Social cognition in young children and chimpanzees

1
Social cognition in young children and chimpanzees

• Malinda Carpenter
• Max Planck Institute for Evolutionary
  Anthropology, Leipzig, Germany
• carpenter_at_eva.mpg.de

2
Introduction to this course

• Many differences between apes and humans
• culture
• artifacts
• beliefs, customs, rituals
• language
• collaborative activities
• institutions (collective beliefs, e.g., money,
  marriage, government)
• skyscrapers
• symphony orchestras
• summer schools
• everyday life
• showing your vacation photos
• holding a door open for someone
• taking a walk together

3

• Where do these differences come from?
• language
• theory of mind ( ? )
• shared intentionality ?
• We propose that all these abilities involve
  sharing and collaboration. The crucial
  difference between human cognition and that of
  other species is the ability to participate with
  others in collaborative activities with shared
  goals and intentions shared intentionality
  (Tomasello, Carpenter, Call, Behne, Moll,
  2005).
• Two components
• understanding of others psychological states
• motivation to share psychological states with
  others

X
4

• Outline
• theory of mind (understanding of others mental
  states)
• beliefs, knowledge, desires
• intentions, attention
• shared intentionality
• some types of social learning
• some types of communication
• motivation to share psychological states with
  others
• collaboration
• comparisons
• infants and apes collaborative vs. individual
  versions of each
• children with autism
• discussion, evolutionary story
• questions, discussion welcome!

5
Theory of mind Childrens and chimpanzees
understanding of others mental states

• Part 1 False beliefs, knowledge, and desires

6
Theory of mind

• Your roommate goes to her dresser, pulls on the
  handles of a drawer several times, harder and
  harder, hits the sides of the dresser, pulls
  again, and then walks away.
• random pulling/hitting behavior?
• or
• She thought something she wanted was in there
  and she was trying to open the drawer to get it
  out.
• We make sense of others behavior by figuring
  out why theyre behaving the way they are by
  figuring out what theyre thinking, what they
  want, what they are intending.

7
Theory of mind

• Your roommate goes to her dresser, pulls on the
  handles of a drawer several times, harder and
  harder, hits the sides of the dresser, pulls
  again, and then walks away.
• random pulling/hitting behavior?
• or
• She thought something she wanted was in there
  and she was trying to open the drawer to get it
  out.
• We make sense of others behavior by figuring
  out why theyre behaving the way they are by
  figuring out what theyre thinking, what they
  want, what they are intending.

8

• Theory of mind the attribution of mental
  states (e.g., thoughts, beliefs, desires,
  intentions) to others (and self) (Premack
  Woodruff, 1978).
• Understanding of mental states (mindreading)
  allows us to explain observable events (actions)
  by inferring unobservable entities (beliefs,
  desires, etc.).
• Also involves understanding that others mental
  states may differ from ones own, and may differ
  from reality (e.g., false belief, unfulfilled
  attempt).
• We use it everyday make sense of others
  behavior, deception, prediction, etc.

9

• Debate over whether really a theory, and how
  children do this (acquire rules and principles
  vs. use own imagination to simulate others
  mind).
• Original definition included all mental states,
  but most tests are of beliefs, especially false
  beliefs.
• one reason beliefs are often less directly
  observable in behavior, can be more detached from
  reality
• great interest in this search ? 729 papers on
  false belief
• Generally accepted criterion for crediting
  someone with a theory of mind is an understanding
  of others false beliefs
• important that the others belief does not match
  reality, so cannot answer based on own
  belief/knowledge if ask about others true
  beliefs, children could respond correctly even if
  didnt know anything about others minds, by
  answering according to what they know

10

• Understanding of others beliefs
• Beliefs
• Children begin to explain others behavior in
  terms of their beliefs around age 3 years. For
  example
• Sam wants to find his puppy. The puppy might
  be hiding in the garage or under the porch. But
  Sam thinks the puppy is under the porch. Where
  will Sam look for the puppy in the garage or
  under the porch? (Wellman Bartsch, 1988)
• Three-year-olds pass this test. But 3-year-olds
  do badly on tests of false beliefs.

