addressees will interpret them based on cooperative assumptions. Together these capacities allow group members to form and manipulate representations that are effectively communal rather than purely private.

Because language makes it possible to externalise and objectify perspectives, it transforms individual cognition. Verbal labels and syntactic constructions function as public handles on concepts and procedures, enabling cumulative cultural learning, abstract reasoning, and the transmission of normative practices. Tomasello shows how linguistic forms both reflect and shape collective cognitive processes. Grammar organises predicates and relations in ways that support planning, explanation, and causal reasoning across individuals.

Developmental evidence is central: Tomasello reviews how infants progress from twofold engagement to triadic joint attention, then to using words and conventional signs to direct and coordinate others. Children learn words not just by association but by grasping their conventional, normative status within a community. Understanding that words are used intentionally to refer within shared practices. This social-pragmatic route explains children’s rapid acquisition of communicative norms and their early capacity for cooperative problem solving.

Tomasello links language-driven coordination to uniquely human cultural phenomena: collective intentionality enables institutions, norms, and cumulative technological progress because language allows people to coordinate complex plans, negotiate perspectives, and transmit abstract rules across generations. Thus, language is both a product of cooperative cognition and a principal engine that expands and stabilises coordinated thought at the cultural scale.

Representation of Norms, Obligations, and Institutions

Tomasello begins by asserting that humans uniquely construe social life through shared rules and obligations:

“It is only by virtue of shared intentionality that we can represent others’ behaviour as being governed by normative standards that are objective and generalisable rather than merely idiosyncratic preferences.”

This capacity, he argues, underlies cooperation at all scales. He outlines a developmental pathway: early joint attention and proto-cooperative routines lead children into collaborative activities where they learn commitments. A key representational transformation is moving from twofold, ego-relative commitments to group-level, agent-neutral norms. As Tomasello puts it, children shift from an “I/you” understanding of obligations to a “we” perspective in which rules are treated as publicly binding.

He draws an explicit distinction between moral norms and social conventions, emphasising different sources of bindingness. Moral norms — those concerning harm, fairness, and rights — are experienced as intrinsically binding and not merely contingent on local authority, whereas conventional norms depend on collective agreement and the authority that sustains them. This explains why children often treat harm-based transgressions as wrong even if no rule-giver is present.

On institutions, Tomasello emphasises constitutive rules and collective acceptance:

“Institutions are cultural forms built on collective intentionality; something X counts as Y in context C only because people collectively say it does.”

Institutional facts gain objective force through joint recognition and are stabilised across generations by language and pedagogical practice. Explicit teaching and shared symbols allow institutions to be transmitted and maintained beyond immediate cooperative contexts.

He locates the cognitive mechanisms enabling these representations in normative attitudes and recursive perspective-taking:

“Children develop the capacity to take normative attitudes, to expect conformity, to reproach violators, and to hold others to standards and recursive mindreading (‘I know that you know that we expect…’) allows obligations to be represented as public and binding.”

These representational tools let obligations be transferred, attributed to roles, and enforced socially. Social motivation is central to internalising norms. Tomasello emphasises that humans are motivated to participate in joint action and concerned with reputation. An intrinsic desire for social inclusion and concern for reputation drive individuals to adopt and enforce group norms. This motivational substrate makes normative adherence not merely instrumental but identity-relevant.

From an evolutionary perspective, he frames these capacities as adaptations for cooperation. The human lineage evolved more advanced mechanisms for jointly representing and enforcing group-wide norms and institutions than other primates, enabling large-scale cooperation. This evolutionary account ties the developmental trajectory to selection pressures favouring coordinated group action.

The author ends by linking theory to empirical phenomena: toddlers’ early norm enforcement, preschoolers’ explanations of rules, and the persistence yet malleability of institutions. He summarises that the combination of shared intentionality, perspective-taking, pedagogy, and social motivation produces social facts that are “collectively recognised" and thus enjoy an appearance of objectivity and binding force.

Cumulative Culture and Abstract Thought

Tomasello links cumulative culture to uniquely human social–cognitive capacities:

“While many species have traditions, only humans build complex, open-ended cultural systems” because they can “imitate faithfully, teach intentionally, and innovate while preserving useful modifications.”

This triad, he argues, is what allows incremental improvements to accumulate across generations. He emphasises high-fidelity social learning — imitation, teaching, and normative instruction — as essential for preservation and transmission. Tomasello notes that children do not merely copy outcomes but adopt procedural knowledge through pedagogy and ostensive communication, which lets small innovations “stack” into complex technologies and practices.

