Psychology 3228
Evolution and Psychology
CLASS NOTES: Unit 3
Video
3.1
3.2
Topic
Antecedents to
“Evolutionary Psychology”
Emergence of
Behavioural Ecology and
Sociobiology
3.3
Evolutionary Psychology
and the SSSM
3.4
Interview with Tooby and
Cosmides
Criticisms of Evolutionary
Psychology
3.5
3.6
3.7
3.8
3rd Edition
box 1.2
4th Edition
box 1.2
pp. 20-25:
EO Wilson and
sociobiology
From sociobiology to
evolutionary
psychology
Box 1.3
pp. 15-19: The rise of
culture…
Cultural relativity
n/a
Box 1.3
pp. 16-18: From
sociobiology to
evolutionary
psychology
pp. 29-33:
Agreement and
disagreement…
to end of chapter
Different Approaches to
pp. 20-25:
Evolution and Human
EO Wilson and
Behaviour
sociobiology
From sociobiology to
evolutionary
psychology
Development as a Central pp. 124-129
Process
start of ch 5 through
epigenetic landscape
Heritability and
pp. 50-51
inheritance
Heritability of
characteristics
pp. 11-15: The rise of
culture…
Learning theory…
n/a
pp. 23-26:
Agreement and
disagreement…
to end of chapter
pp. 16-18: From
sociobiology to
evolutionary
psychology
pp. 113-119
start of ch 5 through
epigenetic landscape
pp. 42-44
Heritability of
characteristics
LECTURE NOTES
Psychology 3228
Evolution and Psychology
Unit 3
Evolutionary Approaches to Human Behaviour
Development as a Central Process
Antecedents to “Evolutionary Psychology”
Unit 3.1
Development of Evolutionary Psychology
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Evolutionary Theory developed primarily in regard to non-human animals
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•
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Animal Behaviour / Ethology
Behavioural Ecology
Sociobiology
influenced rise of Human Behavioural Ecology and Evolutionary Psychology as “new”
approaches
Animal Behaviour
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historically, studies of animal behaviour was divided between two approaches
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North America
primarily psychologists
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Europe
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ethologists- animal behaviourist
Early 20th century
Ethology
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•
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•
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mostly Europe
field studies
wild animals
“innate” behaviour and species-specific learning
natural history
Comparative Psychology
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•
•
•
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mostly North America
lab studies- general behavious
lab animals
general laws of learning thought to apply to all species
model systems
Ethology
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study of animal behaviour
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primarily natural behaviours, often studied in the field
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description and field experiments
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interest in stimuli controlling behaviour, innate behaviours, imprinting, evolution of
behaviour
1973 Nobel Prize in Physiology/Medicine
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Karl von Frisch
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Konrad Lorenz
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Nikolaas Tinbergen
Comparative Psychology
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for much of 20th century Comparative Psychology was dominated by Behaviourism
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sought to understand general laws of learning
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e.g. B.F. Skinner
Tinbergen
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Established “Four Questions” approach to study of Behaviour
Non historical and proximate: mechanism (causation)
Historical and proximate: development (ontogeny)
No historical and ultimate: survivall value (function)
Historical and ultimate: evolution (phylogeny)
Animal Behaviour
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Ethology (as a term) has generally been replaced with “Animal Behaviour” (though
some of us still like the term Ethology)
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some researchers bridged approaches between Comparative Psychology and ethology
Charles H. Turner
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American Zoologist/ Comparative Psychologist
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pioneered integrative studies of animal behaviour of insects and other animals
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first demonstrated hearing and associative learning in insects
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seminal work on brain and behaviour
Emergence of Behavioural Ecology and Sociobiology
Unit 3.2
Sociobiology
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seminal book by E.O. Wilson 1975
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evolution of social behaviour
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human behaviour explicitly included
gave rise to fields such as evolutionary psychology
controversy around topics such as infanticide, mate choice etc.
