Keyboard Shortcuts?f

×
  • Next step
  • Previous step
  • Skip this slide
  • Previous slide
  • mShow slide thumbnails
  • nShow notes
  • hShow handout latex source
  • NShow talk notes latex source

Click here and press the right key for the next slide.

(This may not work on mobile or ipad. You can try using chrome or firefox, but even that may fail. Sorry.)

also ...

Press the left key to go backwards (or swipe right)

Press n to toggle whether notes are shown (or add '?notes' to the url before the #)

Press m or double tap to slide thumbnails (menu)

Press ? at any time to show the keyboard shortcuts

 

Pacherie’s Objection to Bratman on Shared Intention

problem of action problem of joint action we don't need shared intention we do need shared intention Bratman's planning theory Pacherie's team reason- ing theory ??? } } decision theory game theory limits -- hi-lo, prsnr's dlmma team reasoning

‘I am skeptical that all intentional joint actions require the sophistication in ascribing propositional attitudes that Bratman’s account appears to demand.

To motivate this skepticism, I’ll turn to [...] empirical evidence that young children engage in what appears to be intentional joint action despite lacking this conceptual sophistication.’

(Pacherie, 2013, p. 2)

What is this objection and what is the evidence for it?

1. Bratman’s account requires sophistication in ascribing propositional attitudes coordinating planning.

2. There is an age at which children engage in joint action

3. while lacking this sophistication.

∴ Not all joint action involves the shared intentions Bratman characterises.

What is shared intention?

Functional characterisation:

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

Constraint:

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

Substantial account:

We have a shared intention that we J if

‘1. (a) I intend that we J and (b) you intend that we J

‘2. I intend that we J in accordance with and because of la, lb, and meshing subplans of la and lb; you intend [likewise] …

‘3. 1 and 2 are common knowledge between us’

(Bratman 1993: View 4)

Note that the conditions require not just that we intend the joint action, but that we intend it because of each other's intentions, where this is common knowledge.
So we need not just intentions about intentions ...
... also you need to know things about my knowledge of your intentions concerning my intentions.
This indicates that, in general, having shared intentions requires mindreading at close to (or perhaps just beyond) the limits of most adult humans' abilities. Bratman's account of shared intention is an example where reciprocity is modeled as higher-order escalation.
Objection: Meeting the sufficient conditions for joint action given by Bratman’s account could not significantly \textit{explain} the development of an understanding of minds because it already \textit{presupposes} too much sophistication in the use of psychological concepts.
And this is a problem for us ...

Functional characterisation:

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

Substantial account:

We have a shared intention that we J if

‘1. (a) I intend that we J and (b) you intend that we J

‘2. I intend that we J in accordance with and because of la, lb, and meshing subplans of la and lb; you intend [likewise] …

‘3. 1 and 2 are common knowledge between us’

(Bratman 1993: View 4)

