Course P1.1 – General Foundations
Biological Bases of Cognition (Cognition in
Chimpanzees)
Dr Stephen Walker
December 16th 2004
Cognitive processes in animals, especially primates.
Whereas ethologists and behaviourists used to
explain animal behaviour in terms of reflexes, it
is common now to talk of animal cognition.
 The great apes are more closely related to the
human species than other animals, and might thus
be expected to have more human-like cognition.
But hard evidence for this is weak, and some
authors reject this idea (Macphail, 1987; Heyes,
1998).
Primate Cognitive Superiority?
• An extreme case of this notion was the
expectation that, with sufficient training, infant
apes would develop linguistic competence. (E.g.
Gardener and Gardener, 1969).
• There is now a wide consensus that what
chimpanzees achieve, even after years of
training, merely emphasizes the importance of
inherited human specialized capacities.
Human-like capacities other than
language
• Piagetian tests suggest that ape infants go
through similar stages to human infants at
least during the sensori-motor period (1st
year).
• Imitation and social learning may be primate
characteristics.
• Tool using occurs in some populations
• Memory for recent events in primates may
be very extensive (Menzel, 1973).
Mental attribution and “Theory of Mind”
• Self-recognition in mirrors seems to only occur in
apes.
• It is suggested that this indicates a broader capacity
for introspection and for attributing mental states to
other individuals (Gallup et al, 1995; Boysen and
Himes, 1999; Call, 2001; Tomasello, 2000).
• Povinelli (1993) reviews this suggestion, but others
such as Heyes (1998) and Povinelli et al. (2000) are
sceptical even about self-recognition.
Jolly (1972) cover
2nd Edition is Jolly (1985)
Taxonomy of Primates (an Order of
Mammals: p.5 of handout
There are two sub-orders of the order Primates. One sub-order
includes humans, apes and monkeys, and the other is for
Prosimians, and includes the lemurs of Madagascar, lorises (e.g.
bushbabies) and tarsiers.
PROSIMII (The older of the two suborders of Primates)
Prosimians: = the lemurs of Madagascar, lorises (e.g.
bushbabies) and tarsiers.
Anthropoidia
ANTHROPOIDEA (A suborder of Primates)
This includes 3 superfamilies, the superfamily of humans and apes
and two superfamilies of monkeys:
Humans and Apes (Hominoidea). Includes extinct human species
(‘hominids’), modern Homo sapiens and the apes. “Great apes” are 2
species of chimpanzee, the orangutan and the gorilla, and “Lesser
apes” are 7 species of gibbon.
Old-world monkeys: (Cercopithecoidea or Catarrhines) = dozens of
species e.g. rhesus and other macaques, vervets and baboons.
New-world monkeys: (Ceboidea or Platyrrines) = dozens of species
e.g. cebus, squirrel, spider and owl monkeys and marmosets.
Similarities in primate lifespans
Table of Primate Life-Spans (After Jolly, 1972: p. 6 of handout)
Life
spans
Species CEBUS RHESUS GIBBON ORANG CHIMP GORILLA Homo
(New
(Old
(Lesser
World
World
Ape)
Monkey) Monkey)
(Great
Ape)
(Great
Ape)
(Great
Ape)
Sapiens
sapiens
Days
Gestation
180
168
210
275
225
265
266
Total yrs
30+
28+
29+
30+
40+
35+
70+
Sub
Adult yrs
4.0
7.5
8.5
10.5
10.0
11.0
20?
Infancy
yrs
0.5
1.5
2.0
3.5
3.0
3?
6?
%
13%
Subadult
27%
29%
35%
25%
31%
29%
%
Infancy
5%
7%
12%
8%
9%
9%
2%
Similarities in brain anatomy
T.H. Huxley (1863, 1874)
“So far as cerebral structure goes therefore,
it is clear that man differs less from the
Chimpanzee or the Orang, than these do
even from the monkeys, and that the
difference between the brains of the
Chimpanzee and of Man is almost
insignificant, when compared with that
between the Chimpanzee brain and that of
a Lemur. “(Darwin, 1874/1901, p. 312)
‘Every principal gyrus and sulcus of a
chimpanzee’s brain is clearly represented in
that of a man’.
Human brain
Chimpanzee
brain
The chimpanzee
brain is only
about a third the
size of a typical
human brain, but
superficially
looks similar
Mammal and primate brains
Huxley’s comparisons
“So far as cerebral structure goes therefore, it
is clear that man differs less from the
Chimpanzee or the Orang, than these do even
from the monkeys, and that the difference
between the brains of the Chimpanzee and of
Man is almost insignificant, when compared
with that between the Chimpanzee brain and
that of a Lemur. “(Darwin, 1874/1901, p. 312)
Semendeferi abstract
Asymmetry in Broca’s
Area
(Cantalupo and
Hoplins, 2001)
Similarities in DNA
Diamond (1992)
3rd
Chimpanzee
Human DNA is
98.4% the same as
that of the
chimpanzee
mouse
Chimp genome dec 10 2003
DNA similarities
•
•
•
•
•
•
•
•
human to yeast about 30%
Main source:
human to worm about 40%
http://genome.pfizer.com/
human to fruit fly about 60%
human to mouse about 90%
human to rhesus monkey about 93%
human to chimp about 98.4%
human to human about 99.9%
identical twins, 100% identical
Tree from enard functional genomics
Common ancestor
Similarities in facial expression
Many
expressions
mouth face
Emotional expression
“tense-mouth face”
Emotional
expression 2
Emotional
expression 3
“Open mouth
threat”
Open
mouth
(Facial expressions
taken from Jolly,
1972)
Preadaptations for tool use
Stick play
overarm
Kohler, 1925:
Gleitman 1999 p.
