Stephen Andrew Butterfill

Psychological research into children’s sensitivity to testimony has primarily focused on their ability to judge the likely reliability of speakers. However, verbal testimony is only one means by which children learn from others. We review recent research exploring children’s early social referencing and imitation, as well as their sensitivity to speakers’ knowledge, beliefs, and biases, to argue that children treat information and informants with reasonable scepticism. As children’s understanding of mental states develops, they become ever more able to critically evaluate whether to believe new information

Current theory-of-mind research faces the challenge of reconciling two sets of seemingly incompatible findings: Whereas children come to solve explicit verbal false belief tasks from around 4years of age, recent studies with various less explicit measures such as looking time, anticipatory looking, and spontaneous behavior suggest that even infants can succeed on some FB tasks. In response to this tension, two-systems theories propose to distinguish between an early-developing system, tracking simple forms of mental states, and a later-developing system, based on fully developed concepts of belief and other propositional attitudes. One prediction of such theories is that the early-developing system has signature limits concerning aspectuality. We tested this prediction in two experiments. The first experiment showed that 2- and 3-year-olds take into account a protagonist's true or false belief about the location of an object in their active helping behavior. In contrast, toddlers' helping behavior did not differentiate between true and false belief conditions when the protagonist's belief essentially involved aspectuality. Experiment 2 replicated these findings with a more stringent method designed to rule out more parsimonious explanations. Taken together, the current findings are compatible with the possibility that early theory-of-mind reasoning is subject to signature limits as predicted by the two-systems account.

What could someone represent that would enable her to track, at least within limits, others' perceptions, knowledge states and beliefs including false beliefs? An obvious possibility is that she might represent these very attitudes as such. It is sometimes tacitly or explicitly assumed that this is the only possible answer. However, we argue that several recent discoveries in developmental, cognitive, and comparative psychology indicate the need for other, less obvious possibilities. Our aim is to meet this need by describing the construction of a minimal theory of mind. Minimal theory of mind is rich enough to explain systematic success on tasks held to be acid tests for theory of mind cognition including many false belief tasks. Yet minimal theory of mind does not require representing propositional attitudes, or any other kind of representation, as such. Minimal theory of mind may be what enables those with limited cognitive resources or little conceptual sophistication, such as infants, chimpanzees, scrub-jays and human adults under load, to track others' perceptions, knowledge states and beliefs.

Our motor system can generate representations which carry information about the goals of another agent's actions. However, it is not known whether motor representations play a deeper role in social understanding, and, in particular, whether they enable tracking others' beliefs. Here we show that, for adult observers, reliably manifesting an ability to track another's false belief critically depends on representing the agent's potential actions motorically. One signature of motor representations is that they can be disrupted by constraints on an observed agent's action capacities. We therefore used a `mummification' technique to manipulate whether the agent in a visual ball-detection task was free to act or whether he was visibly constrained from acting. Adults' reaction times reliably reflected the agent's beliefs only when the agent was free to act on the ball and not when the agent was visibly constrained from acting. Furthermore, it was the agent's constrained action capabilities, rather than any perceptual novelty, that determined whether adult observers' reaction times reliably reflected the agent's beliefs. These findings signal that our motor system may underpin more of social cognition than previously imagined, and, in particular, that motor representations may underpin automatic false-belief tracking.

People walk, build, paint and otherwise act together with a purpose in myriad ways. What is the relation between the actions people perform in acting together with a purpose and the outcome, or outcomes, to which their actions are directed? We argue that fully characterising this relation will require appeal not only to intention, knowledge and other familiar philosophical paraphernalia but also to another kind of representation involved in preparing and executing actions, namely motor representation. If we are right, motor representation plays a central role in the story of acting together.

Anyone who has ever walked, cooked or crafted with a friend is in a position to know that acting jointly is not just acting side-by-side. But what distinguishes acting jointly from acting in parallel yet merely individually? Four decades of philosophical research have yielded broad consensus on a strategy for answering this question. This strategy is \emph{mechanistically committed}; that is, it hinges on invoking states of the agents who are acting jointly (often dubbed ‘shared’, ‘we-’ or ‘collective’ intentions). Despite the consensus, enduring disagreement remains. The disagreement may be a consequence of the strategy; at least this is plausible enough to motivate considering the prospects for an alternative. Our aim is therefore to draw attention to a coherent alternative that is present in the literature but often overlooked. This alternative is \emph{mechanistically neutral}: it avoids invoking states of agents. Implementing the alternative, we introduce the notion of a collective goal and a characterisation of acting jointly which meets criteria standardly used in evaluating other accounts and may have some advantages over those accounts.

