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\title {Joint Action \\ Lecture 14}
\maketitle
\def \ititle {Lecture 14}
\def \isubtitle {Joint Action}
\begin{center}
{\Large
\textbf{\ititle}: \isubtitle
}
\iemail %
\end{center}
How to go about constructing a theory of phenomena associated with acting together?
Step 1: identify features associated with things commonly taken to be paradigm joint actions in non mechanistic terms, e.g.
- collective goals
- coordination
- cooperation
- contralateral commitments
- ...
Step 2: generate how questions.
Step 3: answer the how questions.
Step 4: determine implications for philosophical approaches to joint action.
Cooperation
\section{Cooperation}
\section{Cooperation}
There are several notions of cooperation.
One is trade-off cooperation.
Although widely ignored, trade-off cooperation matters in the sense
that achieving it is a condition on optimally distributing resources.
An aim for an account of joint action is therefore to explain in virtue of
what two or more agents’ actions can be trade-off cooperative.
My larger aim is to answer a simple question: What enables humans to cooperate?
What enables humans to cooperate?
What enables humans to cooperate?
But before we can answer this question, we first need to fix ideas about cooperative
action.
\section{Two Standard Notions of Cooperation}
1
a ‘cooperator is someone who pays a cost, c, for another individual to receive a benefit, b’
(Nowak 2006, p. 1560).
\citep[p.~1560]{nowak:2006_five}
2
‘[b]y cooperation we mean engaging with others in a mutually beneficial activity’ (Bowles & Gintis 2011, p. 2)
\citep[p.~2]{bowles:2011_cooperative}
This second notion of cooperation has been elaborated by McMahon and others.
I’m tempted to think that the former is merely helping rather than cooperation, but this is not the
consensus in the literature. For example, Michael Tomasello explicitly recognises both definitions.
In his view they capture ‘two basic forms’ of cooperation
‘Cooperation appears in nature in two basic forms’ (Tomasello)
\citep{tomasello:2016_natural}
3
\section{Philosophers’ Notions of Cooperation}
Actions are cooperative when appropriately related to a shared intention (and no deception nor coercion) (~Bratman, 1992; 2015).
\citep{Bratman:1992mi,bratman:2014_book}
Roughly Bratman’s strategy has been followed by a variety of philosophers.
As Cedric Paternotte notes,
‘A definition of cooperation ... typically [has this] structure: a set of individual intentions [with] certain origins and ... certain relations, ... is common knowledge’
(Paternotte 2014, p. 47)
\citep[p.~47]{paternotte:2014_minimal}
There’s an important general difference between the left hand side (definitions 1-2) and the
right hand side.
Left hand side: agnostic about mechanisms. May not even involve anything psychological at all.
This allow us to separating the task of characterising the thing to be explained (cooperative
action) from the task of identifying psychological structures which may explain it (such as a
certain structure of intentions and knowledge, say).
Right hand side: cooperation is not explicitly characterised except in terms of psychological
structures.
Bratman does not separate the thing to be explained (cooperative
action) from the task of identifying psychological structures which may explain it (such as a
certain structure of intentions and knowledge, say).
Instead he introduces shared cooperative activity with examples (see,
for example, Bratman 1992, p. 327) and then characterises it by stating structures of intention
and knowledge sufficient to realise it. Bratman’s approach is shared by some who offer competing
characterisations of cooperation (for example, see Paternotte 2014; Pacherie 2013). In each case,
no notion of cooperation is explicitly characterised except by reference to psychological
structures involving intention and knowledge.
What is it for some actions to be cooperative?
It is for them to be appropriately related to shared intentions
(in the absence of deception, coercion ...).
What enables humans to cooperate?
Their capacities to form, and to act on, shared intentions.
The approach Bratman and other philosophers take involves appealing to the same psychological
structure twice.
If we ask, ‘What is it for actions to be cooperative?’, the answer is given in terms of shared
intention, a particular kind of psychological structure.
And if we ask, ‘What enables humans to cooperate?’, the answer is again given in terms of shared
intention.
Appeal to the same psychological structure in explaining both what it is for actions to be
cooperative and in virtue of what they could be cooperative seems unsatisfactory. If another
philosopher identifies shared intention with a slightly different psychological structure (or family
of these), is she providing a compatible characterisation of a different notion of cooperation or a
competing characterisation of the same notion of cooperation? There appears to be no way to answer
this question on the approach taken by Bratman and other philosophers. And this means that there is
no way, in advance of accepting the proposed theory about shared intention, to understand which
notion of cooperation the theory is supposed to capture.
So if I ask, What is the theory a theory of? it seems that I can only answer this
question by accepting the theory.
Maybe there is nothing wrong with this approach, and maybe it is the best we can do.
But I think we should at least attempt to separate the questions and characterise the thing
to be explained in terms which do not already involve the thing which explains it.
What about the other definitions?
I think there is an important notion of cooperation which neither definition captures.
To explain why, let me introduce you to this couple who are both economists.
They just got married ...
\section{Another Notion of Cooperation}
This couple are both economists.
