Seminar � social cognition in chimpanzees and dolphins

Greg Detre

Monday, 27 November, 2000

Zoology, Lecture theatre B

Josep Call, Institute for Evolutionary Anthropology, Leipzig

call@eva.mpg.de

 

Apes

social interaction is more than just responding to social cues

chimps (+ other animals?) develop behavioural rules � this is more than just social S-R, and allows flexible + appropriate behaviour in novel situations = social cognition

 

penis-offer and poke-at videos

Tomasello et al 1994, 1997 � visual gestures done mostly when others are looking, less so for auditory, and tactile gestures are done as often as not when others are looking

gaze-following

into distant space

around barriers

cues or rules?

prevent behavioural cues

prevent contextual cues

novel situtations and na� individuals

Occluder test (Hare et al., 2000)

2 chimps, both behind doors. when the doors are partially open, they can see into the room. there is a barrier occluding the dominant chimp�s view of the banana piece, but he can see the 2nd piece on the other side of the room, while the subordinate chimp can see both.

in hidden-visible condition, the subordinant with privileged knowledge of the situation goes for the hidden one more often

the dominant may be hinting where it is going by where it is looking � NO

the subordinate may be readin where the dominant is going � NO

the subordinate prefers rewards in front of the barrier � NO

Informed/uninformed/misinformed test

move the food to behind a barrier after being placed behind a first barrier

dominant sees food placement baiting sometimes, at choice: barrier vs barrier

subordinate sees food placement baiting, at choice � food vs empty

What the studies show

Behavioural abstraction � cues and learning alone are not enough, need a notion of seeing

Analogous to physical cognition � oddity + analogical reasoning

Intervening Variable (Whiten, 1996)

What the studies do not show

do they have subjective experiences?

do they have access to the rules, whether they understand the rules that govern their behaviour or not?

understanding of mental states? knowledge/ignorance, false belief?

Parallels with children?

rabbit hides carrot under red bucket, rabbit goes away, hedgehog moves the carrot to the blue box, when the rabbit comes back, where will it look for the carrot? children >4 correctly say that the rabbit will look under the red bucket (Baron-Cohen, 1985)

Dolphins

Tschudin et al. in prep, Dunbar in prep.

baiter hides the fish with the dolphin watches

the communicator leaves, and the baiter switches

the communicator returns, and points (wrongly)

the dolphin decides which box it wants (i.e. which direction its orientated towards)

������ false belief � dolphins did well

cue control � not well at all

 

Q&A

you used female chimps in the occluder tests � what if you used males?

males + females together, the males would ignore the banana

the experiment might work if you used 2 males and a female as bait

 

 

My questions

have you swapped the subordinate-dominant chimps?

what about using the dolphins to communicate