Minimal Models for Acting Together

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Minimal Models for Acting Together

II

minimal models for acting together?

Programme

1. The Leading Account (Bratman’s)

2. Problems for the Leading Account

3. A Minimal Alternative

But first let me explain what joint action is ...

These and other contrasts invite the question, What distinguishes joint actions from things that we do in parallel but merely individually?

shared intention

Lots of philosophers and some psychologists think that all joint actions involve shared intention, and even that characterising joint action is fundamentally a matter of characterising shared intention.

‘I take a collective action to involve a collective [shared] intention.’

(Gilbert, 2006, p. 5)

(Gilbert 2006, p. 5)

‘The sine qua non of collaborative action is a joint goal [shared intention] and a joint commitment’

(Tomasello, 2008, p. 181)

(Tomasello 2008, p. 181)

‘the key property of joint action lies in its internal component [...] in the participants’ having a “collective” or “shared” intention.’

(Alonso, 2009, pp. 444--5)

(Alonso 2009, pp. 444-5)

‘Shared intentionality is the foundation upon which joint action is built.’

(Carpenter, 2009, p. 381)

(Carpenter 2009, p. 381)

?

shared intention

What is shared intention?

‘I will … adopt Bratman’s … influential formulation of joint action … each partner needs to intend to perform the joint action together ‘‘in accordance with and because of meshing subplans’’ (p. 338) and this needs to be common knowledge between the participants.’

(Carpenter, 2009, p. 281)

What is shared intention?

Functional characterisation:

shared intention serves to (a) coordinate activities, (b) coordinate planning and (c) structure bargaining

Constraints:

Inferential integration ... and normative integration (e.g. agglomeration)

In making this idea more precise, Bratman proposes sufficient conditions for us to have a shared intention that we J ...

... the idea is then that an intentional joint action is an action that is appropriately related to a shared intention.

Programme

1. The Leading Account (Bratman’s)

2. Problems for the Leading Account

3. A Minimal Alternative

Hypothesis (Carpenter): One- and two-year-olds have shared intentions as characterised by Bratman.

‘shared intentional agency [i.e. ‘joint action’] consists, at bottom, in interconnected planning’

(Bratman, 2011, p. 11).

Prediction: One- and two-year-olds should be capable, at least in some minimally demanding situations, of coordinating their plans with another’s.

Paulus et al, 2016 figure 1

Task: give the tool to another person, who needs to put the spherical end into the box. (Tip: you need to grasp it by the spherical end and pass it so that the other takes the cube-end; they can then insert it optimally.)

Paulus et al, 2016 figure 2B

‘3- and 5-year-old children do not consider another person’s actions in
their own action planning (while showing action planning when acting
alone on the apparatus). 
(Paulus, 2016, p. 1059)

Hypothesis (Carpenter): One- and two-year-olds have shared intentions as characterised by Bratman.

‘shared intentional agency [i.e. ‘joint action’] consists, at bottom, in interconnected planning’

(Bratman, 2011, p. 11).

Prediction: One- and two-year-olds should be capable, at least in some minimally demanding situations, of coordinating their plans with another’s.

Not just one experiment: all the research I could find paints the same picture.

also adults ...

A \emph{very small scale action} is one that is typically distantly related as a descendent by the means-end relation to the actions which are sometimes described as ‘small scale’ actions, such as playing a sonata, cooking a meal or painting a house (Bratman, 2014, p. 8).

There are very small scale joint actions like playing a chord together in the course of playing a duet, clinking glasses in the course of toasting our success, or plassing a plate between us in the course of doing the washing up together.

Small Scale

Very Small Scale

Playing a piano duet

Playing a chord together

Toasting our success together

Clinking glasses

Washing up together

Passing a plate between us

Philosophers have rarely considered such very small scale joint actions. But at least some such cases seem to involve exercising shared agency no less than larger scale activities like painting a house together.

But very small scale joint actions create a challenge to views like Gilbert’s.

Those views hinge on the roles of intention and practical reasoning.

But in at least some cases, very small scale joint actions are not a consequence of practical reasoning concerning those particular actions, nor need they involve intentions which specify outcomes to which the very small scale joint actions are directed. There is simply no need for practical reasoning, or intention, in many such cases. This is particularly obvious if you think about very small scale joint actions which occur in the context of larger scale activities, such as our playing a chord in the course of playing a piano duet.

Of course, there is no principled bar to having intentions concerning the goals of such very small scale actions (as far as I know), and such intentions may sometimes exist. But in very small scale cases of acting together, intentions and practical reasoning are often superfluous and sometimes absent.

Despite this, these very small scale interactions appear to involve exercises of shared agency no less than small scale activities such as playing a piano duet.

So this also makes pressing the question about limited cognitive resources.

Programme

1. The Leading Account (Bratman’s)

2. Problems for the Leading Account

3. A Minimal Alternative

goal != intention

A goal is an outcome to which an action is directed: the grasping of a mug or the writing of a paper, for example.

Importantly, a goal is not an intention. An intention is a mental state whereas a goal is an outcome, so a state of affairs. And not usually a mental one.

[It’s easy to miss the distinction between goals and intentions, perhaps because in talking about goals you may reveal much about what you intend.]

Just as some injections can be collectively life-saving, so some actions can be collectively directed to a goal. For example, consider this sentence:

‘The goal of their actions is to find a new home.’