11

• False Beliefs
• standard tests
• Sally-Anne or Maxi test (change of location)
  Baron-Cohen, Leslie, Frith (1985) Wimmer
  Perner (1983)
• Smarties test (deceptive box) Perner, Leekam,
  Wimmer (1987)

12

• False Beliefs
• Sally-Anne (Maxi) test
• (Baron-Cohen, Leslie, Frith, 1985 Wimmer
  Perner, 1983)
• control questions
• Where is the marble really?
• Where did Sally put the marble at the beginning
  of the story?
• 3-year-olds say box, where it is (fail)
  4-year-olds say basket

from Frith (1989)
13

• False Beliefs
• Smarties test
• (Perner, Leekam, Wimmer, 1987)
• tests self and other self other answers
  related (Gopnik Astington, 1988)
• control questions
• Is that whats really in here?
• What is really in here?
• again, 3-year-olds fail (say pencil)
  4-year-old pass (say Smarties)

?
?
from Frith (1989)
14

• Development of understanding of false beliefs
• Meta-analysis on over 100 studies using the
  standard, verbal tests (Wellman, Cross, Watson,
  2001)
• younger than 3½ years below chance (choose
  incorrect)
• 3½-4 years at chance
• older than 4 years above chance (choose
  correct)
• Implicit tests
• Clements Perner (1994) standard Sally-Anne
  scenario, but measured to which location children
  looked in anticipation of the protagonists
  return. Evidence of implicit understanding at
  age 211.
• Onishi Baillargeon (2005) 15-month-olds
  looked longer at displays in which an actors
  search for a toy was inconsistent with her belief
  about the toys location.

15
Onishi Baillargeon (2005)
Infants watch as actor takes object, plays, puts
in green box. Pause, curtain Actor reaches
into green box as if to take object. Pause,
curtain Belief induction trial e.g., False
Belief (unseen switch) infant but not actor
sees object move from green to yellow box. Test
trial e.g., actor reaches into yellow box.
Pause until trial ends
16

• Other belief induction trials
• True belief (seen switch) actor watches as
  object moves from green to yellow.
• True belief (no switch) actor watches as yellow
  box moves but object does not come out of green
  box
• False belief (one seen, then one unseen switch)
  actor watches as object moves from green to
  yellow, then does not watch as object moves back
  to green.
• Test trial for half the infants actor reached
  to yellow and for half reached to green box.
• Results
• In each of the four conditions, infants looked
  longer during the test when the actor reached to
  the location that was inconsistent with where she
  thought the object was (where she correctly or
  falsely believed - ? it to be).
• False belief understanding in 15-month-olds??

17

• Given these findings, why do 3-year-olds fail the
  standard tests?
• Zaitchik (1990) compared out-of-date beliefs to
  out-of-date photographs (same structure,
  cognitive demands)
• 3-year-olds fail this too
• executive function problems? (difficulty
  inhibiting the perceptually salient response?
  not a problem in tasks using looking measures)

from Happé (1994)
18

• Factors influencing childrens performance
• Executive function
• performance on false belief tasks is related to
  performance on executive function tasks (e.g.,
  inhibition, working memory)
• in versions with no pull of the real (the
  object is no longer in the container), many
  3-year-olds pass (Carpenter, Call, Tomasello,
  2002 Gergely colleagues eating the Smarties
  task).
• Language
• question asked (where will she look first?
  helps a little)
• but verbal and nonverbal tests yield similar
  results
• correlations between false belief understanding
  and language skills (especially the types of
  constructions that include mental state terms I
  know that x She thinks x)
• deaf children of nonsigning parents show delays
  in false belief understanding
• Family
• children with older (but not younger) siblings do
  better (Perner, Ruffman, Leekam, 1994).
• children whose mothers generally talk more about
  mental states do better (Dunn et al., 1991).

19
(No Transcript)
20

• Understanding of others knowledge
• e.g., Povinelli deBlois (1992) guesser vs.
  knower
• 3- and 4-year-olds
• the hider E hid a surprise in one of two cups
  while the leaver E was out of the room.
• When the leaver E returned, both Es pointed to
  a cup (hider to correct and leaver to incorrect).
• 4-year-olds chose the correct cup 3-year-olds
  did not.

21
ONeill (1996)

• 2-year-olds
• Children watched as a toy was hidden in one of
  two out-of-reach containers.
• Sometimes their parent witnessed the hiding too
  sometimes not.
• Childrens requests were more informative when
  parents were ignorant than knowledgable (more
  gestures, identifying verbalizations).

• But if the parents eyes are covered at an
  irrelevant point in the hiding process (before
  but not during the hiding), young 2-year-olds
  treat the parent as ignorant (Dunham, Dunham,
  OKeefe, 2000).

22
Tomasello Haberl (2003)

• 12- and 18-month-olds
• E and the child play with two toys successively.
  While E2 and the child play with a third toy,
• E is out of the room (experimental condition)
• E stands near the door and watches (control
  condition).
• E returns and shows excitement toward the group
  of three toys.
• E tells the child Give it to me.