While married, they do various things together. They buy and sell a house, and they
nurture and educate their children.
When deciding whether and how to do something, each considers only the collective costs of
their actions. Neither is at all concerned with how costly her own, or the other’s,
actions would be.
They are simply concerned to minimise the collective costs involved in achieving various
goals.
Of course, this is not the same thing as paying a cost for the other to benefit.
On the contrary, if one of them can reduce the overall costs involved in their actions
but minimising the effort she herself puts in, thereby requiring the other to do all the
hard work, she will readily do so.
Unfortunately, one day they get divorced.
After their divorce, their attitudes change.
Now each is concerned only to minimise her own costs in acting.
When deciding whether and how to do something, neither is at all concerned with
the collective costs or what it costs the other. They each attempt only to minimise
their own costs in acting.
When one of them can save herself a trivial amount of effort, she will do so even if it
means pushing the other right to her limits.
Even after divorce, the couple do do things together, and they pursue mutually
beneficial activities when these maximise individual gains.
After all, they remain bound together by various legal, moral and prudential obligations.
And they recognise that engaging in mutually beneficial activities will often reduce
the costs for them involved in acting.
They are not at all bitter or vindictive.
They simply do not care about each other’s costs, only their own.
They’re true economists.
| while married | after divorce | |
| [df. 1] pay a cost for the other to benefit? | ✗ | ✗ |
| [df. 2] engage in mutually beneficial activity? | ✓ | ✓ |
So (1) neither definition distinguishes between the actions of the economist couple
before and after their divorce, but (2) their actions while married are, I think,
clearly more cooperative than their actions after their divorce.
This indicates that we need a further notion of cooperation.
my costs
your costs
our costs
Performing actions involves costs.
Typical costs include giving time, putting in effort, taking risks and paying money.
There are three distinct things you might care about: my costs, your costs or
our costs.
You can care about any one of these without caring about the other.
To a first approximation, I think our actions are cooperative to the extent that we each select
with a view to minimising our collective costs.
Three ways of engaging in the
mutually beneficial activity
of
passing a book between us:
I simply grasp it as comfortably as I can.
I grip it so as to reduce the overall awkwardness of our actions.
I grip it so as to make your grip least awkward.
Instances of the type of contrast we have been considering can be found at every scale, from actions
comprising most of a life to a momentary interaction.
For a small-scale contrast, imagine two people moving a sequence of bulky objects from a shelf to a
table.
There are three ways in which we might do this.
For each object, the first person takes it from the shelf and passes it to the second person, who
places it on the table \citep[here we borrow from a discussion by][]{meyer:2013_higher-order}.
[Be careful: Meyer et al don’t consider overall awkwardness; it’s about reducing the awkwardness of
a future event (end-state comfort effect).]
There are two ways the first person could grip each object, one more awkward than the other. The
more awkward grip results in less awkward actions overall. Sometimes the first agent selects this
more awkward grip in part because it results in less awkward actions overall. On other occasions,
the first person selects a grip merely because it results in less awkward actions for herself. It
seems her actions are more cooperative when she minimises the overall awkwardness of both of their
actions than when she minimises the awkwardness of her own actions only.
But this contrast in cooperativeness cannot straightforwardly be captured by either standard notion
of cooperation. Selecting a more awkward grip does benefit the other, but (we stipulate) the grip is
selected to reduce the overall awkwardness of the actions rather than to benefit any individual
agent. And of course in moving an object together, the agents are always performing actions which
bring about a mutual benefit since (by stipulation) both partners want the object to be on the table.
1
a ‘cooperator is someone who pays a cost, c, for another individual to receive a benefit, b’
(Nowak 2006, p. 1560).
2
‘[b]y cooperation we mean engaging with others in a mutually beneficial activity’ (Bowles & Gintis 2011, p. 2)
‘Cooperation appears in nature in two basic forms’ (Tomasello)
3
Actions are cooperative when they are appropriately related to a shared intention and some other conditions are met
(~Bratman, 1992; 2015).
‘A definition of cooperation ... typically [has this] structure: a set of individual intentions [with] certain origins and ... certain relations, ... is common knowledge’
(Paternotte 2014, p. 47)
These three contrast cases each point to the possibility that we need a further notion of
cooperation. We do not take the contrasts to provide a decisive argument for this conclusion, of
course. After all, if an opponent were to insist that the contrasts do not concern cooperation at
all, we know of no argument to convince her otherwise. Despite this limit, reflection on the
contrast cases does at least motivate considering a further notion of cooperation. Ultimately, the
interest of this further notion of cooperation will not rest entirely on the contrasts but also on
its wider usefulness.
Demandingness and well-suitedness
\\ require trade-offs
\\ across multiple actions,
\\ not all of which need be yours.
What is it for some actions to be cooperative?
