Theory of mind in apes Flashcards
Premack and Woodruff (1978) - does the chimpanzee have a theory of mind?
- chimp offered correct solutions to an actor’s problems
- suggests she could infer the actor’s intentions
- problems such as trying to get into a locked cabinet, broken boiler
Povinelli’s view on chimp ToM
- chimps do not reason about other’s beliefs, or any other mental states
- same behaviours, but not the same underlying psychological mechanisms
Tomasello’s view on chimp ToM
- chimps have ToM in some respects but not in others
- no evidence whether they understand false beleifs
BUT - chimps understand goals, intentions, perception and knowledge of others
What is the behavioural abstraction hypothesis?
- understand only surface-level of behaviour and form behavioural rules
- chimps make predictions about future behaviours that follow from past behaviours and adjust their own behaviour accordingly
Understanding goals and intentions - Buttelmann et al., 2007
Goal = what person is trying to do or achieve
Intention = the action plan chosen for pursuing this goal
- 6 chimps 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.
- Press the panel – made a noise or there was a flash – appealing to touch
- Hands were busy holding something – taping panel with foot makes sense
- Hands were free – taping panel with foot doesn’t make sense
- When the chimps given task would they imitate action when hands are free even though it doesn’t make sense
Altruistic helping - Warneken & Tomasello (2006)
Altruistic Helping requires:
Cognition = understanding of another’s goals
altruistic motivation = no benefit/costly
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 findings
- 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
- Every child helped in initial 10s phase
- Chimpanzees took a bit longer for a response
- Not representative of chimps in the wild – in wild much more interested in competition
What is the mentalistic significance of eye gaze?
The eyes communicate vital information about an individual’s mental states e.g.:-
focus of attention
object of reference, desire or aversion
intent to act
feelings, mental activities
Eyes – window to the soul
early foundation of eye gazing in humans
Early sensitivity to gaze in infancy is well-documented (Butterworth & Jarrett, 1991; Maurer & Salapatek, 1976).
Infants prefer:
Open rather than closed eyes (Batki et al., 2000).
Direct rather than averted gaze (Farroni et al., 2002).
Begin gaze following at 6months (D’Entremont et al.,1997).
- as early as 2 months old – infants look at eyes
- 6 months – babies track where someone is looking/moving to
- Establishing what someone is attending to – can start to understand about their mental state
- Precursors
Can apes follow gaze? Povinelli & Eddy (1996); Tomasello et al., (2007)
Ape looks to spot behind her.
Ape tries to look behind screen.
Apes rely more on head direction than eye direction (c.f infants).
But what can we conclude from these findings?
- eyes are more important for infants than apes
Understanding perception, negative evidence (eye gazing) - Povinelli & Preuss, 1995 and Povinelli & Eddy, 1996
Will chimps beg for food discriminately from different carers
One carer cannot see the chimp, blindfold over eyes, other carers mouth was covered so they couldn’t speak
Same objects and stimuli used for each carer
Chimp showed indiscriminate begging
Chimps didn’t understand what ‘seeing’ means
More cognitive demands – had to focus on more than one carer
Can chimps appreciate what others ‘see’?
- Chimps experts at noticing eye movements and gaze directions
- 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?
Understanding perception, positive evidence (eye gazing) - Kaminski et al., 2004
- Chimps begged more when they were being watched.
- Sensitive to both body and face orientation but not eyes.
- Positive evidence chimps can reason about what others see
- Vary orientation of where someone sat
- Eyes open/closed – chimps didn’t know the difference, no point begging for food
- Eyes open/back turned – focused on person with eyes open more than person facing backwards
- Pay attention to head orientation of the person
- No diff between facing backwards and head being turned
- Sensitive to body and face orientation but not eyes
Eyes – spotlight of attention
Face/body – floodlight to attention
Understanding knowledge & perception: Positive evidence (competitive paradigm) - Hare, Call & Tomasello, 2001
- Findings suggest chimpanzees can reason about others’ knowledge on the basis of what others have / have not seen
- Subordinate Chimp only retrieve food if dominant chimp hadn’t seen where the food was hidden
Didn’t retrieve food if dominant chimp had seen where the food was hidden
Understanding perception and knowledge, Positive evidence (seeing = knowing) - Hare et al, 2006
- Human sat in sealed box with food on either side
- Chimp could approach food from either side
- Chimps approach from the back – side where they weren’t looking/oriented
- Reasoned based on face orientation
- No person competing – went to left side more often but not a significant difference/didn’t have a preference for the left