23

• In the experimental condition, children of both
  ages chose the new object significantly more
  often than would be expected by chance.
• 12- and 18-month-olds can identify which of
  several objects is new to another person based on
  her past visual experience (knowledge by
  acquaintance).

24
(No Transcript)
25

• Understanding of others desires
• Repacholi Gopnik (1997)
• 14- and 18-month-olds
• E presents two bowls of food one of crackers
  (appealing food), one of broccoli (unappealing
  food).
• Child tastes each food and tells E which he
  prefers.
• Then E tastes each food and produces either a
  happy emotional expression (Mmm!) or a
  disgusted expression (Eww!), depending on the
  experimental condition.
• E holds her hand out in between the two bowls and
  asks the child Can you give me some? (without
  looking at or indicating either bowl).
• 18-month-olds gave the food E was happy about,
  even if it was not the one they themselves
  preferred. 14-month-olds gave the food they
  preferred.

26
Summary It depends on the measure

• False belief
• verbal tests 4 years
• less verbal, but still action measure tests 3
  years
• implicit, looking measure tests 15 months
• Knowledge/ignorance
• guesser vs. knower 4 years
• tailor communication 2 years
• knowledge by acquaintance 12 months
• Desire
• 18 months

27

• Apes
• False beliefs
• few nonverbal tests (mostly Call Tomasello et
  al.)
• only one study showing evidence consistent with
  false belief understanding (Call, Hare,
  Tomasello) but other explanations are possible
• Knowledge/ignorance
• guesser vs. knower (Povinelli)
• what have seen in past (Call, Hare, Tomasello)
• informing (Call Tomasello, Gomez, Whiten)

28

• Apes
• Desires
• Buttelmann, Call, Tomasello (in preparation)
  Ape knows that E hid two pieces of (good) food.
  Ape sees E react happily to one container and
  with disgust to the other, then sees E eating.
  Ape is allowed to choose a container. Apes
  choose the container E reacted to with disgust,
  assuming that he ate the food he reacted to
  happily. ? Apes know something about the
  relation between desire (emotion?) and action.

29

• Children with autism
• False beliefs
• many studies, consistent results children with
  autism have difficulty with false belief tests
• why?
• some evidence of difficulty with executive
  function, but not so clear-cut
• in addition, they pass the out-of-date photo
  test, which has the same executive function
  demands (Leslie Thaiss, 1992).
• also not because trouble with representations in
  general (they pass the out-of-date photo test
  Leslie Thaiss, 1992)
• seems to be trouble with mental representations
  specifically but not all mental states

30

• Children with autism
• Knowledge/ignorance
• understanding knowledge easier than false belief
• e.g., Leslie Frith (1988) E2 watched as E1
  hid a counter in one hiding place. E2 left. E1
  hid another counter in another hiding place.
  Child asked where will E2 look for a counter
  when she comes back? Few passed (23-44) but
  more children passed this than false belief.
• Desires
• Baron-Cohen (1991) children with autism
  understand the relation between desire and
  emotion
• If Jane wanted x and was given x she would be
  happy if she wanted x and was given y she would
  be sad

31

• Summary
• Apes, children with autism have trouble
  understanding false beliefs
• also deaf children raised by nonsigning parents
• Three-year-old and younger children have trouble
  understanding false beliefs too (depending on the
  study), but probably for different reasons.
• apes, children with autism no understanding of
  complex mental states
• younger children task demands (?)
• Seminar Well discuss the different false
  belief tests, trying to figure out whether they
  really measure false belief understanding
  (alternative explanations, methodological issues,
  other problems). Well also discuss ways to test
  understanding of (unobservable) mental states
  nonverbally (in the meantime, please try to think
  of some!).
• (plus any other questions you have)

32
(No Transcript)
33
Seminar

• questions?
• discussion of false belief tests
• do they really test understanding of false
  belief?
• might not need false belief understanding to
  pass instead learned rules of thumb, e.g.,
  people usually look for things in the last place
  they saw them
• Lohmann, Carpenter, Call, Tomasello (2005)
  update by telling
• (Moll, Carpenter, Tomasello sound)
• standard tests have other demands besides false
  belief understanding verbal, executive function
  demands
• other problem with standard tests tests dont
  always correlate
• what does Onishi Baillargeon show?
• how to design nonverbal theory of mind tests?
• control condition true belief (chance issue)
• measures?