ABSTRACT In what sense is commitment essential to joint action, and do the participants in a joint action themselves perceive commitment as essential? Attempts to answer this question have so far been hampered by clashes of intuition. Perhaps this is because the intuitions in question have mostly been investigated using informal methods only. To explore this possibility, we adopted a more formal approach to testing intuitions about joint action, sampling naïve participants’ intuitions about experimentally controlled scenarios. This approach did reveal patterns in participants’ responses which may hint at potential conceptual links between commitment and joint action. It did not however provide evidence to support the view that commitment is essential to joint action, at least not from the agents’ own perspective. We conclude that intuitions alone, even when drawn systematically from a large sample, may be a poor basis for theorizing about joint action.

People walk, build, paint and otherwise act together with a purpose in myriad ways. What is the relation between the actions people perform in acting together with a purpose and the outcome, or outcomes, to which their actions are directed? We argue that fully characterising this relation will require appeal not only to intention, knowledge and other familiar philosophical paraphernalia but also to another kind of representation involved in preparing and executing actions, namely motor representation. If we are right, motor representation plays a central role in the story of acting together.

Our motor system can generate representations which carry information about the goals of another agent's actions. However, it is not known whether motor representations play a deeper role in social understanding, and, in particular, whether they enable tracking others' beliefs. Here we show that, for adult observers, reliably manifesting an ability to track another's false belief critically depends on representing the agent's potential actions motorically. One signature of motor representations is that they can be disrupted by constraints on an observed agent's action capacities. We therefore used a `mummification' technique to manipulate whether the agent in a visual ball-detection task was free to act or whether he was visibly constrained from acting. Adults' reaction times reliably reflected the agent's beliefs only when the agent was free to act on the ball and not when the agent was visibly constrained from acting. Furthermore, it was the agent's constrained action capabilities, rather than any perceptual novelty, that determined whether adult observers' reaction times reliably reflected the agent's beliefs. These findings signal that our motor system may underpin more of social cognition than previously imagined, and, in particular, that motor representations may underpin automatic false-belief tracking.

Anticipatory looking on mindreading tasks can indicate our expectation of an agent's action. The challenge is that social situations are often more complex, involving instances where we need to track an agent's false belief to successfully identify the outcome to which an action is directed. If motor processes can guide how action goals are understood, it is conceivable— where that kind of goal ascription occurs in false-belief tasks— for motor representations to account for someone's belief-like state. Testing adults (N = 42) in a real-time interactive helping scenario, we discovered that participants' early mediolateral motor activity (leftwards– rightwards leaning on balance board) foreshadowed the agent's belief-based action preparation. These results suggest fast belief-tracking can modulate motor representations generated in the course of one's interaction with an agent. While adults' leaning, and anticipatory looking, revealed the contribution of fast false-belief tracking, participants did not correct the agent's mistake in their final helping action. These discoveries suggest that adults may not necessarily use another's belief during overt social interaction or find reflecting on another's belief as being normatively relevant to one's own choice of action. Our interactive task design offers a promising way to investigate how motor and mindreading processes may be variously integrated.

Joint actions often require agents to track others’ actions while planning and executing physically incongruent actions of their own. Previous research has indicated that this can lead to visuomotor interference effects when it occurs outside of joint action. How is this avoided or overcome in joint actions? We hypothesized that when joint action partners represent their actions as interrelated components of a plan to bring about a joint action goal, each partner’s movements need not be represented in relation to distinct, incongruent proximal goals. Instead they can be represented in relation to a single proximal goal – especially if the movements are, or appear to be, mechanically linked to a more distal joint action goal. To test this, we implemented a paradigm in which participants produced finger movements that were either congruent or incongruent with those of a virtual partner, and either with or without a joint action goal (the joint flipping of a switch, which turned on two light bulbs). Our findings provide partial support for the hypothesis that visuomotor interference effects can be reduced when two physically incongruent actions are represented as mechanically interdependent contributions to a joint action goal.

