Do Apes have a TOM Flashcards
Evidence relating to apes’ ability to understand the mental states of others wrt:
–Goals & intentions
–Perception & knowledge
–False belief
So, do chimps have a theory of mind?
Povinelli- behavioural rules
Tomasello- theory of mind in some sense
•reports of ‘mentalising’ in the wild (anecdotes)
•Evidence that they understand: goals/intentions and seeing=knowing
•BUT: failure to solve FB tasks in lab (until 2016!)
•Mixed evidence
•Difference for
–Competition vs cooperation ???
•Different ways to interpret the results
Authors claim
Great apes anticipate that other individuals will act according to false beliefs
Competing explanation:
apes used knowledge of abstract rules — specifically, that people tend to look for objects in the place they last saw them
Unique to humans?
possibility:
-chimpanzee’s mind seems similar to ours precisely because it is similar
2nd possibility:
- We cannot help distorting the chimpanzee’s mind, recreating it in our own image
Premack and Woodruff (1978): Does the chimpanzee have a theory of mind?
- Chimp offered correct solutions to an actor’s problems
* Suggesting she could infer the actor’s intentions
Woodruff & Premack (1979)
When human cooperated with chimpanzee in finding a goal (hidden incentive):
•chimpanzees able to produce and comprehend behavioural cues which conveyed accurate locational information
When human and chimpanzee competed for the goal:
•chimpanzees learned to withhold information or mislead the recipient
•and to discount or go against the sender’s own misleading cues
But only after A LOT of training!
Provides evidence of a capacity for intentional communication / deception
Do chimps have a theory of mind
The debate
Povinelli camp
•Chimps do not reason about others’ beliefs, or any other mental states
•same behaviours, but not same underlying psychological mechanisms
Tomasello camp
•Chimps have ToM in some respects, but not in others
•No evidence whether they understand false beliefs
•BUT: chimps understand:
–goals and intentions, and
–perception and knowledge
of others
Povinelli camp
- Chimps do not reason about others’ beliefs, or any other mental states
- same behaviours, but not same underlying psychological mechanisms
Tomasello camp
Chimps have ToM in some respects, but not in others
•No evidence whether they understand false beliefs
•BUT: chimps understand:
–goals and intentions, and
–perception and knowledge
of others
Do chimps have a theory of mind
Behavioural abstraction Hypothesis
•Understand only surface-level of behaviour and form behavioural rules
•‘BAH’ posits that chimpanzees:
–make predictions about future behaviours that follow from past behaviours, and
–adjust their own behaviour accordingly.
Behavioural Abstraction Hypothesis
•Understand only surface-level of behaviour and form behavioural rules
•‘BAH’ posits that chimpanzees:
–make predictions about future behaviours that follow from past behaviours, and
–adjust their own behaviour accordingly.
Beyond behavioural rules
•Chimps highly social animals – need to anticipate what others do
•Observing previous behaviour and deriving set of behavioural rules enables behavioural prediction
•BUT: Inferring states not only in previously observed situations,
but also in novel situations
•Need to anticipate actions based on goals and intentions
Call and Tomasello 2008
Understanding goals and intentions
➢ Chimps show understanding of goals or intentions
➢ Imitation studies contradict Povinelli’s behavioural abstraction hyp
Buttelman et al 2007
Understanding goals and intentions
- chimps imitate rationally
- Imitated E’s novel action when he seemed to do it intentionally but NOT when this was due to a physical constraint
- chimps understand other’s goals and intentions
Altruistic helping requires
- Cognition = understanding of another’s goals
* altruistic motivation = no benefit/costly
Altruistic helping
Warneken and Tomasello 2006
•Study 1: 18mos infants (N=24) Study 2: 36-54mos chimps (N=3) •Procedure: 10 situations, 4 categories 1.Out-of-reach 2.Access thwarted by physical object 3.Achieving wrong result 4.Using wrong means 3 request phases (10s focus only, 10s alternate gaze, 10s verbalise)
Altruistic helping
Warneken and Tomasello 2006
Infant data
- children and chimps both willing to help without reward or praise
- Chimps helped more in reaching tasks than other tasks (salient cue?)
- differ in ability to interpret others’ need for help?
