Humans do many things together collaboratively as joint agents or in groups as collective agents. It turns out that these ways of operating together as a “we” have a number of special properties as compared with the cooperative interactions of other animal species. Most important are humans’ special ways of thinking in terms of perspectives, their special ways of regulating social interactions normatively and morally, and the special ways that their cultural groups structure everything via conventions, norms, and institutions that ratchet up in complexity over historical time.

History

Beginning in the 1990s, the philosopher of action Michael Bratman (1992, 2014) identified what he called shared cooperative activities and outlined some of the unique psychological processes at work when two people paint a house together or cook a meal together collaboratively. The philosopher of intentionality John Searle (1995, 2010) identified what he called collective intentionality and outlined some of the unique psychological processes at work when groups of people collectively recognize a comrade as a president or a piece of paper as money.

In the early 2000s, Tomasello and Rakoczy (2003) and Tomasello et al. (2005) investigated how these processes of shared intentionality emerged in human evolution and how they emerge in human ontogeny [see Cognitive Development]. Tomasello (2014, 2016, 2019) distinguished between joint intentionality, involving individuals collaborating with one another, and collective intentionality, involving individuals interacting within a cultural group structured by cultural conventions, norms, and institutions. The proposal is that these processes are unique to humans—because at some point in human evolution individuals became interdependent with one another for survival—and they are responsible for humans’ unique forms of cooperation and cultural organization. Tomasello (2022, 2024) argued that the broadest perspective on these phenomena is in terms of human agency: humans (and only humans) form joint agencies and collective agencies.

Core concepts

To form a joint agency with a joint goal, each participant must have the goal that they act together, and they must also know together in common ground that they both share this goal. Each partner has their own individual role in the joint agency that they must coordinate with their partner’s role. Working together toward a joint goal requires joint attention to things relevant to the joint goal, with each partner having their own individual perspective. In the ideal case, participants engage in cooperative communication (acts aimed at informing the partner of things helpful to their role) to facilitate a joint decision. Participants may be tempted to opt out of the joint agency and so may begin by making a joint commitment (A: “Want to X?”; B: “Sure”), which entitles each of them to rebuke the other normatively for not playing their role in the ideal way or for not sharing the spoils of the joint activity in a manner fair to both (“You should/should not X”; Gilbert, 2003, 2014).

Human groups may form collective agencies—prototypically cultural groups—with collective goals based in collective (or cultural) common ground. To facilitate coordination among in-group strangers, groups develop conventions—including communicative (linguistic) conventions—to which individuals simply conform. To become a full-fledged member of a cultural group, individuals join into a collective commitment to the social norms of the group, which obligates them not only to conform but to engage in norm enforcement to make sure that others conform as well (Tomasello, 2020) [see Normativity]. Cultural institutions are organized collections of social roles and norms for specific societal purposes. Failure to join into a collective commitment to the norms of the group leads to a loss of one’s cooperative identity in the group. Adults in a cultural group instruct youngsters with prosocially motivated and normatively framed pedagogy (“this is how it should be done”), to which youngsters normatively conform, leading to a cultural ratchet effect in which both material and symbolic artifacts (from spears to language) increase in complexity over cultural-historical time [see Cultural Evolution].

Questions, controversies, and new developments

Many comparative studies have purported to show that shared agency and intentionality are unique to humans among primates, suggesting further that this fact explains how and why only humans have come to live in cultural groups that create and maintain complex cultural artifacts and practices based on cultural conventions, norms, and institutions [see Animal Cognition]. Other researchers have disputed this claim with comparative studies suggesting that nonhuman great apes (especially chimpanzees and orangutans) may also live in cultures, form joint and collective agencies, make joint commitments, engage in joint attention, create conventions and norms, and communicate cooperatively and even linguistically (see Heesen & Fröhlich, 2022). If nonhuman great apes do in fact engage in all these shared intentional activities, it is unclear why this has not led to their creating human-like cultural artifacts and practices.

The newest developments in shared intentionality theory explain the evolution and development of individual psychological processes in terms of the evolution and development of agentive action and its control system organization: organisms make cognitively informed decisions to produce adaptive goal-directed actions, which are naturally selected (Tomasello, 2022, 2024). This foundation prepares for a smooth transition evolutionarily and developmentally to human shared agency, in which individuals coordinate their individual psychological agencies to produce adaptive social and cultural actions. Humans’ adaptations for functioning as both individual and shared agents are responsible for many or most of humans’ unique psychological capacities.

Broader connections

Traditionally, cognitive psychology and cognitive science have focused on the individual and their individual cognitive processes. The argument from shared intentionality theory is that many of humans’ most powerful cognitive processes came into existence evolutionarily and come into existence ontogenetically, in order to deal with the challenges of human social and cultural life. These include recursive thinking (to coordinate with others in shared agencies), objective thinking (to resolve perspectival disputes with others), and sociomoral and normative concepts and attitudes (to resolve preference disputes with others). Moreover, humans could not function as they do cognitively without collectively produced cultural products, beginning most importantly with language but also including other symbolic artifacts such as Arabic numerals and material artifacts of various kinds, from bows and arrows to telephones and computers [see Language]. The perspective from shared intentionality thus provides a bridge from psychology and cognitive science to surrounding fields in the behavioral and social sciences, from anthropology to legal studies.

Further reading

• Heesen, R., & Fröhlich, M. (2022). Revisiting the human ‘interaction engine’: Comparative approaches to social action coordination. Philosophical Transactions of the Royal Society B, 377, 20210092. https://doi.org/10.1098/rstb.2021.0092

• Searle, J. R. (1995). The construction of social reality. The Free Press.

• Tomasello, M. (2019). Becoming human: A theory of ontogeny. Harvard University Press. https://doi.org/10.4159/9780674988651