Sensitivity to others’ actions is essential for social animals like humans and a fundamental requirement for any kind of social cognition. Unsurprisingly, it is present in humans from early in the first year of life. But what processes underpin infants’ sensitivity to others’ actions? Any attempt to answer this question must solve twin puzzles about the development of goal tracking. Why does some, but not all, of infants’ goal tracking appear to be limited by their abilities to represent the observed action motorically at the time it occurs? And why does their sensitivity to action sometimes manifest itself differently in dishabituation, pupil dilation and anticipatory looking? Solving these twin puzzles is critical for understanding humans’ earliest sensitivity to others’ actions. After introducing the puzzles, this paper argues that solving them may require identifying multiple, distinct processes for tracking the targets and goals of actions.

Few things matter more than the mental states of those nearby. Their ignorance defines limits on cooperation and presents opportunities to exploit in competition. What others feel, see and know can also provide information about events otherwise beyond your ken. It’s no surprise, then, that abilities to track others’ mental states are widespread. Many animals, including scrub jays, ravens, goats, dogs, ring-tailed lemurs, monkeys and chimpanzees, reliably vary their actions in ways that are appropriate given facts about another’s mental states. What underpins such abilities to track others’ mental states?

What enables individuals to act together? Recent discoveries suggest that a variety of mechanisms are involved. But something fundamental is yet to be investigated. In joint action, agents represent a collective goal, or so it is often assumed. But how, if at all, are collective goals represented in joint action and how do such representations impact performance? To investigate this question we adapted a bimanual paradigm, the circle-line drawing paradigm, to contrast two agents acting in parallel with two agents performing a joint action. Participants were required to draw lines or circles while observing circles or lines being drawn. The findings indicate that interpersonal motor coupling may occur in joint but not parallel action. This suggests that participants in joint actions can represent collective goals motorically.

Motor representations live a kind of double life. Although paradigmatically involved in performing actions, they also occur when merely observing others act and sometimes influence thoughts about the goals of observed actions. Further, these influences are content-respecting: what you think about an action sometimes depends in part on how that action is represented motorically in you. The existence of such content-respecting influences is puzzling. After all, motor representations do not feature alongside beliefs or intentions in reasoning about action; indeed, thoughts are inferentially isolated from motor representations. So how could motor representations have content-respecting influences on thoughts? Our aim is to solve this puzzle. In so doing, we shall provide the basis for an account of how experience links the motoric with thought. Such an account matters for understanding how humans think about action: in some cases, we have reasons for thoughts about actions that we would not have if we were unable to represent those actions motorically

It is normally assumed that there is only one kind of purposive action. This article argues that there are two kinds of purposive action, which require different models of explanation. One kind of action is done without awareness of reasons; another kind of action is done because the agent is aware of reasons for that action. The argument starts by noting that philosophers disagree about what explains action. Some claim that actions are explained by impersonal facts, such as facts about how things should be or have been historically (e.g. Millikan, Stout). Others claim that actions are explained by mental states, such as beliefs and desires (e.g. Davidson, Velleman). These philosophers are usually regarded as offering conflicting accounts of one thing. However, they are best understood as giving accounts of different models of action-explanation. Neither model fits every case, so there are at least two kinds of purposive action.

Are there distinct roles for intention and motor representation in explaining the purposiveness of action? Standard accounts of action assign a role to intention but are silent on motor representation. The temptation is to suppose that nothing need be said here because motor representation is either only an enabling condition for purposive action or else merely a variety of intention. This paper provides reasons for resisting that temptation. Some motor representations, like intentions, coordinate actions in virtue of representing outcomes; but, unlike intentions, motor representations cannot feature as premises or conclusions in practical reasoning. This implies that motor representation has a distinctive role in explaining the purposiveness of action. It also gives rise to a problem: were the roles of intention and motor representation entirely independent, this would impair effective action. It is therefore necessary to explain how intentions interlock with motor representations. The solution, we argue, is to recognise that the contents of intentions can be partially determined by the contents of motor representations. Understanding this content-determining relation enables better understanding how intentions relate to actions.