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) P sychology 4th edition.
Textbook Heading Page reference in
Page reference in
Gleitman et al Gleitman et al
Page reference in Gleitman
1995
2004 see 416-7
5-6
1999
406-9
3-4
380-83
3-4
152-4
197-201
338-342
353-357
416-417
451-458
438-440
478-484
506-510
632-634
152-4
192-7
373-4
390-4
405-37
476-81
494
552-7
576-9
747-50
141-2
175-180
350-1
367-375
379-413
443-448
455-6
511-6
534-7
702-5
“Natural Selection and Survival”
“Displays”
“Differences in what different species learn”
“Evolution and sensory equipment”
“The growth of language in the child”
“The critical period hypothesis & Language in nonhumans”
“The biological roots/basis of social behaviour”
Emotions and facial expression
“Reciprocal altruism”/“The roots of reciprocity”
“What is the cognitive starting point?”
“The roots of attachment.”
“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 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

Gleitman, 1999 p.409
1995, p. 382
Not in Gleitman et al. 2004
“Supernormal Stimulus”

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)

Gleitman, 1995, p. 400
1999, p. 427
Not in 2004
Mentioned by Darwin (1859)
Cuckoos

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 (1965-
1999), 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
The next slide is 2x2 on page 7
Hobbes is useful as an example of syaing that the “state of nature is not where we are now, but nativists would say he was wrong about the original human state being solitary even though stone age life was probable more brutal and short in general than it is now

(page 7 of handout)
2 x 2

Cover
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

Nature 2002
•

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.

Separated twins
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 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
This is between pinker and Robert winston, but is also the start of human evolution, which is not really discussed by Pinker or other evol psych. And is not in Gleitman and the details can be ignored apart from a very broad brush view. It changes because of new fossils but there is good agreement about the broad timescale which you have on page 8 (not in Gleitman but the Grant to Robin Dunbar shows that there is a connection between knowledge of human evolution and evolutionary psychology

Psychology BSc –
General Foundations Module
Evolution and Psychology — Lecture 2 Human
Evolution and Human Infancy
Dr Stephen Walker
January 11, 2007

Millions bottom
Bottom of page 8 of handout

“Lucy”
Top of page 8 of handout
Millions top

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
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)

29K
Hands in Cave at Cosquer
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
The most general message of human evolution is that it produced very large if not infite amount of blank space on the human slate. We did not develop fixed instincts for making stone stools, but a general purpose ability for learning and cultural innovation
But we are certainly not a completely blank slate since we are born with existing concepts, 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)

Meadow of Indiana
University, Bloomington, Indianahave carried out the amount, rate and type of gestures used by two
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