Contributed by: Hanne De Jaegher, Ezequiel Di Paolo, Tom Froese and Steve Torrance, University of Sussex

Introduction
In this Briefing, we outline an enactive approach to social cognition that is based on a strong focus on the interaction process. Before doing so, we recap on traditional approaches to social cognition and discuss problems they face, the main one being their methodological individualism. Finally, we outline an alternative that goes by the name of participatory sense-making.

Traditionally, accounts of social cognition are concerned with the question "how do people understand each other?" In order to solve this problem, individual mechanisms are generally proposed. They are usually posited in the head, for instance a theory of mind or a simulation mechanism. The assumption behind traditional approaches is that the problem of social cognition is about individuals facing each other across an epistemic gap, puzzling over each other’s behaviour behind which an invisible mind lurks, trying to read that mind from the behaviours, and then finding ways to respond to it or deal with it. This starting point has been criticised. Researchers of embodiment have proposed that we should not search for the mechanisms of social understanding solely in the brains of individuals, but in the whole body. Understanding each other involves the whole moving, expressive, perceptive, emotional body (see for instance Gallagher 2001). They also question the idea that understanding others consists in predicting and explaining their behaviour.

But our social trafic remains troublesome to understand. How we understand each other is only one small aspect of the whole gamut of intersubjectivity. In our engagements with other subjects we love, we fight, we laugh, we trust, we have conflicts, we negotiate, we collaborate, we teach, we imitate, we build and break friendships, we learn, we recognise others at many different levels and in many different ways, we compete, we sympathise, we provoke, we dare, we tell and make up stories, and so on. Traditional approaches would have it that understanding each other is at the basis of all this. But what if it isn’t? Maybe understanding each other is a rather specific skill among the many that make up our intersubjectivity, the precondition, perhaps, of some aspects of the above activities, but not of all.

Traditional approaches to social cognition are theoretically and methodologically individualistic. Individuals understand others through individual processes, either of inference or of simulation. When an agent is able to explain and predict an other’s behaviour, he has 'social' cognition. In accordance with this, the methods to investigate social understanding have focused on proposing and measuring individual mechanisms, typically in the brain.

Problems
Individualistic approaches miss out several crucial aspects of what it means to be a social agent. Social cognition is reduced to the task of figuring out an other’s behaviour – a kind of Rear Window approach to social skill (De Jaegher & Di Paolo, 2007). Accordingly we deal with others much like we deal with scientific problems. Social cognition on this account is different from non-social problem solving merely in degree, not in quality. Engaging with others plays no role.

Participatory sense-making
In contrast with these approaches, an enactive account promises to deal with the wide scope of intersubjectivity. The starting point of its investigation is the process of interacting. The interest is in finding out the mechanism of this process (how does it happen?), and to understand how it shapes interactors, how it is shaped by interactors and the interplay between these two levels. Interactions range from brief encounters to long-term relationships (interactional histories). Emotionally, they can leave participants cold, or can change their life forever. The contexts in which they take place can have more or less of an impact on what participants do and feel. The five central concepts of enactive cognitive science – embodiment, experience, emergence, autonomy and sense-making (Thompson 2005; Di Paolo, Rohde, De Jaegher, 2008) – play a central role in the enactive account of social cognition, but for reasons of brevity, we focus here on the latter two, autonomy and sense-making.

In enactive terms, an autonomous system is a self-sustaining network of processes under precarious conditions (Di Paolo, 2005, Di Paolo, Rohde and De Jaegher 2008; Moreno and Etxeberria 2005; Thompson 2007; Varela 1979, 1997). Such an autonomous system (the paradigmatic case being a living organism) may establish a regulated coupling with its world so that it adaptively follows the norms established by its own self-conservation. In doing so, it is able to distinguish different forms of coupling in terms of value or sense. We call this process sense-making. This relation is at the basis of all forms of cognitive engagement from the simplest bacteria onwards.

In order to put these two concepts, autonomy and sense-making, to work towards a theory of social cognition, we make use of the concept of coordination. Coordination (the non-accidental correlation between the behaviours of two or more systems that are in sustained coupling, or have been coupled in the past, or have been coupled to another, common, system) is a ubiquitous phenomenon in physical and biological systems. Examples range from the synchronization of pendulum clocks to the group flashing of fireflies in Southeast Asia (Winfree, 2001; Buck and Buck, 1976). These examples are merely indicators of the myriad of systems that coordinate when coupled collectively that have been heavily studied in physics, mathematical biology and dynamical approaches to cognition (e.g. Kelso 1995; Kuramoto 1984; Port and van Gelder 1995; Winfree 2001).

