1. Is joint action necessarily based on shared intention?
Nicolas Lindner & Gottfried Vosgerau
Department of Philosophy - Heinrich-Heine-Universität Düsseldorf
KogWis2014: How Language and Behavior Constitute Cognition Tübingen
So, if you heard Natalie Sebanz great plenary talk on Monday, you might remember that she willingly left two puzzle pieces out of her picture of joint action. Shared intenions and Social Cognition – and these are basically the two main aspects I will be talking about today. The title of my talk today is „Is joint action necessarily based on shared intention“. In this talk I want to invesitigate whether a leading account of collective intentionality by Michael Bratman succeeds in explaining all varieties of joint action sufficiently.

2. Acting together comes in many forms
Acting together comes in many forms. From spontaneous and simple examples like TAKING A WALK TOGETHER..

3. ..to more complex and coordinated ones like DANCING A TANGO..

4. ..to highly sophisticated actions with many participants like A SYMPHONIC ORCHESTRA PLAYING A CLASSICAL PIECE OF MUSIC:

5. …and many, many more! …

6. There are also early and basic forms that are widely regarded as joint action and occur at the beginning of life – a child playing with an adult…

7. Or together with her peers..

8. Those kinds of early joint action have recently become the focus of attention for theses that regard cooperation as the cradle of human cognitive development. First and foremost, this line of thought has been advocated by Michael Tomasello and colleagues. Their idea is summed up in the following quote, which is the first line of his influential 2005 paper. Here he writes, and I quote:
“We propose that the crucial difference between human cognition and that of other species is the ability to participate with others in collaborative activities with shared goals and intentions: shared intentionality.”
(Tomasello et al. 2005)

9. Coming Attractions Bratman‘s Account of Shared Intention
Criticisms of Bratman‘s Account and Children‘s Joint Action
A New Approach – Acquiring the Concept of Intention
Summary
With regard to a philosophical account of joint action Tomasello mostly draws on Bratman’s account of shared intention – as many accounts of JA in cognitive science. So, this lead us to the following procedure in our talk. First of all, I will give a brief introduction to shared intention. Then, I will present criticisms regarding the explanatory scope of this account regarding children’s joint action. In the next part, I will present our original account of children’s joint action and –in the end- I will wrap everything up.

10. Bratman‘s Account of Shared Intention (SI)
Bratman proposes a
Reductive, functionalist, constructivist account of SI
SI construed of interrelated individual intentions / attitudes of the participants
Small-scale activities
Only a pair of participants
Non-asymmetric authority relations
Follows a two-fold strategy
Characterising the role of shared intention
Giving a substantial account of / sufficient conditions for SI

11. The Role of Shared Intention
Three interrelated jobs:
Help coordinate our intentional actions
E.g. Scrape paint off before, not after, new paint is applied
Help coordinate our planning
E.g. Check whether you get the brushes when I plan on getting the paint
Structure relevant bargaining
E.g. Bargaining when conflicts about who scrapes and who paints occur
Doing these jobs is a necessary condition for any construction of SI

12. Sufficient Conditions for Shared Intention
We intend to J if and only if
(a) I intend that we J and (b) you intend that we J
I intend that we J in accordance with and because of 1a, 1b, and meshing subplans of 1a and 1b; you intend that we J in accordance with and because of 1a, 1b, and meshing subplans of 1a and 1b.
1 and 2 are common knowledge between us.
(Bratman 1993)

13. The Common Knowledge (CK) Condition
Bratman often uses a rather unanalysed notion of CK:
“[…]in shared intention the fact that each has the relevant attitudes is itself out in the open, is public” (Bratman 1993)
“In SCA the fact that there is this mutually uncoerced system of intentions will be in the public domain.” (Bratman 1992)
CK in Shared Agency: Mutual knowledge of the others‘ intentions plus knowledge of the others‘ knowledge
„[…] it is common knowledge among A and B that p just when (a) A knows that p, (b) B knows that p, (c) A knows that B knows that p, (d) B knows that A knows that p, (e) A is in an epistemic position to know that (d), (f) B is an epistemic position to know that (c), and so on.“ (Bratman 2014)
Bratman: unanalysed notion of common knowledge – a bit metaphorical. Only ‘epistemic position’ – not what participants explicitly know! CK about intention&belief, not vast deep of others’ mind. No CK of shared intention, because no circularity wanted

14. The Cognitive Basis for Common Knowledge
Ability to form beliefs
Ability to form beliefs about beliefs
Mental state attribution (oneself and others)
Recursive mindreading
Robust theory of mind!

