Thursday, October 11, 2007

Simulation and Stances I: The Physical Stance and The Design Stance

What can the theory of embodied categorization tell us about how the intentional stance works? Dan Dennett (1987) speculates that the combinatorial, generative properties of language/the language of thought play a crucial role in our attempts to predict the behaviors of physical, designed, and intentional systems.
Combining data from various areas of research, Poirier et al. (2005), on the other hand, try to account for some aspects of these stances as internal simulations of possible external states.

The Physical Stance

Systems that are able to categorize physical systems, that is, those able to adopt the ‘physical stance’ or use ‘folk physics’, seem to do so by simulating geometrical relationships. (Poirier et al. 2005). MetaToto, for example, is a robot able to build a map of its environment from sensory input, and whose behavior is guided by simulations of movement in his internal map. Thus, the robot is able to categorize physical features, e.g. a wall, not by hitting it but by simulating it (Poirier et al. 2005 757f.; Stein 1994).
People also seem to make physical inferences either by acting on objects (similar to the “we off-load cognitive work into the environment”-view I described briefly here), or by simulating actions and visuomotor experience internally (opposed to simply engaging in mental imagery, where crucial aspects of action-oriented simulation, and dynamics like gravity and other physical, ‘abstract’ forces seem to be missing) (Schwartz and Black 1999).

The Design Stance

Systems able to categorize functional categories, i.e. those able to adopt the ‘design stance’, ‘folk biology’, or mechanics, simulate features of animals or artifacts. (Poirier et al. 2005: 758). According to Hegarty (2004), design inferences work via the ad hoc simulation of ‘abstract’ functional features in a spatial dimension, which can, but not necessarily has to, be complemented by visual simulation.
Of course, as complexity rises, Dan Dennett might be right in assuming a role for language here.
An interesting question concerns how behavior-reading works in other primates. Do they adopt the ‘design stance’, that is, do they simulate functional features in order to predict behavior, e.g. associate certain behavioral/gestural/facial/phonetic patterns as ‘do not come near me’, and others as ‘safe to approach’, etc. -or “Does the chimpanzee have a theory of mind?” (Premack & Woodruff 1978).
Poirier et al. support the idea that other primates do not have a Theory of Mind, that they are not able to model the “’action level’, a rather detailed and linear specification of sequential acts”, but only the “’program level’, a broader description of subroutine structure and the hierarchical layout of a behavioural ‘program’” (Byrne and Russon 1998).
Whereas the action level invokes mental, unobservable, ‘intentional’ concepts, behavior-reading only invokes functional categories such as movement. The reason for this inability to adopt the ‘intentional stance’ may be that primates generally lack the concept of unobservable causes and thus are not able to
“posit hidden mental representations, assessable from the intentional stance.” (Poirier et al. 2005: 758, Povinelli 2000).
The evolution of such a concept may have enabled humans to have a ‘real’ Theory of Mind, and subsequently may have influenced our engagements of the physical stance and the design stance (Herrmann et al. 2007).

Next week I will write about how the intentional stance might work, given what we know about embodiment and simulation.


Byrne, Richard W and Anne E. Russon. 1998. “Learning by Imitation: a Hierarchical Approach.” Behavioral and Brain Sciences 21: 667-684

Dennett, Daniel C. 1987. The Intentional Stance. Cambridge, MA: Bradford Books.

Herrmann, Esther, Josep Call, María Victoria Hernández-Lloreda, Brian Hare, and Michael Tomasello. 2007. “Humans Have Evolved Specialized Skills of Social Cognition: The Cultural Intelligence Hypothesis.” Science 317: 1360-1365.

Hegarty, Mary.2004.“Mechanical Reasoning by Mental Simulation.” Trends in Cognitive Sciences 8: 280-285.

Poirier, Pierre, Benoit Hardy-Vallée and Jean-Frédéric Depasquale. 2005. “Embodied Categorization.” Handbook of Categorization in Cognitive Science. Eds. Henri Cohen and Claire Lefebvre. Amsterdam: Elsevier.

Premack, David Guy and G. Woodruff. (1978). "Does the chimpanzee have a theory of mind?" Behavioral and Brain Sciences 1: 515-526.

Povinellim Daniel J. 2000. Folk Physics for Apes: The Chimpanzee's Theory of How the World Works. Oxford: OUP.

Schwartz, Daniel L. and Tamara Black. 1999. “Inferences through imagined actions: Knowing by simulated doing.” Journal of Experimental Psychology. Learning, Memory, and Cognition. 25.1: 116-136.

Stein, Lynn Andrea. 1994. “Imagination and situated cognition.” Journal of Experimental and Theoretical Intelligence 5: 393-407.

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