I' TRADITIONAL AND EVOLUTIONARY PSYCHOLOGY

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I. TRADITIONAL AND EVOLUTIONARY PSYCHOLOGY
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TP and EP

• How does Evolutionary Psychology differ from
  traditional psychology?
• What is Evolutionary Psychology all about?
• Levels of explanation in EP vs. traditional
  psychology

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TP and EP

• How does Evolutionary Psychology differ from
  traditional psychology?

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The role of metatheory in science

• Metatheory a set of backgroud assumptions
  accepted by all or most scientists working on a
  particular field
• laws of Newton in physics
• laws of evolution in biology
• Metatheory provides guidelines for constructing
  and testing new theories and hypotheses
• Theories on field of study must be consistent
  with the metatheory
• all specific theories must be in accordance with
  the metatheory

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The role of metatheory in science

• The background assumptions provided by the
  metatheory are seldom questioned, especially if
  they manage to explain anomalous findings
• Sometimes researchers are not even aware that
  they possess certain background assumptions or
  that these assumptions affect their work

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Current metatheory in psychology

• The Standard Social Science Model (SSSM)
• The Blank Slate (tabula rasa)
• Purest form
• Infants everywhere are born the same and have the
  same developmental potential
• Infants have virgin minds with no natural,
  innate, inborn tendencies or inclinations
• Any inclinations adults express result from
  unique life experiences

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Blank Slate...

• Adults differ profoundly in their behavioral and
  mental organization
• Humans everywhere show striking within group
  similarities and between group differences
• ? Any differences between people arise from
  differences in experience (culture, social
  environment), not from differences in underlying
  biology
• ? The cultural and social environment shapes
  our psychological mechanisms, makes us who
  we are

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Roots of the Blank Slate

• The idea of a Blank Slate is centuries old
  (enlightenment philosophy)
• Usually attributed to John Locke's (1632-1704)
  political philosophy foundation for liberal
  democracy, equality despite one's status at birth
  ? weapon against church, monarchs and slavery
• The Blank Slate was particularly appealing during
  past century
• Slavery Immigration
• Women's rights
• Child development, education and upbringing
• World Wars and the Holocaust
• Behaviorism
• Social equality

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Problems with SSSM

• THE BLANK SLATE
• A blank virgin mind is a general purpose computer
  that can respond to any type of input and thus
  learn from experience
• How can something truly blank respond to
  anything? Virgin minds have no rules for
  responding
• If a system has no rules for responding, there is
  no systematic response, and thus, no learning
• ? General purpose learning mechanism has no
  specific rules for responding to specific input,
  thus it cannot account for learning
• ? Moreover, recurring patterns of response seem
  to be part of species' nature, i. e. babies react
  to similar stimulus in similar ways

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Current metatheory in psychology

• The Standard Social Science Model (SSSM)
• 2. General-purpose learning mechanisms
• If everything is learned by experience, the brain
  has to be capable of learning to begin with
• We are born with General purpose learning
  mechanism GPLM can handle many different kinds
  of input and produce many different kinds of
  output
• There is only one or few general learning
  mechanisms that account for diverse effects of
  experience
• ? Mind is a general-purpose computer

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Problems with SSSM

• 2. EP GENERAL PURPOSE LEARNING MECHANISMS CANNOT
  EXPLAIN ENVIRONMENTAL EFFECTS
• Definition of learning a set of processes that
  allow experience to modify behavior
• Real world consists of many different and
  specific types of problems
• Specific problems require specific programs or
  processes that can deal with specific type of
  input and produce specific type of output
• General purpose learning mechanisms cannot deal
  with various specific types of input, and thus
  cannot solve specific problems
• ? There are no general-purpose problems, thus
  there is no general purpose learning mechanism

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Problems with SSSM

• Example Language learning
• Auditory exposure to language triggers specific
  programs in infants that allow them to develop
  mastery of language
• Innate response patterns to language are an
  integral part of human nature, missing in other
  species
• Isolation or other linguistic deprivation
  prevents the learning process ? feral children
• Specific type of input triggers specific innate
  response patterns that allow learning to take
  place
• EP Numerous specific learning mechanisms, no
  general purpose computer

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Current metatheory in psychology

• The Standard Social Science Model (SSSM)
• 3. Irrelevance of Biology
• Biological constraints on human behavior are
  minor and unimportant
• We have only few basic biological drives (hunger,
  thirst, sex and sleep)
• Biology sets broad boundaries for development,
  which is guided by experience
• ? Experience plays the leading role, biology is
  a side kick

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Problems with SSSM

• 3. NATURE AND NURTURE -DICHOTOMY
• Nature vs. nurture, biology vs. innateness, genes
  vs. environment
• Are we mainly shaped by what happens to us during
  our lifetime (learning from experience)?
• Or was there something innate shaping us before
  we were even born?
• How much genes contribute to traits and how much
  the environment?
• Are we the product of nature or nurture?

