Description : Lecture 1. The Intentional Communication of Great Apes
Ape gestural communication flexible, intentional, but not co-operative (no shared intentionality).
Biol. comm. = any physical or behavioral feature that evolved to influence others
Need equilibrium of costs & benefits for Comm. (C) & Audience (A)
EG: angler fish, duck mating displays
Communicator = behavioral manipulation <=> Audience = information
1.1. Great Apes' Vocalizations and Gestures
Displays = genetically fixed <=> Signals = flexible, voluntary
Vocalizations = displays
Unlearned & inflexibly used
no indiv diff; isolation exps; cross- fostering exps
inflexibly used: particular situations and emotions
do not learn new vocalizations (even w/ with humans)
Goodall: "The production of a sound in the absence of the appropriate emotional state seems to be an almost impossible task for a chimpanzee"
Broadcast to all: audience effects = presence/absence of kin (at best)
e.g., call even when whole group is there (predator, food)
Evolutionarily urgent functions ==> high emotions
e.g., vervet alarm calls: [apes = no referentially specific calls]
A = extract information (learn bird alarms)
C = cause behavior: predator retreats; kin run to safety
Seyfarth & Cheney (2003, p. 168): "Listeners acquire information from signalers who do not, in the human sense, intend to provide it."
Vocal comm. basically same in all mammals (ground squirrels, dolphins)
Gestures = signals
Many genetically fixed postures & facial expressions
But some: less evolutionarily urgent functions ==> relaxed emotions
e.g., play, riding, nursing, begging, grooming
Flexible Use [analogy: tool use]
learned: individual differences; novel (idiosyncratic) gestures, new gestures with humans (see below)
flexibly used: means-ends dissociation
combinations/sequences
ontogenetic ritualization, not imitation
sequence: (i) C does X; (ii) A anticipates by doing Y at int. move.; (iii) C notices this, and just produces int. move.
evidence: group comparisons; experiment
no imitation: gestures = one-way, not shared (¿convention?)
Attention to the attention of the partner
Directed at individual recipients (not broadcast)
much evidence: visual gestures only when A attending
Visual modality: focus on attentional state of partner
A: is it directed to me? C: Is she attending?
Type I: Intention movements: und. others' goals
e.g., arm-raise, touch-side: I want you to do X.
imperative, dyadic (food-beg as exception; object 'offer')
metonymic (no iconic) => function/meaning internal to activity
supposed gorilla examples of iconic
Type II: Attention getters: und. others' perception
to obtain attention on displays: I want you to see me [do X]
e.g., leaf clipping (erection), throw stuff (play face)
function/meaning from display
chimp and gorilla examples of hiding displays
auditory attention getters: only African apes
make noise without emotion
to obtain attention to body part or object: groom, play, food
I want you to see: ¿Gricean claim of attention?
apes do not produce sequence: att-getter + intention-movement
walk around (observations, experiment): esp. Pan
Comparison: ape gestures more cognitively sophisticated (closer to language) than vocalizations => based on und. that others have goals & perceptions
Learned, flexible, novel, creative combinations (vocal = no)
Chosen w/r/t attentional state of the recipient (vocal = no)
and use of attention getters, walking around
More sophisticated in apes than in monkeys (vocal = opposite)
But not conventions => not shared, only one-way (not imitated)
But no pointing or iconic gestures: not even when want something
Not collaborative (no requests for clarification)
1.2. Great Apes and Pointing
Approx. 60-70% of captive chimps point imperatively for humans
to out-of-reach food, w/ persistence, when human looking
- nothing systematic w/ vocalizations (auditory att-getters: yes)
point to tool, so humans can use it to get them food [C&T, '94]
so human can use it for self? (so far = no)
point to where food was hidden many hours before
Kanzi combines pointing with lexigram to specify who
others: bring human to place where she can help; give human locked box for help; put human's hand on pocket => analogy = tool-use
no declarative (sharing) pointing; no informative (helping) pointing
no characterizing gestures; but can be taught ASL signs = imperative
¿What are these points? And why for humans, but not for conspecifics?
conspecifics competitive <=> humans helpful
human evol.: imperative pointing when others become helpful
Comprehending pointing
Apes can follow gaze or pointing gesture to, e.g., food (no inference)
But apes terrible in object choice, w/ food hidden; Why?
kids good at 12-14 mos.
Hare & T competitive object choice experiment
und. goal & perceptions of other (in competition)
make inference about goal of reaching
Herrmann & T => "Don't!" experiment => inference from prohibition
¿ und. indiv. imperatives?
