Transcript the file for both lectures - s-f

Psychology BSc –
General Foundations Module
Evolution and Psychology
Dr Stephen Walker
January 11, 2007
Aims and Objectives
• Aims: These two lectures aim to refresh students’
knowledge of the theory of evolution, or to introduce
them to it, and to introduce them to aspects of
psychology which have been influenced by
evolutionary approaches.
• Objectives: By the end of the lectures the students
should:
• know the general outlines of the theory of evolution
and the time course of human evolution
Objectives continued
• be able to answer correctly a majority of the questions on
the self-assessment test included in the handout
• understand some of the key differences between nativist
and empiricist theories in psychology
• be aware of the sections of the course text (Gleitman,
1999/2004) where evolutionary approaches are applied
to perceptual, cognitive, emotional and social aspects of
psychology.
Topics to be covered
The theory of evolution
What Darwinians say about
psychological topics
Schools of thought influenced by
Darwinian approaches
Areas of psychology that have been or
could be influenced by these approaches
Format of lectures
There will be a very brief coverage of a
large number of areas
The question addressed is a general one:
what is the relevance of evolution for
psychological topics?
The answer to be given is in terms of the
‘nature/nurture’ issue.
Topic and essay question
“Does the theory of evolution have any
relevance for psychological topics?”
Gleitman’s textbook mentions evolution, or
evolutionary theorists, or “biological bases”
in several places.
So to that extent evolution must be relevant
for psychological topics, although —
Culture vs. Evolution
• Gleitman et al. (1999, page 436) agree that it is
arguable that human social behaviour is “so
thoroughly infused by culture” that comparisons
with the Darwinian influences on animal
behaviour are fruitless.
• “…there is no question that human social
behavior is flexible and subject to cultural
learning in ways that other species’ behaviour is
not….. (Gleitman et al, 2004; p. 458)
Basic Reading see p. 1 of handout
Basic Reading (page 1 of handout)
Gleitman et al., (2004) Psychology 6th edition, or Gleitman et al., (1999) Psychology 5th edition, or
Gleitman, (1995) Psychology 4th edition.
Page
Page
Page reference Textbook Heading
reference in
reference in
in Gleitman
Gleitman et al Gleitman et al 1995
2004
1999
see 416-7
406-9
380-83
“Natural Selection and Survival”
5-6
3-4
3-4
“Displays”
152-4
152-4
141-2
“Differences in what different species learn”
197-201
192-7
175-180
“Evolution and sensory equipment”
338-342
373-4
350-1
“The growth of language in the child”
353-357
390-4
367-375
“The critical period hypothesis & Language in nonhumans”
416-417
405-37
379-413
“The biological roots/basis of social behaviour”
451-458
476-81
443-448
Emotions and facial expression
438-440
494
455-6
“Reciprocal altruism”/“The roots of reciprocity”
478-484
552-7
511-6
“What is the cognitive starting point?”
506-510
576-9
534-7
“The roots of attachment.”
632-634
747-50
702-5
“The sociocultural perspective”
Topics to be covered
• I will look first at the analysis of instinctive
behaviour in animals (ethology)
• Then I will cover theoretical arguments about
assuming innate capacities in human psychology
(Pinker, 1984, 2003)
• In the second lecture I will briefly outline the time
course of human evolution (not in Gleitman)
• — and also review the material in the textbook
which supports the existence of innate biases in
the perceptual, cognitive and emotional worlds of
human infants
Darwin in
Gleitman et
al. 1999
p. 406
&
2004
p. 416
All Darwin’s publications are freely available online at http://darwin-online.org.uk
The Theory of Evolution
Resources are not unlimited
Some individuals will flourish more than
others and produce more offspring
There are inherited differences between
individuals, with some random changes
Natural selection occurs if a population
changes over generations because of this
(see e.g. Dawkins, 1995)
Evolution — II
• The first point about evolution is that it connects
the human species with the rest of the animal
kingdom,
• However, it is also possible and indeed likely that
the course of human evolution has led to humans
being uniquely different from all other currently
living species
Common pattern for body plans: standard biology texts
EVOLUTIONARILY CONSERVED MOLECULAR GENETIC MECHANISMS FOR
PATTERNING THE EMBRYONIC BRAIN.