15. Is SI Too Demanding?
Criticisms stating SI is cognitively too demanding (Tollefsen 2005, Pacherie 2011)
Robust T.o.M. not developed before the age of four (false-belief task)
Children engage in joint action much earlier
Si cannot account for children’s joint action
Problems of these criticisms:
Controversial empirical claims
Bratman’s substantial account aims at sufficient conditions
“Constructivism aims at sufficient conditions for shared intention. It allows for the possibility that there are multiple constructions, […] the best thing to say, in the end, may be that shared intention is multiply realizable” (Bratman 2009)
Young children engage in different forms of joint action: with adults from around 18 months of age & from the end of 2nd year of life also with peers (Brownell 2011)
Onset of possession of robust T.o.M. (Baillargeon et al. 2010; De Bruin/Newen 2012)
(Early) Understanding of common ground / common knowledge (Carpenter 2009; Liszkowski, Carpenter, & Tomasello 2008; Tomasello & Haberl 2003))
Development of mentalizing and meta-representational abilities

16. Does SI Presuppose What It Should Help Explain?
Butterfill (2012)
Joint action regularly used to explain early development of understanding of minds:
“…the unique aspects of human cognition … were driven by, or even constituted by, social cooperation.” (Moll & Tomasello 2007)
“The motivations and skills for participating in this kind of “we” intentionality are woven into the earliest stages of human ontogeny and underlie young children’s developing ability to participate in the collectivity that is human cognition” (Tomasello et al. 2005)
Ideas on cooperation rest upon Bratman’s construction of SI
Bratman’s “Shared Cooperative Activity” (1992)

17. Roles of SI and Understanding of Other Minds I
Butterfill’s objection focuses on functional roles / necessary conditions for SI
Help coordinate our intentional actions
Help coordinate our planning
Structure relevant bargaining
Coordinating & bargaining doesn’t always require intentions which refer to other intentions
Coordination of intentions often based on a shared background (preferences, habits & conventions)
Bratman’s account of SI builds on Individual planning agency - Planning: coordinate agent’s various activities over quite long intervals of time – practical reasoning&forming intentions, possibly require futher planning & generating hierarchy of plans and subplans
EXAMPLE: Giving a talk in a conference like this

18. Roles of SI and Understanding of Other Minds II
In some cases monitoring or manipulating others’ intentions is required
Novel aims / unusual circumstances / unfamiliar partners
Lack of sufficient background
Joint action of young children involves said aspects
Joint action would presuppose psychological concepts whose development it should explain
Early joint action of children cannot involve Bratman’s SI
According to Tomasello & the likes

19. Is Bratman’s Account Incorrect?
Bratman’s account cannot explain children’s joint action
Other construction won’t do – necessary conditions cannot be met
Problematic for approaches that regard joint action / cooperation as pivotal for development of cognitive / socio-cognitive abilities
Explains joint action of mature cognitive agents
Planning
Future-directed intentions
Stability and rationality of plans (norms)
Deliberation

20. An Alternative Account of Children’s Joint Action
Pictures of children who obviously fail at playing hide and seek. Seemingly, this is so because they cannot abstract from their own perspective. I hope you will see how this is related to our approach in a few seconds…

21. Children’s JA Grounded in Other Abilities
Lack of the concept of a mental state (esp. intentions) produces behaviour that looks like JA
If a child hasn’t learned that a mental state is something that ‘belongs’ to single persons the concept of a mental state is not acquired
She might be able to introspect the content of her own intentions – paraphrased: ‘there is the intention to J’

22. Children’s JA Grounded in Other Abilities
Child hasn’t developed the ability to differentiate between own intentions and those of others
Effect of this lack will result in behaviour that looks like JA
In cases where intentions of child and adults match
Matching might be triggered by aspects of the environment: e.g. pointing gestures, affordances or alignment