159;
2004, p. 158
Climbing poles menzel
Sticks as weapons
Tool use in wild chimpanzees
• Since 1987 in Guinea in West Africa,
observations have been being made in the
centre of free-range area, where experimenters
provide stones and nuts. Infants under 3.5
years old do not crack nuts themselves
• Inoue-Nakamura, N, & Matsuzawa, T (1997)
Development of stone tool use by wild
chimpanzees (Pan troglodytes). Journal of
Comparative Psychology, Vol.111, No.2,
Pp.159-173.
Use of
tools
African Oil Palm
Has fruits about the size of a plum,
which occur in very large bunches
weighing up to 20 kilos.
Tool use in wild chimpanzees
Nut cracking consists of the following actions:
•
•
•
•
•
(a) picking up a nut
(b) putting it on an anvil stone
(c) holding a hammer stone
(d) hitting the nut with the hammer stone
(e) picking up and eating the nut kernel.
Tools (Bossou)
Tool use in wild chimpanzees
• The individual actions of ‘Take’, ‘put’ ‘hold’, ‘hit’
and eat, had all been performed by 1.5 yrs
• At 2.5 they often put a nut on a stone, hit it with the
back of their hand, then picked up a kernel from
somewhere else or scrounged a kernel from their
mothers
• Holding the hammer was the a difficult part –
chimps never hit nut with the hammer stone until the
last stage
Tool use in wild chimpanzees
Discussion
• “True imitation cannot explain the results of
the present study”
• As the present results suggest, they learned the
general functional relations of stones and nuts
• and also learned the goals obtained by the
demonstrator
• This learning process might be called
emulation
Tools group at bossou
Termite fishing
Home rearing studies
Kelloggs (1933)
Arm strength
Revolver
Spoon Gua
Gua several
Ready for bed
tickling
Walking together image
Walking together image and text
Primate Cognitive Superiority?
• An extreme case of this notion was the
expectation that, with sufficient training, infant
apes would develop linguistic competence. (E.g.
Gardner and Gardner, 1969).
• There is now a wide consensus that what
chimpanzees achieve, even after years of
training, merely emphasizes the importance of
inherited human specialized capacities.
Attempts at Language Training
Method
Names of chimps
Names of
psychologists
Gardner and
Gardner (1969)
SavageRumbaugh
Terrace et al,
1979
American Sign
Language (ASL)
Washoe,
Austin &
Sherman
Kanzi
Nim Chimpsky
Plastic tokens
Sarah (& others)
Premack (1971,
‘76 & ‘86)
“Lexigrams”:
visual symbols
on a screen
Austin &
Sherman, +
others
Greenfield and
SavageRumbaugh (1993)
Pause
Vicki imitating
Vicki (Hayes &
Hayes, 1951)
Vicki (Hayes & Hayes,
1951)
Vicki (Hayes & Hayes, 1951)
• Vicki died when 7
• Lots of imitation, throws and catches balls, cuts
paper with scissors, opens doors, flips light switches
• At 5.5 spontaneous sorting of e.g. nuts bolts screws
and washers without error
• Conclusion was that Vicki had rudimentary higher
mental functions
• But she had only 4 “spoken words” mama, papa up
and cup plus 3 spontaneous sounds
pause
Nim 1 p. 7
Terrace, H.S. (1979/1980) Nim. London:Eyre Methuen.
Terrace, H.S., Pettito, L.A., Sanders, R.J. and Bever, T.G.
(1979) Can an ape create a sentence? Science, 206,
891-902.
The project lasted 4 years and involved 60 teachers,
mostly volunteers. Another group of about 40 volunteers
tabulated and analyzed data from daily records and
videotapes.
In the Science paper more than 19,000 “multi-sign
utterances” were analyzed for syntactic and semantic
regularities.
Nim p. 393 hug (1999, not in 2004)_
Nim p. 393 apple (1999, not in 2004)
Nim with cat
Nim’s happy face
Washing up
Nim 1 p. 7
Terrace, H.S. (1979/1980) Nim. London:Eyre Methuen.
Terrace, H.S., Pettito, L.A., Sanders, R.J. and Bever, T.G.
(1979) Can an ape create a sentence? Science, 206,
891-902.
The project lasted 4 years and involved 60 teachers,
mostly volunteers. Another group of about 40 volunteers
tabulated and analyzed data from daily records and
videotapes.