Reichert & Simeone (2001)
Fly mutant
restored
with human
gene
Fly mutant
restored with
mouse gene
Mouse mutant
restored with
fly gene
What Darwinians say about Psychological
topics
Darwinians emphasise innate or “built-in”
factors in psychology
They tend to emphasise nature rather than
nurture and are “nativists” rather than
“empiricists”
They are often interested in development
during an individual’s life-span
Darwinian Schools of Thought (p 2 of handout)
Ethology: scientific study of innate
factors in animal behaviour (N. Tinbergen
and K. Lorenz, Nobel Prize, 1973)
Sociobiology: as above, but emphasis on
social behaviour (E.O. Wilson, 1975)
Evolutionary Psychology: emphasis on
the effects of human evolution on human
psychology (Tooby and Cosmides, 1992;
Pinker, 1994, 1998, 2002/3)
Pause before weaver bird next
Examples of natural selection in animal behaviour
I am
going to
very briefly
at animal
− instincts
or look
“genetically
determined
behaviour
patterns”
behaviour.
It is clearly not contentious to
give evolutionary explanations for animal
behaviour, but such explanations are not
always completely obvious. But for
questions such as “why do birds build
nests?” there is not a problem.
Gleitman, 1999, p. 407.
Weaverbird nest:
“Many (?) animals have
genetically determined
behavior patterns
characteristic of their
species.”
Gleitman, 2004, p.418.
Bowerbird nest. “..natural
selection will lead to an
evolution of how animals
behave..” (p. 417)
Ethological analyses of animal behaviour
Pecking 1
“Supernormal Stimulus”
Gleitman, 1999
p.409
1995, p. 382
Not in Gleitman et
al. 2004
Supernormal stimulus defined
Supernormal stimuli
Fig 3.8 in Manning and Dawkings
(1992) p. 52
Supernormal
stimuli − 2
Supernormal stimuli − 3
Morrison, D. S., & Petticrew, M.
(2004). Deep and crisp and
eaten: Scotland's deep-fried
Mars bar. Lancet, 364(9452),
2180-2180. (not on list)
We did a telephone survey in
June, 2004, of random selection
of the 627 fish and chip shops in
Scotland …….. 66 shops sold
deep-fried Mars bars
…….we did also find some
evidence of the penetrance of
the Mediterranean diet into
Scotland,
…. albeit in the form of deepfried pizza
More animal behaviour in Gleitman et al.
Gleitman et al (2004) page 508
Lorenz walking
Built-in social behaviour p. 408, 1999 not in 2004
Gleitman, 1995, p. 400
1999, p. 427
Parental feeding
11. 6 Innate triggers In many species, the
parents’ care-taking behaviors are elicited by
specific signals from the young. (Gleitman,
2004; p. 430)
Cuckoos
Gleitman, 1995, p. 400
1999, p. 427
Not in 2004
Mentioned by Darwin (1859)
Cuckoos − one of Darwin’s examples
Evolutionary Psychology
• Darwinian theory helps explain the
behaviour of cuckoos, and almost all other
animal species, but does it explain human
behaviour in the same way?
• One example follows of an evolutionary
prediction for human behaviour which turns
out to be wrong.
Kenrick et al, 2003
Psychological Review, 110(1), 3-28
“At the most general level, evolutionary
psychology can be defined as the study of
cognitive, affective, and behavioral mechanisms as
the solutions to recurrent adaptive problems.”
“Along with the morphological features designed
by natural selection, organisms also inherit central
nervous systems……The behavioural inclinations
of a bat would not work well in the body of a
dolphin or giraffe and vice-versa.”
Kenrick et al. wrong
• over a period of 35 years in Sweden (19651999), there was no overall overrepresentation of stepchildren as victims.
• (Temrin, Nordlund, & Sterner, 2004)
• In families with both stepchildren and
children genetically related to the offender,
genetic children tended to be more likely to
be victims.
Areas of psychology influenced- see top of p. 3 and
p. 6 of handout
Animal psychology has been most
influenced (ethology & sociobiology)
Psychologists interested in human language
and perception now point to innate
mechanisms (Pinker, 1994)
Social psychologists appeal to cultural
influences and are generally against innate
factors (Harre, 1986)
Review of innate influence in areas of human psychology (p3 on
handout)
Perceptual systems: vision; colour vision
(olfaction: 2004 Nobel). Also motor systems,
and eye-hand co-ordination.
