Olle Blomberg

Leading philosophical accounts of joint activity, such as Michael Bratman’s account of ‘shared intentional activity’, take joint activity to be the outcome of two or more agents having a ‘shared intention’, where this is a certain pattern of mutually known prior intentions that are directed toward a common goal. With Bratman’s account as a foil, I address two lacunas that are relatively unexplored in the philosophical literature. The first lacuna concerns how to make sense of the apparently joint cooperative activities of agents that lack the capacities for planning and “mindreading” that one must have in order to be a party to a shared intention. The second lacuna concerns how participants are able to coordinate their actions “online”—that is, during action execution as a joint activity unfolds—without recourse to plans that specify in advance what they should do. Chapters 2 and 3 focus on the first lacuna, while chapters 4 and 5 focus on the second. In chapter 2, I focus on why participants must have mutual or common knowledge of each other’s intentions and beliefs in order to have a shared intention: Why must these attitudes be “out in the open”? I argue that, if participants lack the concept of belief, then one of the two main motivations for the common knowledge requirement—to filter out certain cases that intuitively aren’t cases of genuine joint activity—actually dissipates. Furthermore, a kind of “openness” that only requires of participants that they have the concept of goal but not that of belief can satisfy the other main motivation, to make sense of the idea that joint activities are non-accidentally coordinated. In chapter 3, I offer an account of a kind of joint activity in which agents such as young children and some non-human primates could participate, given what we know about their socio-cognitive capacities. In chapter 4, I argue that ‘shared intention’-accounts are unable to say much about spontaneous or skilful joint action because of the following widely accepted constraint on what one can intend: while an agent might intend—in the sense of commit to a plan—that “we” do something together, an agent cannot intend to perform “our” joint action. I reject this constraint and argue that some joint actions are joint in virtue of each participant having what I call ‘socially extended intention-in-action’ that overlap. In chapter 5, I review empirical work on subpersonal enabling mechanisms for the coordination of joint action. The review provides clues to what it is that enables participants to successfully coordinate their actions in the absence of plan-like intentions or beyond what such intentions specify. While what I address are lacunas rather than problems, an upshot of this thesis is that leading philosophical accounts of joint activity may have less explanatory scope than one might otherwise be led to believe. The accounts of joint activity and joint action that are presented in this thesis are arguably applicable to many of the joint activities and joint actions of adult human beings. The account also helps us avoid the false dichotomy between a very robust form of joint activity and a mere concatenation of purely individualistic actions—a dichotomy that accounts such as Bratman’s arguably invite us to adopt.

In 'Joint Action and Development', Stephen Butterfill argues that if several agents' actions are driven by what he calls a "shared goal"—a certain pattern of goal-relations and expectations—then these actions constitute a joint action. This kind of joint action is sufficiently cognitively undemanding for children to engage in, and therefore has the potential to play a part in fostering their understanding of other minds. Part of the functional role of shared goals is to enable agents to choose means that are appropriate to realising a goal with others rather than individually. By offering a counterexample, I show that the pattern of goal-relations and expectations specified by Butterfill cannot play this role. I then provide an appropriately conceptually and cognitively undemanding amendment with which the account can be saved.

Philosophical accounts of joint action are often prefaced by the observation that there are two different senses in which several agents can intentionally perform an action Φ, such as go for a walk or capture the prey. The agents might intentionally Φ together, as a collective, or they might intentionally Φ in parallel, where Φ is distributively assigned to the agents, considered as a set of individuals. The accounts are supposed to characterise what is distinctive about activities in which several agents intentionally Φ collectively rather than distributively. This dualism between joint and parallel action also crops up outside philosophy. For instance, it has been imported into a debate about whether or not group hunting among chimpanzees is a form of joint cooperative hunting. I offer an account of a form of joint action that falls short of what most philosophers take to be required for genuine joint action, but which is not merely parallel activity. This shows that the dualism between the genuinely joint and the merely parallel is false. I offer my account as an explication of an influential definition of “cooperative behaviour” given by the primatologists Christophe and Hedwig Boesch.

Cognitive processes, cognitive psychology tells us, unfold in our heads. In contrast, several approaches in cognitive engineering argue for a shift of unit of analysis from what is going on in the heads of operators to the workings of whole socio-technical systems. This shift is sometimes presented as part of the development of a new understanding of what cognition is and where the boundaries of cognitive systems are. Cognition, it is claimed, is not just situated or embedded, but extended and distributed in the world. My main question in this article is what the practical significance is of this framing of an expanded unit of analysis in a cognitive vocabulary. I focus on possible consequences for how cognitive engineering practitioners think about function allocation in system design, and on what the relative benefits and costs are of having a common framework and vocabulary for talking about both human and technical system components. I argue for what I call an *expansive but deflated conception of cognition*, primarily on pragmatic grounds. In addition, I claim that the important lesson of the “boundaries of cognition” debate in cognitive science is the negative claim that there is not anything special about the biological boundary of the skin and skull per se, rather than some positive claim about where the boundaries of extended or distributed cognitive systems really are. I also examine the role of the concept of cognition in the theoretical frameworks of distributed cognition, joint cognitive systems (also known as cognitive system engineering), and cognitive work analysis.

What is required for several agents to intentionally φ together? I argue that each of them must believe or assume that their φ-ing is a single end that each intends to contribute to. Various analogies between intentional singular action and intentional joint action show that this doxastic single end condition captures a feature at the very heart of the phenomenon of intentional joint action. For instance, just as several simple actions are only unified into a complex intentional singular activity if the agent believes or assumes that there is a single end that each action is directed to, so several agents’ actions are only unified into an intentional joint activity if each agent believes or assumes that there is a single end that each intends to contribute to. Influential accounts of intentional joint action, including Christopher Kutz’s and Michael Bratman’s, implicitly include this condition only if participants must intend to contribute to the end under the same conception. While such a requirement successfully rules out some counterexamples, it also makes the accounts unable to appropriately accommodate and explain clear cases of intentional joint action that they ought to be able to accommodate and explain

Most reductionist accounts of intentional joint action include a condition that it must be common knowledge between participants that they have certain intentions and beliefs that cause and coordinate the joint action. However, this condition has typically simply been taken for granted rather than argued for. The condition is not necessary for ensuring that participants are jointly responsible for the action in which each participates, nor for ensuring that each treats the others as partners rather than as social tools. It is thus something of a mystery why the condition is so widely accepted. By rejecting three arguments that could potentially support it, I argue that reductionists should get rid of the condition. I show that two of the arguments fail. While the third argument is intuitively compelling, it builds on key premises that are unavailable to the reductionist.