A central claim is that cumulative culture and abstract cognition co-evolve. Participating in cultural practices fosters "decontextualised thought”: skills and concepts become represented independently of immediate contexts, enabling causal reasoning, rule abstraction, and hypothetical thinking. These abstract capacities in turn “fuel cultural innovation” by allowing recombination and generalisation of ideas.

Shared intentionality and collaborative problem-solving create environments for coordinated improvement and evaluation. Tomasello writes that joint goals produce “norms about best practices” that scaffold retention of innovations by standardising procedures and making them teachable. Language and symbolic representation greatly amplify cultural accumulation. Language permits explicit transmission of “abstract rules, causal explanations, and normative claims", stabilising knowledge beyond what observation alone can convey and enabling cumulative elaboration in domains like mathematics and science.

Developmentally, Tomasello shows that children shift from context-bound skills to conceptual understanding through participation in pedagogical contexts: "Adults intentionally teach by highlighting generalisable features and reasons for practices,” promoting abstraction rather than mere mimicry. He closes by framing cumulative culture and abstract thought as a reinforcing evolutionary feedback loop. Social learning, teaching, language, and cooperative motives enable accumulation, which selects for cognitive mechanisms of abstraction and recombination, explaining humans’ unparalleled technological and institutional complexity.

Part V: Developmental and Comparative Evidence

Infant Studies: Early Manifestations of Shared Intentionality

Tomasello reviews experimental infant studies showing early roots of shared intentionality, arguing that basic cooperative skills appear within the first two years and form the foundation for later cultural cognition. He begins by describing joint attention and pointing as early communicative acts that coordinate attention and intention between infant and adult: “pointing is a triadic, declarative act” that shows infants’ desire to share focus and interest rather than merely to request objects.

He summarises research on joint action and collaboration, noting that by 9–12 months infants engage in coordinated routines with carers and anticipate partners’ roles. Tomasello reports that infants not only follow others’ gaze but also correct partners’ actions to restore a shared goal, demonstrating an early sense of joint commitment: infants behave as if there is “a mutual obligation” to the collaborative task.

The author highlights infants’ prosocial motivations — helping and sharing — that emerge early and are selectively directed toward cooperative partners. He emphasises that infants help instrumentally without explicit reward, suggesting an intrinsic orientation to participate in others’ goals:

“Infants help to assist others’ goals, not for immediate material gain but to engage in common projects.”

He discusses experiments showing infants’ sensitivity to intentionality and fairness: infants differentiate accidental from intentional acts and show expectations about equitable treatment in resource distribution. These findings indicate they form simple normative judgements and can represent others as agents with obligations and rights.

Tomasello places special weight on communicative pedagogy: when adults use ostensive cues (eye contact, infant-directed speech), infants treat demonstrations as teaching and generalise the information across contexts. He writes that such pedagogy signals that what is being shown is "generalisable knowledge” rather than a one-off event.

He argues that these early manifestations — joint attention, cooperative routines, prosocial motivation, sensitivity to intention and fairness, and responsiveness to pedagogy — together constitute the developmental beginnings of shared intentionality. These skills provide the cognitive and motivational scaffolding for later normative understanding, cultural learning, and collective intentionality that characterise human social life.

Experimental Comparisons with Apes and Children

Tomasello opens by contrasting apes’ and children’s basic social cognition: both species “understand others as intentional agents,” but only children readily form joint, shared goals. He writes that apes “perceive others as agents” yet lack the propensity to adopt “we‑intentions” that characterise human cooperation. In joint attention and communicative acts, children point declaratively to share attention and information, whereas apes rarely do so. Tomasello states, "Pointing is triadic” in humans — it establishes a shared psychological space while apes “follow gaze less flexibly and seldom initiate informative pointing.”

On collaborative problem solving, toddlers coordinate roles, expect partners to fulfil commitments, and protest breakdowns, acting as if there is “a mutual obligation” to the joint task. Apes can coordinate when it’s directly beneficial but show less spontaneous role differentiation and less insistence on partner obligations; cooperation for them is more “opportunistic coordination". Normative cognition marks a sharper divide: preschoolers enforce rules on others and distinguish moral from conventional violations, representing norms as generalisable standards. Tomasello emphasises that apes do not systematically enforce group norms or represent impersonal, group‑level obligations since they lack the sense that certain behaviours “ought” to be done by everyone.

Prosocial behaviours appear in both species, but their bases differ. Human infants help and share in ways tied to reputation and collective motives — helping to participate in shared projects — whereas apes’ helping is more contingent on direct relationships or immediate reward. Tomasello notes human prosociality is embedded in shared intentionality and normative expectations. He concludes that experimental comparisons point to shared intentionality — joint attention, shared goals, normative reasoning, and pedagogy — as the cluster of capacities that uniquely enable children to create, teach, and enforce collective norms and institutions in ways apes do not.