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Genetic fallacy

• 3. NATURE AND NURTURE DICHOTOMY
• is based on the misunderstanding that
• evolved (genetically determined) traits are fixed
  and inflexible
• learned traits are unfixed and flexible
• Genetically based traits are often highly
  responsive to the environmental conditions
• Invalidates the gene-environment, nature and
  nurture dichotomy!
• Are we the product of nature or nurture? is a
  question missing its point

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Genotype and phenotype

• Genotype ? All the genes you carry, never
  changing, unobservable (cannot be seen by
  external observer)
• Phenotype ? All the characteristics and traits
  you possess, as perceived by external observer
• physical e.g., eye and hair color, height,
  weight, etc.
• psychological personality, reaction styles,
  behavior
• How genotype affects phenotype?

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Obligate and facultative traits

• Evolution shaped genes for both obligate and
  facultative traits
• Obligate trait is a characteristic that does not
  change in response to environment
• Gene is always expressed in predetermined way
  (e.g. blood type)
• Facultative trait is a physical characteristic or
  behavioral trait that is highly responsive to the
  environment
• Gene's expression depends on environmental
  factors (e.g. UV exposure ? melanin production,
  synthesis of vitamin D)
• Genes that respond to changing environment by
  adjusting the phenotype are more
  fitness-enhancing than less responsive genes ?
  selected for during evolution

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Obligate and facultative traits

• If the ability to adjust to environmental changes
  is so useful and fitness-enhancing, why are not
  all traits facultative?
• Whether selection favors obligate or facultative
  traits depends on the pattern of environmental
  variation
• Sometimes obligate adaptations that resist
  environmental interference offer the best
  solution in a wide range of environments
• Selection tends to favor facultative traits when
• Environmental conditions vary within the lifetime
  of the individual (organism must survive in
  different environments, e.g. varying UV levels
  during winter/summer)
• The fittest alternative varies from one
  environment to next (e.g. level of melanin
  production depends on the season)
• Most behavioral traits evolved as facultative,
  because they could offer rapid flexibility in
  changing environments

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Problems with SSSM

• 3. Nature and Nurture -dichotomy
• Causes of behavior cannot be divided between
  nature and nurture
• Biological and environmental facts are not
  mutually exclusive explanations
• Nature and nurture work together in the
  development of traits
• Interaction between genes and environment cannot
  and should not be distinguished
• RIGHT QUESTION
• Why genes and environment interact in a
  particular way?
• Why does the environment have some particular
  effect?

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Problems with SSSM

• 4. SSSM CREATES A GORGE BETWEEN NATURAL AND
  SOCIAL SCIENCES
• SSSM divorces psychology from natural sciences,
  especially biology, even though biology makes
  possible everything we are and do
• Behavior is studied in isolation in psychology
  and in biology, although living things as
  biological objects conform to the rules of
  evolution and natural selection
• ? the behavior of all living things must be
  explained by terms of evolution
• Why is evolution so central in explaining the
  behavior of animals, but not in explaining human
  behavior?

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Problems with SSSM

• 4. SSSM CREATES A GORGE BETWEEN NATURAL AND
  SOCIAL SCIENCES
• All science should be a linked, single, coherent
  endeavor
• There is no scientifically defensible reason to
  divide between natural and social sciences
• Disregarding biological explanations may easily
  result in weaknesses in psychological
  explanations
• Psychological explanations cannot be in
  contradiction with biological explanations

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• What is Evolutionary Psychology all about?

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Evolutionary psychology An emerging metatheory?