In the Science paper more than 19,000 “multi-sign
utterances” were analyzed for syntactic and semantic
regularities.
Nim 2 p. 7
There were some regularities, but videotape analyses
showed that most of Nim’s utterances were prompted by
his teacher’s prior utterances (signs in American Sign
Language).
Nim interrupted his teachers to a much larger extent
than a child interrupts an adult’s speech.
Nim 3 p. 7
Typical two-sign combinations were —
“play me” (375)
“tickle me” (316)
“hug Nim” (106)
“tickle Nim” (107)
----“more eat” (287)
-----“banana Nim” (73)
“in pants” (70)
Nim 4 p. 7
Typical three-sign combinations were —
“play me Nim” (81)
“eat me Nim” (48)
“eat Nim eat” (46)
“tickle me Nim” (44)
“grape eat Nim” (37)
“banana Nim eat” (33)
“Nim me eat” (27)
“banana eat Nim (26)
“eat me eat” (22)
Typical four-sign combinations were —
“eat drink eat drink” (15)
“eat Nim eat Nim” (7)
“banana Nim banana Nim” (5)
“drink Nim drink NIm” (5)
“banana eat me Nim” (4)
“banana me eat banana” (4)
“banana me Nim me” (4)
“grape eat Nim eat” (4)
“Nim eat Nim eat”
“play me Nim play”
“drink eat drink eat” (3)
“drink eat me Nim” (3)
Nim 5 p. 7
Washoe 2000
• Jensvold, M. L. A., & Gardner, R. A. (2000).
Interactive use of sign language by cross-fostered
chimpanzees (Pan troglodytes). Journal of
Comparative Psychology, 114(4), 335-346.
• NB. an ’X’ following a sign indicates an immediate
repetition of the sign; a ‘?’ indicates an ASL version
of questioning inflection, and a ‘/’ indicates the ASL
inflection corresponding to the end of an utterance.
Washoe 2000
•
•
•
•
•
•
•
•
•
Trial #3 (page 337) Example 1 in lecture
1:04:35 Washoe: ME GIMMEX/
1:04:40 Probe 1: questioning expression
1:04:41 Washoe GIMME/
1:04:49 Probe 2 WHAT?/
1:04:51 Washoe MEX GIMMEX/
1:04:54 Probe 3 NOT UNDERSTAND?
1:04:56 Washoe FOOD GIMME/
End of trial
Washoe 2000 - 2
•
•
•
•
•
•
•
•
•
Trial #5 (page 338) Example 2 in lecture
0:08:46 Washoe: FRUIT GIMMEX/
0:08:49 Probe 1: WHO FUNNY?
0:08:51 Washoe ROGER/
0:08:54 Probe 2 WHERE CAT?/
0:08:56 Washoe ROGER GIMMEX/
0:09:03 Probe 3 WHERE CAT?
0:09:05 Washoe GIMMEX/
End of trial
“Conversations” 2002
• Bodamer, M. D., & Gardner, R. A. (2002). How
cross-fostered chimpanzees (Pan troglodytes) initiate
and maintain conversations. Journal of Comparative
Psychology, 116(1), 12-26
• NB. an ’X’ following a sign indicates an immediate
repetition of the sign; a ‘?’ indicates an ASL version
of questioning inflection, and a ‘/’ indicates the ASL
inflection corresponding to the end of an utterance.
“Conversations” 2002 - 2
•
•
•
•
•
•
•
•
Tatu: PERSON TIME/
Probe 1: WHAT?/
Tatu: FOOD TIME
FOOD TATU/
2. “On topic”.
Example
Tatu: TIME/
Probe 2: WHAT TIME?/
Tatu: FOOD TIME FOOD/
Mental attribution and “Theory of Mind”
• Self-recognition in mirrors seems to only
occur in apes.
• It is suggested that this indicates a broader
capacity for introspection and for attributing
mental states to other individuals (Gallup et
al, 1995; Boysen and Himes, 1999).
• Povinelli (1993) reviews this suggestion, but
others such as Heyes (1998) are sceptical
even about self-recognition.
Self recognition (?) in mirrors
Mirror tongue
Mirror 3
Povinelli 97 abstract
Povinelli et al (1997)
mirror theory
Povinelli et al (1997)
mirror data
Imitation (?)
Cultures?
Whiten, A., Goodall, J.,
McGrew, W. C., Nishida, T.,
Reynolds, V., Sugiyama, Y.,
Tutin, C. E. G., Wrangham,
R. W., & Boesch, C. (1999).
Cultures in chimpanzees.
Nature, 399(6737), 682-685
Conclusion p.4 of handout
• Many aspects of human cognition are
unique.
• The capacity for language is one of the
most important.
• Other aspects of human cognition,
such as object recognition, may be
found in many other species.
• Many authors believe that the great
apes, particularly chimpanzees, exhibit
more human-like cognition particularly
in the area of social learning.
Intranet
Look under timetable
But none of the illustrations
from any of the Gleitman
texts, and very few from
elsewhere are included for
reasons of copyright.
Online handouts