In social engagement, coordination not only is a common phenomenon (Jaffe and Feldstein 1970; Kendon 1990), it is often hard to avoid. For instance, when asking pairs of subjects to avoid synchronous oscillations while swinging a pendulum with their arms, Schmidt and O’Brien (1997) found that their oscillations were independent (uncoordinated) when not looking at each other, but presented strong tendency to phase-lock when they were allowed to look at each other. When coordination is observed we need not postulate dedicated individual mechanisms that sustain it, but rather, in general, it is a phenomenon to be expected under a variety of conditions if the systems possess broadly similar properties.

The concept of coordination helps us to understand the social interaction as an ongoing process. Patterns of coordination can directly influence the continuing disposition of the individuals involved to sustain or modify their encounter. In this way, what arises in the process of coordination can have the consequence of steering the encounter or facilitating its continuation. And the particular unravelling of these dynamics itself influences what kinds of coordination are more likely to happen. When this double influence is in place (from the coordination onto the unfolding of the encounter and from the dynamics of the encounter onto the likelihood to coordinate) we say we are in the presence of a social interaction. This emerging level is sustained and identifiable as long as the processes described (or some external factor) do not terminate it. Individuals co-emerge as interactors with the interaction. This brings us to the further requirement for calling an interaction properly social. Not only must the process itself enjoy a temporary form of autonomy, but the autonomy of the individuals as interactors must also not be broken (even though the interaction may enhance or diminish the scope of individual autonomy). If this were not so, if the autonomy of one of the interactors were destroyed, the process would reduce to the cognitive engagement of the remaining agent with his non-social world. The 'other' would simply become a tool, an object, or a problem for his individual cognition (such a situation epitomises what we have diagnosed traditional perspectives on social cognition as suffering from: namely, the lack of a properly social level).

The problem of social understanding is therefore the problem of a relation between different levels of autonomy and the sense-making of the interactors involved. As coordination is manifested in movements and movements and actions are the tools of all sense-making activity, we should expect that the interactional engagement, through patterns of coordination (including breakdowns and recoveries) modulates the sense-making of the interactors. We have termed this phenomenon participatory sense-making, as it describes a full spectrum of possibilities related to the level of symmetry and involvement of the interactors and how their sense-making is modulated. Successful social understanding, therefore, relates to the degree to which individual intentions (pre-existing or shaped during interaction) coordinate as the interaction process unfolds. Examples go from cases of mild participation, such as orientation of the sense-making of another, to joint sense-making and co-action (as in the simple act of giving). The focus on the interaction not only provides us with measurable mechanisms beyond the individual in order to track how sense-making is modulated socially, it also shows that to "understand" one another is a phenomenon with a multiplicity of degrees, hard to reduce to explicit mental inferences or simulations in an individual’s head.

Open issues
The enactive proposal advances a non-invidualistic framework with a definition of the social. It is, of course, a proposal that still leaves many questions open. In particular, working out the practical and empirical consequences of this proposal is an ongoing task. Recent experimental work has started to show the degree to which coordination underlies complex social phenomena such as recognizing another agent in interaction (Auvray, et al. 2008; Di Paolo, Rohde, Iizuka, 2007). More input is needed to develop the concept of "participatory sense-making" along empirical, modelling, theoretical and ethical lines. Eventually, this idea should be compatible with 'macro' social phenomena, like language and patterns of cultural reproduction as well with developmental explanations of individual and social cognition. What this approach does ensure, in contrast to non-interactive proposals, is an explicit two-way link between individual and social processes, leaving open the possibility for individual cognitive skills to have dual or even purely social developmental origins. This is a strictly closed avenue for approaches that are not properly interactive, be they embodied or not.

Workshop
Between August 30th and September 1st, 2008, the first Workshop on Enactive Approaches to Social Cognition was held in Battle, UK. In it several themes around embodied, non-individualistic approaches to social cognition were discussed and several challenges identified.

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