Behavioural Ecology and Sociobiology- same thing
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evolution has resulted in animals being optimized to their environment
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use ecological theory and economic models to predict behaviour and evolution of
behaviour
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foraging, optimality models
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costs and benefits
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currency = reproductive success
Behavioural Ecology and Sociobiology
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example: Optimal foraging models
Behavioural Ecology and Sociobiology
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Behavioural Ecology approaches quickly came to dominate ethology, as well as some
comparative psychology
Predictions by E.O. Wilson
Wilson’s Predictions: thought ethology and comparative pscyh would go away and in 2000s
most research would be dome by physiology and sociobiology
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failed to take into account integration between proximate mechanisms and
ecological/evolutionary influences
The Study of Behaviour- there has been changes
Criticisms of Sociobiology
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Sociobiological approaches to human behaviour widely criticized
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e.g., study of male sexual coercion as a potentially adapted trait was criticized as
justifying misogyny and sexual violence
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the term “Sociobiology” became used much less frequently, but a specific approach to
psychology emerged: Evolutionary Psychology
Evolutionary Psychology
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Evolutionary Psychology heralded itself as a ”new science”
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however, most of the theory and models had previously been developed in animal
behaviour / behavioural ecology
Evolutionary Psychology and the SSSM
Unit 3.3
What is Evolutionary Psychology?
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Comparison to the “Standard Social Science Model” (SSSM)
SSSM and cultural relativism
Assumptions of the SSSM:
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1. The Blank State (Empiricism)
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2. Irrelevance of Biology
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3. General Laws of Learning
Critique of the SSSM (Tooby and Cosmides)
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1. Misunderstands the Nature of Development
all environmental influences must act through genes
e.g. language development: humans vs. apes
species have predispositions to acquire certain kinds of information
2. SSSM sets a false dichotomy
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it is NEVER nature versus nurture
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experience/environmental influences modify expression of the genes through
developmental processes
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some developmental processes are more or less prone to environmental influences
3. Learning is not governed by general laws.
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Learning and cognition are modular.
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Different modules have been subject to differing natural selection in different species.
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The mind is like a swiss army knife, multiple tools for multiple problems
4. SSSM divides social and natural sciences.
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a curious effect, given that the goal of the behaviorists was to make psychology more
scientific
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Psychology –the study of the mind and behaviour.
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these are biological phenomenon
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psychology (and all social science) is part of the life sciences
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culture, mind, social behaviour etc. are biological phenomenon, not exempt from
biology
5. SSSM does not explain design
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SSSM explanations can describe phenomenon, but not explain why they are that way.
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Traits (including behaviour) are design products of natural selection and have a
FUNCTION.
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social science –constrained to proximate explanations (v. ultimate explanations)
Principles that Define Evolutionary Psychology
1.
brain is a physical system, a computer designed to generate contextually appropriate
behaviour
2. neural circuits were defined by natural selection to solve problems faced by our ancestors
3.
most of our cognition is hidden from our consciousness
4. different neural circuits are designed to solve different problems (modularity)
5.
our modern skulls house a stone-aged mind
Interview with Tooby and Cosmides
Unit 3.4
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https://youtu.be/nNW_B8EwgH4 : Interview with Tooby and Cosmides from ReasonTV
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Explicit exchange and social distance as our hunter gather past we can not digest these
differences
Criticisms of Evolutionary Psychology
Unit 3.5
Criticism of Evolutionary Psychology
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Panadaptationism
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Evolutionary Psychology (and Behavioural Ecology) have been criticized as thinking
everything is an adaptation
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”The Spandrels of San Marco” critique by Gould and Lewontin- spandarl function is just
design but acc needed for structure
Hyper-adaptationism
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Adaptationist Stance –philosopher D. Dennett
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hypothesize a trait is an adaptation
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formulate predictions
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test hypothesis- then its ok
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we need to be clear about whether we are
testing if a trait is an adaptation
assuming traits are adaptive to formulate another hypothesis
remember that not all traits are adaptations
Criticism of Evolutionary Psychology
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Evolutionary Psychology espouses genetic determinism (or biological determinism)
Simple-minded thinking
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much resistance to sociobiology or evolutionary psychology, and many silly ideas
within it, result from simple-minded thinking
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Deterministic Fallacy
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Naturalistic Fallacy
Deterministic fallacies
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Genetic fallacy is that genetic traits are inflexible (determined)
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Most traits ARE flexible and develop through gene-environment interaction.
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e.g., PKU -u can change although genetic, IQ, sociopathology
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Many who fear genetic determinism ignore cultural determinism.
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Both ideas are fallacies, and reflect the FALSE distinction between nature and nurture.
Fight the temptation!