Note that these conditions are offered as sufficient but not necessary. (Bratman originally claimed that they were necessary and sufficient, but nothing in the construction rules out alternative realisations of the functional characterisation of shared intention.)
As it stands, then, this objection does not establish much. It concerns conditions imposed by the substantial account of shared intention which are sufficient but not necessary conditions. The substantial account is supposed to characterise one—perhaps one among many—ways in which the functional role of shared intentions can be realised. So the objection serves only to raise a question.
\textbf{Are there in fact alternative sufficient conditions for shared intention, conditions that can be met without already having abilities to use psychological concepts whose development was supposed to be explained by joint action?}
The answer to this question is not entirely straightforward. We must begin with the functional roles of shared intention, for these provide necessary conditions. One of the roles of shared intentions is to coordinate planning. What does coordinating planning involve? Intuitively the idea is that just as individual intentions serve to coordinate an individual’s planning over time, so shared intentions coordinate planning between agents. (I use the terms ‘individual intention’ and ‘individual goal’ to refer to intentions and goals explanatory of individual actions; an ‘individual action’ is an action performed by just one agent such as that described by the sentence ‘Ayesha repaired the puncture all by herself’.) A second role for shared intentions is to structure bargaining concerning plans. To understand these roles it is essential to understand what ‘planning’ means in this context. The term ‘planning’ is sometimes used quite broadly to encompass processes involved in low-level control over the execution of sequences of movements, as is often required for manipulating objects manually, as well as processes controlling the movements of a limb on a single trajectory. In Bratman’s account and this paper, the term ‘planning’ is used in a narrower sense. Planning in this narrow sense exists to coordinate an agent’s various activities over relatively long intervals of time; it involves practical reasoning and forming intentions which may themselves require further planning, generating a hierachy of plans and subplans. Paradigm cases include planning a birthday party or planning to move house.
Given the functional roles of shared intention, when (if ever) must the states which realise shared intentions include intentions about others’ intentions? Coordinating plans with others does not seem always or in principle to require specific intentions about others’ intentions. It is plausible that in everyday life some of our plans are coordinated largely thanks to a background of shared preferences, habits and conventions. Consider, for example, people who often meet in a set place at a fixed time of day to discuss research over lunch. These people can coordinate their lunch plans merely by setting a date and following established routine; providing nothing unexpected happens, they seem not to need intentions about each other’s intentions. Within limits, then, coordinating plans may not always require intentions about intentions. The same may hold for structuring bargaining. But when the background of shared preferences, habits and conventions is not sufficient to ensure that our plans will be coordinated, it is necessary to monitor or manipulate others’ plans. And since intentions are the basic elements of plans (in the special sense of ‘plan’ in terms of which Bratman defined shared intention), this means monitoring or manipulating others’ intentions. The background which makes for effortlessly coordinated planning is absent when our aims are sufficiently novel, when the circumstances sufficiently unusual (as in many emergencies), and when our co-actors are sufficiently unfamiliar. In all of these cases, coordinating plans and structuring bargaining will involve monitoring or manipulating others’ intentions. Now this does not necessarily involve forming intentions about their intentions because, in principle, monitoring and manipulating others’ intentions could (within limits) be achieved by representing states which serve as proxies for intentions rather than by representing intentions as such, much as one can (within limits) monitor and manipulate others’ visual perceptions by representing their lines of sight. But possession of general abilities to monitor and manipulate others’ intentions does require being able to form intentions about others’ intentions.
The question was whether there are sufficient conditions for shared intention which do not presuppose abilities to use psychological concepts whose development is supposed to be explained by joint action. As promised, the answer is not straightforward. In a limited range of cases, coordinating plans and perhaps structuring bargaining does not appear to require insights into other minds. But in other cases, particularly cases involving novel aims or agents unfamiliar with each other, intentions about others’ intentions are generally required.
The main question for this section was whether Bratman’s account captures a notion of joint action suitable for explaining the early development of children’s abilities to think about minds. Some of the joint actions which young children engage in involve novel aims, and some involve unfamiliar partners. So if these joint actions did involve coordinating planning and structuring bargaining, they could not rest on a shared background but would require abilities to form intentions about others’ intentions. It follows that joint action would presuppose much of the sophistication in the use of psychological concepts whose development it was supposed to explain. So given the premise that joint action plays a role in explaining early developments in understanding minds, it cannot be the case that the joint actions children engage in as soon as they engage in any joint actions involve shared intentions as characterised by Bratman.

1. Bratman’s account requires sophistication in ascribing propositional attitudes coordinating planning.

2. There is an age at which children engage in joint action

3. while lacking this sophistication.

∴ Not all joint action involves the shared intentions Bratman characterises.

Warneken and Tomasello, 2007 figure 2 (part)

Trampoline task: first bounce a cube on the trampoline with an experimenter, then experimenter pauses and we measure child’s attempts to re-engage.