Next Lecture: not missing und. of intentionality [goal, percept, act]
but missing shared intentionality: joint attention, communicative intention (relevance to JAF), cooperative motive to share info.
Sidebar on domestic dogs (and foxes) => skills in obj choice
wolves, undom. foxes => no skills
Rico 'words': frame is always "Fetch!" (natural + trained)
- new experiment w/icons
1.3. Summary: Ape Gestural Communication
Ape gestures => intentional communication: (i) flexible, (ii) audience design
Based on und. goals & perceptions of others (vocal. = no!)
Intention movements - function/meaning inherent if und. goals
Attention getters - function/meaning inherent if und. displays (+percept)
But not co-operative comm. b/c no skills & motivations of shared intentionality
Gestures one-way (not imitated), not collab. (no reqs. for clarification)
Helpful partner leads apes to indiv. imperatives, but not co-op. comm.
Some References
Call, J. & Tomasello, M. (1994). The production and comprehension of referential pointing by orangutans. Journal of Comparative Psychology, 108, 307-317
Call, J. & Tomasello, M. (Eds). (in press). The gestural communication of apes and monkeys. Erlbaum.
Call, J. & Tomasello, M. (1996). The effect of humans on the cognitive development of apes. In A. Russon, K.A. Bard, S.T. Parker (Eds.), Reaching into Thought: The Minds of the Great Apes. Cambridge U Press.
Hare, B., Call, J., & Tomasello, M. (in press). Chimpanzees deceive a human by hiding. Cognition
Hare, B. & Tomasello, M. (2004). Chimpanzees are more skillful in competitive than in cooperative cognitive tasks. Animal Behaviour, 68, 571-81
Hare, B., Brown, M., Williamson, C., & Tomasello, M. (2002). The domestication of social cognition in dogs. Science, 298, 1634-36.
Hermann, E. & Tomasello, M. (in press). Apes' and children's understanding of cooperative and competitive motives in a communicative situation. Developmental Science.
Liebal, K. , Pika, S. & Tomasello, M. (2006). Gestural communication in orangutans. Gesture, 6, 1 - 38.
Liebal, K., Call, J., & Tomasello, M. (2004). The use of gesture sequences by chimpanzees. American Journal of Primatology, 64, 377-396.
Liebal, K., Pika, S., Call, J., & Tomasello, M. (2004). To move or not to move: How apes adjust to the attentional state of others. Interaction Studies, 5, 199-219
Pika, S. , Liebal, K., & Tomasello, M. (2003). Gestural communication in gorillas. American Journal of Primatology, 60, 95-111.
Pika, S. , Liebal, K., & Tomasello, M. (2005). Gestural communication in bonobos. American Journal of Primatology, 65, 39-61.
Pika, S. , Liebal, K., Call, J., & Tomasello, M. (2005). Gestural communication of apes. Gesture, 5, 41 - 56.
Tomasello, M. (1996). Do apes ape? In J. Galef & C. Heyes (Eds.), Social Learning in Animals: The Roots of Culture. Academic Press
Tomasello, M. & Call, J. (1997). Primate Cognition. Oxford University Press.
Tomasello, M. & Camaioni, L. (1997). A comparison of the gestural communication of apes and human infants. Human Development, 40, 7-24.
Tomasello, M. (in press). Why don't apes point? N. Enfield & S. Levinson (Eds.), Roots of Human Sociality. Wenner-Grenn.
Tomasello, M., Call, J., & Gluckman, A. (1997). The comprehension of novel communicative signs by apes and human children. Child Development, 68, 1067-1081.
Tomasello, M., Call, J., Nagell, K., Olguin, R., & Carpenter, M. (1994). The learning and use of gestural signals by young chimpanzees: A trans-generational study. Primates, 37, 137-154.
Tomasello, M., Call, J., Warren, J., Frost, T., Carpenter, M., & Nagell, K. (1997). The ontogeny of chimpanzee gestural signals: A comparison across groups and generations. Evolution of Communication. 1, 223-253.
Tomasello, M., Call, J., & Hare, B. (2003). Chimpanzees understand psychological states: The question is which ones and to what extent. Trends in Cognitive Science, 7, 153-156
Tomasello, M & Zuberbüler, K. (2002). Primate vocal and gestural communication. In M. Bekoff, C. Allen, & G. Burghardt (Eds), The Cognitive Animal: Empirical and Theoretical Perspecitives on Animal Cognition. MIT Press.