Criticism of Evolutionary Psychology
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Evolutionary Psychology is reductionist
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distinguish between hierarchical reductionism versus ‘greedy’ reductionism
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reductionism is a key component of science
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however, we need to remember that systems have emergent properties
Criticism of Evolutionary Psychology
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Evolutionary Psychology is politically incorrect
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e.g., mate choice studies may perpetuate and promote gender stereotypes
Naturalistic fallacy
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What is natural is right/ good.
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A common critique of evolutionary analyses is that they justify social inequities, sexism
etc.
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However, natural selection is blind. Adaptations are orthogonal to morality
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parasites, diseases, selfishness are products of nature
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so are cooperation, love, and the human capacity to invent vaccines
Criticism of Evolutionary Psychology
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Evolutionary Psychology approaches are not inherently right wing
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However, simple and fallacious hereditarian claims about human behaviour ARE often
adopted by
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libertarians
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fascists
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white supremacists
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to further their political goals
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N.B. the political turn at the end of the Tooby & Cosmides interview video
Criticism of Evolutionary Psychology
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Evolutionary Approaches to Human Psychology often oversimplified for political
agendas
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by both right wing and left wing
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remember that evolution and biology are complex
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evolutionary explanations are unlikely to be simple
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evolutionary explanations are not superior explanations, they are a different type of
explanation
Different Approaches to Evolution and Human Behaviour
Unit 3.6
Principles that Define Evolutionary Psychology- REPEAT
(Santa Barbara School)
1.
brain is a physical system, a computer designed to generate contextually appropriate
behaviour
2.
neural circuits were defined by natural selection to solve problems faced by our
ancestors
3.
most of our cognition is hidden from our consciousness
4.
different neural circuits are designed to solve different problems (modularity)
5.
our modern skulls house a stone-aged mind
Modularity
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components of learning, memory, cognition have modular components
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e.g., semantic memory, working memory, procedural memory
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to what extent have they independently responded to natural selection?
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One of the tenets of Evolutionary Psychology is that the Mind is modular
consisting of functionally distinct units.
Rather than an all-purpose general machine, it is more like a swiss army knife
The Ancestral Environment
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Evolutionary Psychology posits we are adapted to ancestral conditions
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hunter gatherer from about 1,000,000 years ago to 8,000 years ago (or longer)
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assumptions/inferences drawn from current day hunter-gatherer peoples
human timeline in a year
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Jan 1: Divergence with Pan lineage
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Dec 31, 6:00 AM: domestication
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Dec 31, 3:00 PM: urbanization, cities
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Dec 31, 11:40 PM: Industrial Revolution
EEA
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“environment of evolutionary adaptedness”
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our species did not evolve in the current environment
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many currently nonadaptive behaviour may reflect ancestral selection
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we don’t know what the environment was exactly like, but we can make assumptions
The EEA
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high risk
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starvation, predation
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scarcity of some nutrients
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iodine, some vitamins
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small groups 50-100
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hunter-gatherer existence
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sex differences in hunting v gathering?
Population Density
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Hunter gatherer
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tribe of 60 or so per 400 sq. miles
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Major city
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6 million people in the same space
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change from knowing everyone to continuous interaction with strangers
Human Zoo
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book by Desmond Morris
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best comparison for human behaviour is not free-living animals
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animals in artificial environment
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The Human Zoo- look at animals in zoo bc cities
Other Approaches
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The Evolutionary Psychology approach promoted by Tooby/Cosmides is not the only
evolutionary approach to human psychology
Human Behavioural Ecology
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also called Human Evolutionary Ecology
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does not assume modularity, or adaptation to EEA
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use life history theory and evolutionary approaches to study traits and behaviours of
people in an ecological context
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focus on how behaviour varies across ecological contexts
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emphasizes use of models to make predictions
Human Behavioural Ecology
Monique Borgerhoff Mulder
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background in social anthropology
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applied economic and ecological models to study polygyny in rural African peoples
Evolutionary Anthropology
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studies humans’ place in nature, connections with primatology
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how did humans evolve from primate and hominid ancestors?