Warneken & Tomasello (2007, p. figure 4)

The re-engagement is a powerful signal that children

Infants’ ‘attempts to reactivate the partner in interruption periods indicate that they were aware of the interdependency of actions—that the execution of their own actions was conditional on that of the partner’

Warneken & Tomasello (2007, pp. 290--1)

Infants’ ‘attempts to reactivate the partner in interruption periods indicate that they were aware of the interdependency of actions—that the execution of their own actions was conditional on that of the partner ... these instances might also exemplify a basic understanding of shared intentionality’ (Warneken & Tomasello, 2007, pp. 290--1).
Contrast Warneken and Tomasello with Brownell, who offers a different suggestion.
‘advances in infants’ ability to coordinate their behavior with one another are associated with multiple measures of developing self-other representations. One- and two-year olds’ symbolic representation of self and other in pretend play (e.g., pretending that a doll is feeding itself) was related to the amount of coordinated behavior they produced with a peer on the structured cooperation tasks described above (Brownell and Carriger 1990)’ (Brownell, 2011, p. 206).
‘children who better produced and comprehended language about their own and others’ feelings and actions, and who could refer to themselves and others using personal pronouns likewise monitored their peer’s behavior more often and produced more joint activity with the peer (Brownell et al 2006)’ (Brownell, 2011, p. 206).

1. Bratman’s account requires sophistication in ascribing propositional attitudes coordinating planning.

2. There is an age at which children engage in joint action

3. while lacking this sophistication.

∴ Not all joint action involves the shared intentions Bratman characterises.

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).

Seven-year-old children and adults however, demonstrated evidence for joint action planning. ... While adult participants demonstrated the presence of joint action planning from the very first trials onward, this was not the case for the 7-year-old children who improved their performance across trials.’

(Paulus, 2016, p. 1059)

Paulus et al, 2016 p. 1059

1. Bratman’s account requires sophistication in ascribing propositional attitudes coordinating planning.

2. There is an age at which children engage in joint action

3. while lacking this sophistication.

∴ Not all joint action involves the shared intentions Bratman characterises.

problem of action problem of joint action we don't need shared intention we do need shared intention Bratman's planning theory Pacherie's team reason- ing theory ??? } } decision theory game theory limits -- hi-lo, prsnr's dlmma team reasoning

appendix

more evidence against the prediction

Warneken et al, 2014 figure 1A

‘One child had to insert the turn-tool on the right of the apparatus and then turn so that the metal rod stretching across moved the panel out of the way of the ball. The other person could then insert the push tool on the left, pushing the silver ball into the hole similar to a billiard cue.’ (Warneken, Steinwender, Hamann, & Tomasello, 2014)

Warneken et al, 2014 figure 2

Unidirectional : child A has to select the tool that B doesn’t have.
Bidirectional : child A can select either tool.
‘(a) Unidirectional: The left box will be opened first. Only the left child has a choice. For success, this child has to choose the push tool (lower left: thick handle, long thin top). The partner child has to retrieve the only available turn tool (upper right: thick handle, short thin top).’ (Warneken et al., 2014)

Warneken et al, 2014 figure 3

BU - first bidirectional then unidirectional.
The three year olds are hopeless in all conditions except the bidirectional condition when they have first had the unimanual condition. So there is no forward planning, but there is some evidence that three-year-olds can take into account what another has done.
‘by age 3 children are able to learn, under certain circumstances, to take account of what a partner is doing in a collaborative problem-solving context. By age 5 they are already quite skillful at attending to and even anticipating a partner’s actions’ (Warneken et al., 2014, p. 57).

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

Bratman, 2011 p. 11

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

Prediction: They should be capable, at least in some minimally demanding situations, of coordinating their plans with another’s.

What is shared intention?

Functional characterisation:

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

Constraint:

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

Substantial account:

We have a shared intention that we J if

‘1. (a) I intend that we J and (b) you intend that we J

‘2. I intend that we J in accordance with and because of la, lb, and meshing subplans of la and lb; you intend [likewise] …

‘3. 1 and 2 are common knowledge between us’

(Bratman 1993: View 4)

Note that the conditions require not just that we intend the joint action, but that we intend it because of each other's intentions, where this is common knowledge.
What we have seen suggests that even three-year-olds are probably incapable of meeting this condition ...
... and the idea that they need to know things about another’s intentions about their intentions seems like a bold conjecture indeed.