Cognitive systems: built-in concepts of time,
space and physical reality; the bioprogram for
1st language learning
Emotionality: facial expressions as displays
Social systems: bioprograms for social
interaction? (Tomasello et al, 1993)
Social systems: extra comments (p3)
human intelligence may have evolved
because of its importance in social
interaction, especially to cope with social
exchange rules (Gleitman et al., 1999; p.
494 | 2004; p. 440)
natural inclinations are not necessarily
desirable: cultural systems may have often
developed to supplant them (Hobbes, 1651;
Gleitman, 1999, p. 405 & p. 437; Gleitman,
2004, p. 612)
Thomas Hobbes (1651)picture in Gleitman, 1999; p. 406 |
text in 2004 edn p. 612
pause
e next slide is 2x2 on page 7
obbes is useful as an example of syaing that the “state of
ture is not where we are now, but nativists would say he
s wrong about the original human state being solitary
en though stone age life was probable more brutal and
ort in general than it is now
2x2
(page 7 of handout)
PinkerCover
(1994, 1998,
2003) − an example of an
evolutionary
psychologist
Pinker, S. (1994) The Language Instinct.
pp 419-20.
• “So what are the modules of the human mind?”
• “Using biological anthropology, we can look for
evidence that a problem is one that our ancestors
had to solve in the environments in which they
evolved —
• so language and face recognition are at least
candidates for innate modules, but reading and
driving are not.”
Genes and Language:
• Psycholinguists such as Noam Chomsky
and Steven Pinker have been convinced
since the 1960’s that the human capacity for
language capacity is innate.
• In the last six years, particular genes
involved with language capacity have been
discovered. (Not covered in Gleitman et al.)
Genes and
Language: BBC
October 01
Pinker comments October 2001
From the Wellcome Trust web pages
National Geographic
Mice 05 foxp2
N
see Gleitman et al 1999, p. 40 /2004, p. 60, for human cerebral
lateralization which is associated with language capacities
Sun, T., & Walsh, C. A. (2006). Molecular approaches to brain
asymmetry and handedness. Nature Reviews Neuroscience, 7(8),
655-662
Pinker, S. (1994) The Language
Instinct. pp 419-20.
• if there is a module for it, a task should seem
easy, and we ought to be able to discover a
subsystem of the brain that is responsible for it.
• Pinker gives a long list of possible innate modules
including:
1.Intuitive mechanics: knowledge of objects
2.Intuitive biology: understanding of how plants and
animals work.
3.Number.
Pinker 2003, p.46
Gleitman, 1999,
p.698
Gleitman, 2004,
p.605
15,000 UK twins
currently being
studied, MRC
funded (TEDS −
Twins early Development
Study
Separated twins
Separated at birth, the Mallifert twins meet
accidentally…..
Pinker, S. (2002) The Blank Slate
• p. 35. “This is not to say that cognitive scientists
have put the nature-nurture debate completely
behind them: they are still spread out along a
continuum…..”
• p. 31. “The first bridge between biology and
culture is the science of mind, cognitive science.”
• p. 60. Take the case of a person’s mother tongue,
which is a learned cultural skill par
excellence….The innate endowment for language
is in fact an innate mechanism for learning
language.
pause
End of lecture 1
ween pinker and Robert winston, but is also the start of
lution, which is not really discussed by Pinker or other
. And is not in Gleitman and the details can be ignored
a very broad brush view. It changes because of new fossils
good agreement about the broad timescale which you
ge 8 (not in Gleitman but the Grant to Robin Dunbar
there is a connection between knowledge of human
nd evolutionary psychology
Psychology BSc –
General Foundations Module
Evolution and Psychology — Lecture 2 Human
Evolution and Human Infancy
Dr Stephen Walker
January 11, 2007
Bottom of page 8 of handout
Millions bottom
Top of page 8 of handout
Millions top
“Lucy”
Family Tree: from Johanson’s site “Becoming Human”
Lucy to Language
Book by Johanson and Edgar −2 copies in Main
Birkbeck Library, classmark=599.938 JOH − listed
on p. 1 of handout.