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connects with biological and physical anthropology, other social sciences
Evolutionary Anthropology
Sarah Blaffer Hrdy
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pioneer in understanding female behaviour
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studied infanticide in Langur monkeys
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extensive research on motherhood and maternal behaviour
Evolutionary Psychology
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Evolutionary approaches to Psychology and Human Behaviour come from a variety of
fields
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The names we give to academic disciplines is somewhat arbitrary
How researchers define themselves can vary with context and time
Development as a Central Process
Unit 3.7
Development
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the idea of nature versus nurture is a fallacy
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a false dichotomy
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development as an epigenetic process
Development
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nature versus nurture false dichotomy has various forms
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genes vs. environment
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biology vs. learning
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however, the only way to get from genotype to phenotype is via developmental
interaction with the environment
Nature and Nurture
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debate reflects false dichotomy
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analogies for this false division:
is a field’s area due more to its length or width? (Hebb) cant say whats more important
is a cake due more to the recipe or its ingredients (Bateson)
Development and “Instinct”
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historical debate between Daniel Lehrman and Konrad Lorenz
Concept of Instinct
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problem in defining instinct
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instinctive or innate behaviours usually:
appear early during development
stereotyped
complete
however, may be result of similar environment, not genetic influence (e.g. imprinting)
Innate behaviour may be modified by experience
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gull chicks peck at parent’s bill to elicit food regurgitation immediately after hatch
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however, behaviour modified during first week of life
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rotate heads to grasp parent’s bill
become more specific in which stimuli will elicit pecking
Learning is influenced by genetics
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variation in preparedness to learn
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e.g. language learning
e.g. taste aversion learning
rats learn to associate taste with illness and light with electric shock
birds learn to associate visual cue with illness
Instinct
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The term “instinct” now generally not used in science
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a descriptor that doesn’t really explain how a trait develops
Development
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is a process of gene-environment interactions (both)
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influence of environment may vary at different periods of development and among
traits
Epigenetic Model of Development
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development as a process in which each stage in the growth and differentiation of an
individual arises from the
… preceding stage through the joint action of genetic and environmental determinants
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at any point in ontogeny, current phenotype sets stage for further development guided
by genes whose expression are more or less modified by environmental influences
Waddington’s Epigenetic Landscape- development like ball rolling down hill
Heritability and inheritance
Unit 3.8
heritability
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Heritability is a population genetic measure applied to personality and individual
differences
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h2originally introduced as estimate of probability that an offspring would inherit a trait
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in selective breeding experiments, used to estimate proportion of total variance due to
genetic variance
inheritance
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it makes no sense to say that a trait is caused X% by genes and Y% by the environment
inheritance
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Example: UVb and melanin production
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melanin expression depends on UV exposure
thought to be trade-off between skin cancer protection and vitamin D synthesis
heredity effects: selection for optimal melanin pigmentation varies across the globe
environmental effects: phenotype is plastic and responds to recent UV exposure
phenotypic plasticity
a facultative trait
inheritance
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How can melanin levels be X% genes and Y% environment?
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consider the following two explanations:
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Separate twins at birth: differences due 100% to environment.
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Melanin depends on expression of melanin gene: differences due 100% to genes.
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Nature-Nurture distinctions should be rejected vigorously and often!!
Phenotypic plasticity
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a single genotype can give rise to multiple phenotypes
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developmental plasticity
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seasonal plasticity
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short term plasticity
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function between genotype and phenotype is termed a reaction norm
heritability
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heritability estimates are environment specific
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do NOT indicate a trait is X% genetic!!
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heritability means the proportion of variance accounted for by genetic variation
heritability estimates
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refer to populations, not to individuals
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cannot be generalized to populations from dissimilar environments
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Multiplier effect – genetically similar individuals seek out similar environments
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e.g., Turkheimer et al. (2003) – heritability of IQ was very low in impoverished twins and
very high in affluent twins
heritability
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even if differences within groups are explained by high heritability, that does not mean
that between-group differences are due to genetic factors
Heritability ex- enviro makes huge difference
Heritability within a group does not imply that group differences are due to genetic factors. Environmental factors
could completely explain group differences, even in a case where genetic factors completely explain within-group
differences. Lewontin's metaphor150 illustrates this point. As shown in the figure (reproduced, with permission,
from Ref. 147 © (1995) Elsevier), plants grown under uniformly normal conditions exhibit genetically determined
variation in height from plant to plant. The same species grown under uniformly deficient conditions also shows
completely genetic control of height. Yet the second group is shorter than the first — a group difference entirely
caused by the deficient environment, despite complete heritability. This example emphasizes that any account of
group differences in intelligence cannot use within-group heritability to explain between-group differences.
heritability
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Is h2 good for anything?
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artificial selection studies
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what would you predict would be the h2 for a trait under intense natural selection?
genetic variation reduced with strong selection
h2 will approach zero, despite important genetic influence