Mismatch:

Bratman’s account of joint action

vs

1- to 3-year-olds’ joint action abilities

All the evidence has suggests that there is a mismatch between Bratman’s account of joint action and 1- to 3-year-olds’ joint action abilities.
You might object that the experiments mentioned so far all involve tools. Could there be something especially difficult about coordinating planning when tools are involved?

Meyer et al, 2016 figure 1A

Child pass cups to adult who has one had occupied. Adult and child separated by glass window, so have to reach around.
‘Example of a 3-year-old child engaged in the joint-action task with an adult experimenter. (Top) The start of a trial in which the child has a cup and sees the experimenter holding the cup tower in her left hand. The lower two images illustrate the different possible response choices of the child. The child chooses in one trial to pass the cup on the side that is accommodating the other’s actions (middle); and in another trial, on the side that is not accommodating the execution of the partner’s actions (bottom).’ (Meyer, Wel, & Hunnius, 2016)
‘To build one tower, children had to pass five cups. Then the experimenter introduced the next hand puppet with the same procedure. With each change of hand puppet, she switched sides by putting the puppet on her previously free hand ... in total four towers were built, two on each side.’ (Meyer et al., 2016)

Meyer et al, 2016 figure 1B

Meyer et al, 2016 figure 1C

Meyer et al, 2016 figure 2

‘two measures of interest: the initial response choice (i.e. the first trial only) and the continuous response choice (i.e. all trials except the first)’ (Meyer et al., 2016)
‘In their initial response choice, children had to plan ahead without having experienced how their own action would affect their joint- action partner. Thus, the initial response choice reflects whether children proactively planned to accommodate their joint-action partner.’ (Meyer et al., 2016)

Meyer et al, 2016 figure 3

3-year-olds and younger: not good at changing the side they pass the object on to take into account where the other will reach it.
‘children proactively plan their actions in a way that accommodates the actions of their partner early in childhood. By contrast, the flexible adjustment of their action plans to their partner only begins to develop in the fourth and fifth year of life. Notably, even at the age of 5 children only adjusted their action plans to a surprisingly small degree’ (Meyer et al., 2016, p. 8).
I think: the good results on the initial response choice at all ages suggest that some ability to take into account another’s immediate future actions may already be present at 2-and-a-half years of age (although this is not strong evidence).
Note that the success concerns anticipating ACTIONS not antcipating PLANS.

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

Bratman, 2011 p. 11

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

Prediction: They should be capable, at least in some minimally demanding situations, of coordinating their plans with another’s.

Gerson et al, 2016 figure 1B

Subjects: three-year-olds.
Four balls, four egg cups. Yellow balls must go in yellow egg cups, brown balls likewise. One ball is brown and yellow and can go in either colour egg cup. But you only have four egg cups, so you have to put it in whatever egg cup will enable you to place the other three balls correctly.
Experiment: compare performance in an individual condition (child does all) with performance in a joint condition (child alternates with puppet) and a control condition with a machine (not joint action, but similar turn-taking required.)
‘The joint play session consisted of nine trials. In the first, fourth, and seventh trial, Kip let the child place the first (and third) ball and Kip placed the second (multi-colored) and fourth ball. Kip always placed the multi-colored ball in the cup that allowed all forthcoming balls to be placed correctly. In the other six trials, Kip placed the first and third balls and the child placed the second and fourth balls. This ensured that the number of trials for which the child had to plan (by placing the multi-colored ball correctly) was matched across the individual and joint conditions.’ (Gerson, Bekkering, & Hunnius, 2016)

Gerson et al, 2016 figure 3

Results: When acting alone or alternating with a machine, three-year-olds were above chance at selecting the correct egg cup for the two-coloured ball. But in joint action they were not above chance, and their performance was significantly worse than when acting alone.
The results indicate that
‘proactive planning for two individuals, even when they share a common goal, is more difficult than planning ahead solely for oneself’ (Gerson et al., 2016, p. 128).