This can be interpreted distributively: each of their actions is separately directed to finding a new home. But it can also be interpreted collectively: finding a home is an outcome to which their actions are directed and this is not, or not just, a matter of each of their actions being individually directed to finding a home.

The difference between distributive and collective interpretations is clearly substantial, for on the distributive interpretation the statement can only be true if her life has been saved more than once, whereas the truth of the collective interpretation requires only one life-threatening situation.

Note that collective goals do not plausibly require any kind of intentions or commitments. After all, there is a sense in which some of the actions of swarming bees are directed to finding a nest and this is not, or not just, a matter of each bee’s actions being individually directed to finding a nest. So finding a nest is a collective goal of the bees’ actions.

A collective goal (df):

an outcome to which two or more agents’ actions are directed

where

this is not, or not only,

a matter of each action being directed to that outcome.

let me illustrate ...

There are some actions that we perform

among all their actual and possible consequences,

There are some to which our actions are collectively directed.

A collective goal (df):

an outcome to which two or more agents’ actions are directed

where

this is not, or not only,

a matter of each action being directed to that outcome.

Minimal Joint Action

An event involving two or more agents where the agents’ actions have a collective goal.

Conjecture :
collective goals are represented motorically

Let me explain what this amounts to.

\begin{enumerate} \item There is one outcome which each agent represents motorically, and \item in each agent this representation triggers planning-like processes \item concerning all the agents’ actions, with the result that \item coordination of their actions is facilitated. \end{enumerate}

Garbarini et al, 2014 figure 3 (part)

To test this conjecture, Corrado Sinigaglia and I teamed up with Francesco della Gatta, Francesca Garbarini and Marco Rabuffetti. We adapted a bimanual paradigm, the circle-line drawing paradigm, which has been extensively employed for investigating bimanual interference (Franz et al, 1991).

When people have to simultaneously perform noncongruent movements, such as drawing lines with one hand while drawing circles with the other hand, each movement interferes with the other and line trajectories tend to become ovalized. This “ovalization” has been described as a \textbf{bimanual coupling effect}, suggesting that motor representations for drawing circles can affect motor representations for drawing lines (Garbarini et al. 2012; 2013a; 2015a; 2015b; Garbarini and Pia 2013; Piedimonte et al. 2014).

[repetitive] Suppose a straight line and a circle are being drawn at the same time. The straight line will exhibit ovalization.

This ovalization is not just a consequence of pysiology, for you find much the same ovalization when someone is merely imagining drawing the circle, and in patients with anosognosia for hemiplegia.

Instead, the ovalization is a sign that the goal of drawing the two lines, one straight and the other circular, is being represented motorically.

della Gatta et al, ‘Drawn Together’ Cognition 2017

What happens if you distribute the actions across two people, so that a confederate draws the circles while the participant draws a line?

We contrasted a Parallel Action task with a Joint Action task. These tasks differed only in the instructions given.

ALL CL CONDITIONS

Draw lines.

While doing this, look at the screen in front of you.

PARALLEL

You will see circles.

JOINT

You and Gabriele have the collective goal of drawing lines and circles together in order to produce a single design

If participants were to follow our instructions, their actions would have the collective goal of drawing a circle and a line in the Joint Action task but not in the Parallel Task.

We reasoned: if collective goals can be represented motorically, then the joint action instruction should increase the probability that participants represent the collective goal of drawing a circle and a line. And this should result in greater ovalization of the lines drawn in the Joint Action task than in the Parallel Action task ...

And that was actually what we found.

Our hypothesis is that interpersonal motor coupling may occur when an individual is acting unimanually, providing she is acting jointly with another and not merely acting in parallel. This is because in joint action, but not in parallel action, an individual could represent motorically the collective goal of drawing both a circle and a line even if she is actually only drawing a line. Somewhat as in the case of individual bimanual action, so also in joint action: the motor representations of one hand’s drawing can influence the motor representations of the other hand’s drawing. One difference in joint action, of course, is that the hands belong to different individuals.

della Gatta et al, ‘Drawn Together’ Cognition 2017

more evidence

parallel vs joint tones (Sacheli, Arcangeli, & Paulesu, 2018)

imitation effects with lightbulb (Clarke et al., 2019)

A collective goal (df):

an outcome to which two or more agents’ actions are directed

where

this is not, or not only,

a matter of each action being directed to that outcome.

Minimal Joint Action

An event involving two or more agents where the agents’ actions have a collective goal.

Conjecture :
collective goals are represented motorically

Let me explain what this amounts to.

\begin{enumerate} \item There is one outcome which each agent represents motorically, and \item in each agent this representation triggers planning-like processes \item concerning all the agents’ actions, with the result that \item coordination of their actions is facilitated. \end{enumerate}

A collective goal (df):

an outcome to which two or more agents’ actions are directed

where

this is not, or not only,

a matter of each action being directed to that outcome.

Minimal Joint Action

An event involving two or more agents where the agents’ actions have a collective goal.

Conjecture :
collective goals are represented motorically

Let me explain what this amounts to.

\begin{enumerate} \item There is one outcome which each agent represents motorically, and \item in each agent this representation triggers planning-like processes \item concerning all the agents’ actions, with the result that \item coordination of their actions is facilitated. \end{enumerate}

What’s next

next: link with minimal mindreading?

minimal mindreading’s link with joint action would have been solved, at least partially, if our motor mindreading conjecture had panned out.

next: development of joint action?

next: not just motor representations

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Minimal Models for Acting Together

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