Demandingness and well-suitedness
The contrasts considered in the previous section motivate introducing a third notion of
cooperation. To this end, let us distinguish two dimensions on which purposive actions can be
evaluated. One dimension concerns how well suited the actions are to bringing about the goal or
goals to which they are directed. In simple cases we can think of this as the probability that the
goal will obtain given that the actions occur. A second dimension on which purposive actions can
be evaluated concerns how demanding the actions are: the effort they require, the risks of harm to
you they involve, the collateral damage they incur, and how unpleasant or wrong they are.
require trade-offs
across multiple actions,
not all of which need be yours.
Acting purposively involves making trade-offs between demandingness and well-suitedness. When
selecting among possible means to a goal, you often have to balance how well suited the means is
against how demanding it is. This balancing is what you are doing in deciding how far to walk
towards the can before attempting to throw the trash into it.
Determining a trade-off for one action may constrain which trade-offs are available for other
actions. For this reason, balancing well suitedness against demandingness often requires taking
into account more than one action. When entirely occupied with getting trash into the can, you
might go right up to it. But when simultaneously responsible for controlling some inquisitive
toddlers, a different trade-off may be appropriate. Often what matters is selecting a pattern of
trade-offs with a good overall balance of demandingness and well-suitedness rather than achieving
the best trade-off for any individual action.
In considering patterns of trade-offs between demandingness and well-suitedness,
individuals sometimes include not just their own actions but also those others will
perform. For example, in passing a book between us, you might grasp it somewhat
awkwardly in order that I can take it in just the way needed
to place it.
Or, to return to the example I started with, when we pass each other in a narrow corridor,
we may each turn our bodies just enough to minimise the overall awkwardness.
We are each aiming to achieve a good pattern of trade-offs between demandingness and
well-suitedness for all of our actions, yours and mine.
Purposive actions are cooperative to the extent that, for each agent, her performing these actions rather than any other actions depends in part on how good an overall pattern of trade-offs between demandingness and well-suitedness can be achieved for all of the actions.
We can characterise a third notion cooperation by appeal to patterns of trade-offs between
demandingness and well-suitedness.
Purposive actions are cooperative to the extent that, for each agent, her
performing these actions rather than any other actions depends in part on how good
an overall pattern of trade-offs between demandingness and well-suitedness can be achieved
for all of the actions.
The more weight agents give to this overall pattern of trade-offs, the more cooperative their
actions.
Purposive actions are cooperative to the extent that, for each agent, her
performing these actions rather than any alternative actions depends in part on
how good an overall pattern of trade-offs between demandingness and well-suitedness can
be achieved for all of the actions.
The more weight agents give to this overall pattern of trade-offs, the more cooperative their actions.
This notion of cooperation is clearly important insofar as optimally distributing
resources in a society requires its members to perform actions which are cooperative
in this sense.
Core idea is very simple: minimise overall costs, so neither my costs nor your costs but our costs.
What’s the relation between this notion and the second notion (engaging in mutually beneficial
activities)? This notion concerns selection of means; the second notion concerns goals (whether
they are collective, or whether their pursuit bring mutual benefits).
What’s the relation between this notion and the third notion of cooperation (the philosophers’)?
I think these notions are orthogonal. I also don’t see why the philosophers aren’t talking about
coordination only, rather than cooperation.
\section{Motor Representation}
A \emph{goal} is an outcome to which an action is directed.
Motor representations represent goals such as the grasping of an egg or the pressing of a switch.
These are outcomes which might, on different occasions, involve very different bodily configurations
and joint displacements (see \citealp{rizzolatti_functional_2010} for a selective review).
Motor representations trigger processes which are planning-like insofar as they involve (a) computing
means from representations of ends; and (b) satisfying relational constraints on actions.
Why motor representation?
Aside: social ontology needs psychology like ontology needs physics.
So far I’ve argued that we can, and probably should, characterise what it is for actions
to be more or less cooperative in a way that doesn’t presuppose anything about the
mechanisms which enable agents to cooperate.
We can, and should, separate the thing to be explained from the thing which explains it.
This is just by way of trying to fix ideas about what cooperative action is.
But as I said at the start,
The question I really want to answer is, What enables humans to cooperate?
What enables humans to cooperate?
So what does enable humans to cooperate?
Separating the thing to be explained from the thing which explains it allows us to
entertain the idea that there may be multiple mechanisms.
And in species such as humans, where cooperation is critical for reproductive success, it
seems plausible that multiple, independent mechanisms could underpin cooperation.
In part: a certain interagential structure of motor representation
In what follows I want develop the claim that, in some cases, it is
a certain interagential structure of motor representation that enables humans to cooperate.
conclusion
In conclusion, ...
Examples and contrast cases
are just not enough
to ground a theory of joint action.
Question
What distinguishes genuine joint actions from parallel but merely individual actions?
How to go about constructing a theory of phenomena associated with acting together?
Step 1: identify features associated with things commonly taken to be paradigm joint actions in non mechanistic terms, e.g.
- collective goals
- coordination
- cooperation
- contralateral commitments
- ...
Step 2: generate how questions.
Step 3: answer the how questions.
Step 4: determine implications for philosophical approaches to joint action.
Separate
the thing to be explained
from
the thing that explains it.