23. Empirical Evidence in Favour of Our Account
Acquisition of concepts of mental states depends on the use of mental state terms (Rakoczy, Tomasello and Striano 2006)
Comprehension of mental state language correlates to T.o.M. abilities (Grazani/Ornaghi 2012)
Mental state discourse is related to T.o.M. development, in particular the development of representational models of self / other as distinctive mental agents (Symons 2004)

24. Advantages of Our Account
Specifies how (seemingly) JA might be pivotal to the development of socio-cognitive abilities:
JA-like scenarios create environment that helps children to gradually learn that intentions can differ between individuals
Learning phase results in acquisition of the concept of a mental state
Learning of a T.o.M. starts with acquisition of a concept of a mental state
This can be best acquired in (seemingly) JA scenarios, in which children directly experience effects of differing mental states (intentions / beliefs)

25. Summary
Bratman’s account of SI not suited to explain early (seemingly) JA of children if it is pivotal for development of socio-cognitive abilities
Accurately describes JA of cognitively mature agents (planning and deliberation)
Our approach takes pivotal role of JA for socio-cognitive development into account
Shows how learning phase of early forms of acting together fosters acquisition of mental state concepts
Once these concepts are acquired, a T.o.M. can be learned and JA involving SI is possible

26. References
Baillargeon, R., Scott, R. M., & He, Z. (2010). False-belief understanding in infants. Trends in cognitive sciences, 14(3), 110–118. doi: /j.tics
Bratman, M. (1992). Shared Cooperative Activity. Philosophical Review, 101(2), 327–341.
Bratman, M. (1993). Shared Intention. Ethics, 104(1), 97–113.
Bratman, M. (2009). Shared Agency. In Philosophy of the Social Sciences: Philosophical Theory and Scientific Practice. Cambridge University Press.
Brownell, C. A. (2011). Early Developments in Joint Action. Review of philosophy and psychology, 2(2), 193–211. doi: /s
Butterfill, S. (2012). Joint Action and Development. The Philosophical Quarterly, 62(246), 23–47. doi: /j x
Carpenter, M. (2009). Just How Joint Is Joint Action in Infancy? Topics in Cognitive Science, 1(2), 380–392. doi: /j x
De Bruin, L. C., & Newen, A. (2012). An association account of false belief understanding. Cognition, 123(2), 240–259. doi: /j.cognition
Grazzani, I., & Ornaghi, V. (2012). How do use and comprehension of mental-state language relate to theory of mind in middle childhood? Cognitive Development, 27(2), 99–111. doi: /j.cogdev
Liszkowski, U., Carpenter, M., & Tomasello, M. (2008). Twelve-month-olds communicate helpfully and appropriately for knowledgeable and ignorant partners. Cognition, 108(3), 732–739. doi: /j.cognition
Moll, H., & Tomasello, M. (2007). Cooperation and human cognition: the Vygotskian intelligence hypothesis. Philosophical Transactions of the Royal Society B: Biological Sciences, 362(1480), 639–648. doi: /rstb
Pacherie, E. (2011). Framing Joint Action. Review of Philosophy and Psychology, 2(2), 173–192.
Rakoczy, H., Tomasello, M., & Striano, T. (2006). The role of experience and discourse in children’s developing understanding of pretend play actions. British Journal of Developmental Psychology, 24(2), 305–335. doi: / X36001
Symons, D. K. (2004). Mental state discourse, theory of mind, and the internalization of self–other understanding. Developmental Review, 24(2), 159–188. doi: /j.dr
Tollefsen, D. (2005). Let’s Pretend! Children and Joint Action. Philosophy of the Social Sciences, 35(1), 75–97. doi: /
Tomasello, M., Carpenter, M., Call, J., Behne, T., & Moll, H. (2005). Understanding and Sharing Intentions: The Origins of Cultural Cognition. Behavioral and Brain Sciences, 28(5), 675–691.
Tomasello, M., & Haberl, K. (2003). Understanding attention: 12- and 18-month-olds know what is new for other persons. Developmental Psychology, 39(5), 906–912. doi: /
Wellman, H. M., Cross, D., & Watson, J. (2001). Meta-Analysis of Theory-of-Mind Development: The Truth about False Belief. Child Development, 72(3), 655–684. doi: /