- Methodological note: cooperation vs competition
Understanding others’ perception and knowledge
Important to know not only the goals of another but also:
•What s/he can see
•What s/he knows
will help determine what s/he does.
Povinelli and Eddy 1996
Can chimps follow gaze
•chimp looks to spot behind her
•chimp tries to look behind screen
–target cannot be what I cannot see
Understanding perception
Negative evidence
Povinelli and Preuss 1995
Povinelli and Eddy 1996
Chimps beg for food from blindfolded human
Begging is indiscriminate
can chimps appreciate what others ‘see’?
•Chimps experts at noticing finest subtleties of eye movements and gaze directions
•possess and learn rules about visual perception
•BUT:
these rules do not necessarily incorporate the notion that seeing is “about” something
–oblivious to psychological distinction between begging from blindfolded carer vs non-blindfolded
•Chimps cannot reason about seeing?
Pavinelli and Eddy 3 explanations
- general delay in psychological development in chimpanzees
- chimpanzees may possess a different (but nonetheless mentalistic) theory of attention
- subjective understanding of visual perception may be unique to humans
Kaminski et al 2004
Understanding perception
Positive evidence
- Chimps begged more when they were being watched
* Sensitive to both body and face orientation but not eyes
Co-operation vs competition
- Negative results in the lab required co-operative communication with humans
- Cf. informal observations of ‘mentalising’ in the wild involved competition with conspecifics
Understanding knowledge and perception
Positive evidence
Hare, Call & Tomasello 2001
Competitive paradigm
chimpanzees can reason about others’ knowledge on the basis of what others have / have not seen
Two interpretations
Behavioral Abstraction
Mental-state attribution
•“He was present and facing the food when it was placed where it is now therefore he is likely to go after it”
•“He was not present when the food was placed where it is now therefore he is less likely to go after it”
Mental-state attribution
•“He was present and facing the food when it was placed where it is now so he saw the food placed and currently knows where it is therefore he is likely to go after it”
•“He was not present when the food was placed where it is now so he didn’t see it, therefore he doesn’t know.. therefore he is less likely to go after it”
Hare et al 2006
Understanding perception and knowledge
Positive evidence
•Perceptions differ:
–need to distinguish between own and other’s vision
(seeing = knowing)
•chimps show visual and auditory perspective taking
Hare et al 2006
Visual perspective taking
Melis, Call & Tomasello (2006)
Auditory perspective taking
- In the presence of a human competitor, chimps preferred to reach through a silent rather than noisy tunnel
- Suggests they are sensitive to what others can hear
- Are able to manipulate the auditory perception of a competitor
Call and Tomasello 2008
Studies on chimps and human infants knowledge of perception and knowledge
➢Do this without past experience of these situations (so no rule learned)
➢contradict Povinelli’s behavioural abstraction hyp
Call and Tomasello, 1999
A test for FB understanding no.1
1.man watches as treat hidden under one of two cups; chimp can’t see 2.man leaves 3.cups are swapped 4.man returns and points to one cup 5.chimp single chance to retrieve -> chimp scores if looks under cup man didn’t point to
Test for FB understanding number 2
- Testing monkeys in the wild
* Participants opportunistically sampled by searching the island
Monkeys represent others knowledge but not Their beliefs
Marticorena et al 2011
Experiment 1
Used a Violation of Expectancy method similar to Onishi & Baillargeon (2005) with rhesus monkeys
Looked for longer when actor fails to look for object in correct location when she is informed
Experiment 2
False belief continued
No difference in looking time
Results
Marticorena et al 2011
Monkeys represent others knowledge but not their beliefs
•Findings suggest they can represent whether the actor is knowledgeable or ignorant
•However, they did not expect the actor to search in the wrong location in line with their (false) belief
Monkeys can represent the knowledge and ignorance of others but not their beliefs – in contrast to 15mo infants!
Test for FB understanding number 3
Krupenye et al 2016
Latest evidence using eye-tracking.
Used anticipatory gaze paradigm based on Southgate et al. (2007)
•Authors’ claim: Great apes anticipate that other individuals will act according to false beliefs
•Competing explanation: apes used knowledge of abstract rules — specifically, that people tend to look for objects in the place they last saw them