Australopithecus afarensis
Fossilized footprints,
discovered by Mary Leakey
in Laetoli, Tanzania.
They are dated at 3.5 Mbp,
and only the “Lucy” species
is known from that time, but
the imprints look very like
modern human imprints.
A new early fossil (2006)
Alemseged, Z., et al. (2006). A juvenile early hominin
skeleton from Dikika, Ethiopia. Nature, 443(7109), 296-301
Dikika is only 4km from where ‘Lucy’ was
found (Australopithecus afarensis )
The Dikika specimen, from 3.3m yrs ago was
about 3yrs old and probably female.
The legs were human-like for bi-pedal
walking, but the arms and hands ape-like.
The hyoid bone (for the larynx) was also
ape-like
Napier chimp grip
Chimpanzees and
other apes can hold
small objects, but
have lost, or never
had, the opposable
thumb
New Neanderthal data: Green et al., (2006)
• Suggests common ancestor ~450,000 yrs ago
British Psychological
Society news magazine, the
Psychologist, August, 2001
see p. 4 for url
(http://tinyurl.com/y6qs9e)
Psychologist cover
Boxgrove,
West Sussex,
500,000
years before
the present.
Excavations
funded by
Boxgrove
English
Heritage.
Dept of
Archaeology,
University
College
Stone tools provide some evidence about prehistoric
human activities
Oldowan tools >2m years
“Even 2.34m years ago there was a highly controlled technology for
producing stone flakes following constant technical rules and
resulting in high productivity.” (Delagnes and Roche, 2005: not on list)
Acheulian tools
1.5 m – 0.2 m yrs,
mainly Homo
erectus.
Handaxes and
choppers
Size of Handaxes
“Mousterian”tools, 200k
yrs ago – 30k. Included a
wider variety of flake
tools. (used by
Neanderthals)
Neanderthal hut
Mammoth remains
Approx 25 k
years ago,
modern homo
sapiens used a
wide variety of
weapon heads
and “microlith”
stone blades
Microliths
Endscraper
Piercer or
“hand-drill”
“spokeshave”
“Modern” Homo sapiens, approximately 25,000 years ago
knifepoint
Cave paintings do not go back as far as stone tools, only about as far
as the most recent ones just shown, but demonstrate that capacities
similar to those of current humans existed many millenia before the
development of agriculture about 11 thousand years ago.
Chauvet fur clad
Chauvet (31k) bison with active legs
Detail of horses at Chauvet (31k)
Rhinos at Chauvet (31k)
Hand at Chauvet (31k)
Hands in Cave at Cosquer
29K
27K
Lamp at Lascaux (13k)
Bull at Lascaux (13k)
Cattle at Lascaux (13k)
Bison bellowing at Altamira (13k)
Honey gathering (Bicorp, Spain, 6K)
End of evolution, start of Gleitman
Next, evidence from human infancy in
Gleitman et al., mainly in the areas of visual
perception, language learning and facial
expression
essage of human evolution is that it produced very
ount of blank space on the human slate. We did not
cts for making stone stools, but a general purpose
nd cultural innovation
not a completely blank slate since we are born with
s, biases and capacities
What is the cognitive starting point?
• “Very young infants begin life with
primitive concepts of space, objects,
number, and even the existence of other
minds.” (Gleitman, 1999, p. 552; 1995, p.
511; 2004, p. 479)
• E.g. depth perception in the “visual cliff”.
Visual
Cliff
Gleitman
1999, p.
553; 2004,
p.5
Visual
Cliff
Gleitman
1999, p.
553; 2004,
p.5
Occlusion
1999, p. 553
2004, p. 479
Occlusion
1999, p. 553
2004, p. 479
Occlusion
1999, p. 553
2004, p. 479
Baby habituation
1999, p. 554
Baby habituation
Baby habituation
Occlusion in 4month olds
1999, p. 554
2004, p. 480
Occlusion
1999, p. 554
2004, p. 480
Number in infancy 1999, p. 557 | 2004, p. 483
Starkey, et al., 1983)
Csibra web page
Csibra first
Csibra second
Nine- and twelve-month-old babies look longer at the scene on the
left, so they see it more different from the previous one. Why? After
all, the jumping movement pattern of the ball is more similar to the
previous scene than the straight motion.
