Slide 1: Peter Gärdenfors The role of cooperation in the evolution
of human communication SEDSU project : SEDSU project Stages in the Evolution and Development of Sign Use Work done in collaboration with
Ingar Brinck and Mathias Osvath
at Lund University Hominin ancestors : Hominin ancestors What makes human thinking so unique? : What makes human thinking so unique? Slide 5: Levels of Levels of cognition cooperation Levels of
communication Prospective cognition : Prospective cognition ”Mental time travel” representing future needs and events
Involving ”detached” representations, suppressing current sensations
Unique in humans? (the Bischof-Köhler hypothesis)
Long ranging life style of hominins promoted prospective cognition Oldowan tools ˜ 2.5 Mya : Oldowan tools ˜ 2.5 Mya Main components of the Oldowan culture : Main components of the Oldowan culture Manufacturing and use of stone tools
Transport of artefacts (at least the stone tools)
Transport of pieces of carcasses
Use of accumulation spots
Division of labor (?) Plummer (2004): ”Flaked stones and old bones”, Yearbook of Physical Anthropology Homo transportens : Homo transportens Intersubjectivity: Components of a ”theory of mind” : Intersubjectivity: Components of a ”theory of mind” Understanding the emotions of others
Understanding the desires of others
Understanding the attention of others
Understanding the intentions of others
Understanding the beliefs of others Representing the beliefs of others: False belief tasks : Representing the beliefs of others: False belief tasks 0. Subjects are three- to five-year-old children.
1. The children are first shown a Smarties tube and then asked what they think is in it. All the children reply “Smarties” (or “sweets”).
2. When the tube is opened it is found to contain pencils.
3. Then the tube is closed.
4. The children are now asked what a friend, who has not yet seen what is in the tube, will say that it contains.
5. The three-year-olds generally answer “pencils” whereas most of the older children say “Smarties.” Slide 12: Levels of Levels of cognition cooperation Levels of
communication Levels of cooperation : Levels of cooperation Ingroup vs. outgroup behaviour
Reciprocal altruism Reciprocalaltruism : Reciprocalaltruism I scratch your back
- you scratch mine Modeled by iterated prisoners’ dilemmas
Building up trust between two individuals Levels of cooperation : Levels of cooperation Ingroup vs. outgroup behaviour
Cooperation about future goals
Indirect reciprocity (the good Samaritan) Building a reputation : Building a reputation Nowak & Sigmund, 2005 Slide 17: Connections between cooperation, cognition and communication Slide 18: Levels of Levels of cognition cooperation Levels of
communication Basic levels of communication : Basic levels of communication Type of sign (Peirce)
• Signal (index)
• Symbol Type of communication
Most animal communication
Language with syntax Communicating about our inner worlds : Communicating about our inner worlds Why humans evolved symbolic communication : Why humans evolved symbolic communication The Oldowan culture constituted an ecological niche containing evolutionary forces that fostered prospective cognition.
Prospective cognition made cooperation about future goals beneficial for the hominins.
Protolanguage is an efficient way of solving problems concerning cooperation about future non-existent goals. Symbols are required for communication about future goals : Symbols are required for communication about future goals If the goal is present, then signaling is sufficient. Joint attention to a referent : Joint attention to a referent Joint attention to a referent : Joint attention to a referent Future goal Symbols are required for communication about future goals : If the goal is present, then signaling is sufficient.
If the communicated goal is not present, detached representations are required. Iconic miming may work, but only if the signaler and receiver have sufficient common knowledge about the goal.
If the communicated goal is a novel entity that does not yet exist, combinatorial symbols (protolanguage) are required.
Dessalles: Protolanguage can describe scenes.
Explains why no other species uses symbols. Symbols are required for communication about future goals Building a reputation : Building a reputation Nowak & Sigmund, 2005 Indirect reciprocity requires language with (minimal) syntax : Indirect reciprocity requires language with (minimal) syntax Communication concerning reputation requires:
Reference to individuals in their absence
Express that “x was good to y” and “y was bad to x”
Express that “y has bad reputation”
Involves marking roles, which is done by syntax Two hypotheses concerning the evolution of language : Two hypotheses concerning the evolution of language Protolanguage is an efficient system for cooperation about future goals
Language with syntax is an efficient system for maintaining indirect reciprocity Possible archaeological evidence : Possible archaeological evidence For prospective cooperation:
Division of labor
Big game hunting
For indirect reciprocity:
Indications that reputation has social impact Slide 30: Peter Gärdenfors The role of cooperation in the evolution
of human communication Representing the emotions of others: Empathy : Representing the emotions of others: Empathy Empathy: perception of emotion in another activates the same emotion in the receiver
Evidence for empathy in mammals
Speculation: depends on mirror neurons
Chimpanzees exhibit consolation behaviour
Cognitive empathy: subjects understand the emotions of others without having the emotion themselves Representing the attention of others : Representing the attention of others Children at 6 months can follow the gaze of their mother if she turns her head
At 12 months they can follow the gaze of their mother if she just moves her eyes
At 18 months they can follow the gaze of their mother if she looks outside their field of vision (requires allocentric representation of space)
Chimps can also follow gazes in an allocentric way Representing the intention of others : Representing the intention of others Understanding the pursuit of goals:
Experiments where an adult (1) deliberately avoids handing over or (2) fails to hand over a reward (a toy or food)
Children from 9 months and chimps react differently to (1) and (2), i.e. to whether the failure was deliberate or not
Is this sufficient to claim that chimps represent the intentions of others? How to avoid prisoners’ dilemmas : How to avoid prisoners’ dilemmas Iterated games (trust can be built up)
”Guilt aversion” (Charness and Dufvenberg 2006) changes outcomes of a prisoners’ dilemma - increases cooperation
Presumes understanding desires
May explain egalitarianism in human (hominin) societies