• SIMPLE IDEA Explaining human psychology and
  behavior as a result of natural selection, i. e.,
  an evolved adaptation
• Logical and appealing to common sense only few
  deny the role of evolution in the designs of
  species
• Still, evolutionary psychology is a widely
  debated and critisized field of science and
  considered highly controversial
• What's the fuss about?

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Reasons for the controversy

• Main reasons for debate
• What is evolutionary psychology?
• Are the main background assumptions of EP
  acceptable?
• Are evolutionary hypotheses empirically testable
  and can we rely on the results?

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Evolutionary Psychology vs. evolutionary
psychology

• 1) What is evolutionary psychology?
• Evolutionary Psychology
• Scientific paradigm
• specific set of theoretical and methodological
  commitments, basic background assumptions, that
  guide theory formation and empirical research
• evolutionary psychology
• Field of inquiry
• the evolutionary study of mind and behavior
• any evolutionary perspective on human behavior
  and psychology
• significant differences in fundamental
  theoretical and methodological commitments
• that do not comply to commitments of EP (e.g.
  human behavioral ecology)

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Evolutionary Psychology

• This course is about Evolutionary Psychology!
• Evolutionary Psychology is a multidiciplinary
  research program that studies the psychological
  mechanisms underlying behavior as adaptations to
  the evolutionary environment of human species
• Evolutionary biology, especially evolutionary
  theory and laws of natural selection, form the
  core of Evolutionary Psychology
• Human behavior and psychological mechanisms
  underlying behavior cannot be understood without
  taking into account the environment in which
  these mechanisms evolved in the first place

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Evolutionary Psychology

• The central research problem
• How psychological mechanisms that underlie
  behavior have evolved under natural selection and
  how selection has shaped these mechanisms
• Evolutionary Psychology aims to explain the
  adaptive evolution of the proximate mechanisms
  that control behavior, not provide an adaptive
  explanation for behavior
• The aims
• To identify and specify adaptive problems in EEA
• To specify the proximate psychological mechanisms
  that have evolved to solve those adpative
  problems
• To empirically test the whether such mechanisms
  exist and how the systems function
• ?To create a unifying, overarching theory of the
  design of human psychology

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• Levels of explanation in EP vs. traditional
  psychology

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Levels of explanation

• Phenomenon can be explained on many levels
• Traditional psychology is concerned with
  mechanism
• What does the system do?
• How does the system work?
• ? Proximate explanations are searched in SSSM
• Evolutionary Psychology is also concerned with
  function
• Why does the system exist?
• Why does the system have the form it does?
• ? Ultimate explanations for proximate mechanisms
  are searched in EP

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Traditional vs. Evolutionary Psychology

• LEVELS OF EXPLANATION (Tinbergen)
• Proximate explanations
• Developmental genes, gene-enviroment
  interaction, age, sex-related variation
• Physiological neuronal, hormonal, biochemical,
  and biomechanical mechanisms
• Ultimate explanations
• Historical evolutionary origins, precursors
• Selective adaptive value of the trait

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Traditional vs. Evolutionary Psychology

• BUT these explanations do not compete with each
  other!
• IF one is right, the other is not necessarily
  wrong!
• Explanations compliment each other, providing
  different kind of information about the same
  phenomena
• EP aims at providing ultimate explanations for
  why certain proximate mechanisms are operative

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Evolutionary Psychology

• An attempt to unified psychology
• Dissolving traditional disciplinany boundaries
• An integrated understanding of Homo Sapiens
• Evolutionary cognitive psychology
• the cognitive system is a complex collection of
  inter-retaled information-processing devices,
  each evolved to serve a specific purpose (no
  GPLM)
• what problem the device was designed to solve,
  and why

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Evolutionary Psychology

• Evolutionary social psychology
• Many adaptive problems are social by nature
• mind must be populated with mechanisms dedicated
  to social solutions
• Evolutionary developmental psychology
• Temporal perspective different adaptive problems
  faced at various points in life
• cue of an adaptive problem activates a new
  adaptive mechanism

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Evolutionary Psychology

• Evolutionary personality psychology
• Origins and effects of individual differences
• individual differences adaptively patterned
• Evolutionary clinical psychology
• When evolved mechanisms dysfunction
• treating symptoms vs. causes, when to intervene
• Evolutionary cultural psychology
• Within-group similarities and between-group
  differences
• ideas, practices, rituals, beliefs, etc.
  explained by universal mechanisms that are
  differentially activated