Csibra control
But jumping without an obstacle does not make sense if the goal is
simply to reach a position. Indeed, the red ball in the right scene acts in
a more sensible way, therefore it seems more similar to the previous
scene.
This conclusion is supported by the fact that if the babies first see the
ball hopping without reason (top), they do not prefer any of the scenes
above.
Csibra duck
Csibra, G. (2001). Illusory contour figures are perceived as
occluding surfaces by 8-month-old infants. Developmental
Science, 4, F7-F11. (not listed in handout)
Pause before language in Gleitman
Sections of Gleitman et al., on Language
Acquisition in Human Infants
Language learning can proceed despite severe
environmental deprivation.
This supports the contention that the mental
machinery for language is innate. (Gleitman et al.,
1999, p. 390 / 2004, pp 350-352)
“….language is an irrepressible human trait: deny it to the
mouth and it will dart out through the fingers” (Gleitman
et al., 2004; p. 350 − in relation to American sign
language, used by the deaf)
Helen Keller
conversing with
Eleanor Roosevelt:
1999, p. 390.
“Learning
language requires
a receptive human
mind”, Gleitman
et al. 1999 p. 374
— 2004, p. 352.
Between the ages
of 2 and 5 infants
learn several new
words each day
(2004; p. 338)
Word meaning at the one word stage: 1999,
p. 375; 2004, p.342
Sections of Gleitman et al., and other
sources relating to emotional expresion
Evolution of smiling p. 429
1999, not in 2004
Evolution of smiling p. 429
1999, not in 2004
Evolution of smiling p. 429, 1999
not in 2004
“Face” recognition in newborns p. 557-8, 1999,
and p.484, 2004
Newborn infants have a predisposition to look at face-like
objects. (41 newborns at University College Obstetrics
Department between 15 and 69 minutes after birth)
Smiling in
those born
blind: only in
Gleitman,
1995; p. 403
not in 1999 or
2004
blunkett
Peleg et al. (2006). Hereditary family signature of
facial expression. PNAS 103(43), 15921-15926
• Correlated facial expressions in congenitally blind
subjects and their seeing relatives, anticipates
genes.
Darwin’s “Expression of the
Emotions”
• See “The universality of
emotional expressons, p. 451,
Gleitman et al. (2004
Darwin’s “The expression of the emotions in
man and animals” (1872)
All Darwin’s publications are freely available online at http://darwin-online.org.uk
Darwin’s
cats
Darwin’s dogs
Darwin’s babies
Darwin terror and
horror
Quotes from Archer (2001) “Evolving theories
of behaviour”
see p. 4 for url(http://tinyurl.com/y6qs9e)
“… a single unifying starting point for
understanding why we think and behave as we do
today: natural selection has made us this way”. (p.
414)
“A ‘sweet tooth’ is adaptive when sugar is
relatively rare, but not in present conditions when
sweet foods are constantly available.” p. 417.
“The fight –and-flight response is adaptive for
responding actively to predators, but not when
trapped in a traffic jam.” p. 417.
Quotes from Segal (2001) “Main agendas and
hidden agendas”
see p. 4 for url(http://tinyurl.com/y6qs9e)
“Yes, the human species evolved and has survived;
but natural selection made us in what way, exactly?”
(p.422)
 “In the UK in the 1990s, women overall delayed
giving birth until their thirties. The proportion of
women remaining childless increased steadily over
recent decades.” ( p 412)
“What millions of years of genetic change have
actually produced is the potential for human cultural
invention.” (p.423).
Review of innate influence in areas of human psychology
(p3 on handout)
Perceptual systems: vision; colour vision
(olfaction: 2004 Nobel). Also motor systems,
and eye-hand co-ordination.
Cognitive systems: built-in concepts of time,
space and physical reality; the bioprogram for
1st language learning
Emotionality: facial expressions as displays
Social systems: bioprograms for social
interaction? (Tomasello et al, 1993)
Conclusion (p. 4 of handout)with added bullet points
Darwinian evolution has shaped many aspects
of human cognition
starting with the capacities of our perceptual
systems
and arguably including higher-order aspects
of cognitive and emotional biases.
But biologically based predispositions do
little to diminish the profound role of cultural
and historical influences on uniquely human
intellectual achievement and social diversity