Part VI Evolutionary Scenarios

Ecological and Social Pressures for Cooperation

Tomasello argues that human cooperation evolved in response to ecological and social pressures that made solo foraging and lone action less viable, favouring individuals who could coordinate flexibly in groups. Facing patchy resources, coordinated hunting, and the need to share food reliably, early humans benefited from cooperative strategies that required mutual commitment, role differentiation, and trust—features that could outcompete solitary competitors. He emphasises interdependence: tasks like group hunting, collective childrearing, and defence created stable payoffs only when members reliably contributed. Tomasello writes that such interdependence selected for psychological mechanisms supporting shared goals and expectations of reciprocity, because opportunistic freeloading would otherwise undermine group success.

Social complexity and larger group sizes increased demands for coordination, communication, and reputation management. As groups grew, individuals needed ways to standardise practices and enforce cooperation across diffuse networks, promoting the emergence of norms, punishment, and reputation-sensitive behaviour as solutions to cooperation problems. Tomasello highlights niche construction and cultural scaffolding. Once cooperative routines and institutions arose, they created environments that further favoured learners who could engage in teaching, imitation, and norm-following. Language and pedagogy amplified the transmission of cooperative skills, allowing cumulative improvements in tools and social organisation that reinforced cooperative dispositions.

Tomasello frames these pressures as producing a feedback loop: ecological and social challenges selected for shared intentionality, prosocial motivation, and normative cognition, which enabled larger-scale cooperation and cultural accumulation. In turn, those cultural innovations changed selective environments, further entrenching cooperative psychology.

A Gradual Path to Human Thinking

Tomasello proposes a gradual, multi-step evolutionary and developmental trajectory from ape-like cognition to fully human shared-intentional, normative, and cultural thinking. He rejects sudden, single-mutation accounts and instead frames human cognitive uniqueness as emerging from incremental changes in social motivation, cognitive capacities, and cultural practices. Early steps involve enhanced social motivation and tolerance. Small increases in prosociality and tolerance for others’ presence allowed more frequent, repeated cooperative interactions. Tomasello argues these shifts made sustained joint activities possible, creating selection pressure for better coordination and communication.

Next come cognitive and communicative elaborations that support joint action. Improved gaze-following, intentional signalling, role-taking, and rudimentary teaching. These capacities let individuals form genuine joint goals rather than merely coordinating behaviour incidentally, producing durable dyadic cooperation and simple collective practices. As cooperative routines spread, normative cognition and shared intentionality deepen. Individuals begin to represent commitments as mutual obligations and to expect conformity and enforcement. Tomasello describes this as a move from that underpin group norms, conventions, and institutions.

Language and pedagogy co-evolve with these social-cognitive advances, enabling high-fidelity transmission, explicit instruction, and abstraction. With symbolic communication, practices become teachable and generalisable, supporting cumulative cultural accumulation and the development of abstract conceptual systems separate from immediate contexts. Tomasello frames the whole process as a feedback loop: ecological and social pressures favour small changes in social behaviour and cognition. Those changes generate cultural innovations and institutions that create new selection pressures for further cognitive enhancement. Gradually, this iterative process yields humans’ capacities for shared intentionality, normative judgement, abstract thought, and large-scale cultural complexity.

Conclusion: Implications for Psychology, Anthropology, and Education

Tomasello concludes that recognising shared intentionality, normative cognition, and cumulative culture as core human capacities has broad implications across psychology, anthropology, and education.

For psychology, he argues research should focus on developmental trajectories that link early joint attention and prosocial motivation to later normative reasoning, pedagogy, and abstract thought, studying mechanisms of cooperation, teaching, and norm enforcement rather than treating cognition as purely individualistic.

In anthropology, Tomasello suggests reinterpreting human cultural diversity as variations built on a common shared‑intentional substrate. Institutions, norms, and technologies are culturally specific elaborations of general capacities for collective intentionality and normative representation, so comparative work should trace how ecological and social contexts shape different institutional forms.

For education, he emphasises harnessing humans’ proclivity for pedagogy and collaborative learning. Teaching that makes generalisable principles explicit, structures joint problem solving, and fosters mutual obligations will better cultivate abstract reasoning and cultural transmission. Formal schooling should leverage social motivation, normative frameworks, and guided participation to promote cumulative learning.

Across disciplines he advocates integrative approaches that connect evolution, development, and culture, investigating how social motivations, communicative practices, and institutional scaffolds interact to produce uniquely human cognition and how those processes can be supported or transformed in applied settings.