Berk Chapter 2

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Lecture 2

• Berk Chapter 2
• Theories of Development
• Methods of Study
• Correlations Experiments
• Research Strategies
• Cross-sectional Longitudinal
• How genes environment work together
• 4 models

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BASIC THEORIES OF CHILD DEVELOPMENT

• Why bother with theories?
• Facts are only facts
• a description of what we can observe
• Theories help us
• make sense of our observations.
• allow us to predict explain the changes

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Theories

• Theories help us make plausible stories that
  allow us to make sense of the facts
• help us understand and interpret facts
• explain make predictions in new scenarios
• Even good theories may be wrong
• But good ones act as stimulus for new questions

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Theories are useful

• We use implicit theories all the time
• life is easier in a predictable world
• Examples
• Girlfriend/boyfriend has found someone new
• Predict he/she will break next date
• If prediction correct, predict more avoidance
• If prediction wrong, maybe wanted to wash his
  hair, worried
• Observe that child is cross, cranky
• gt hunger? gt eat
• gt needs a nap? gt sleep

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The observation

• The father of a 2-yr old finds that he becomes
  very impatient with his daughter, when,
• night-after-night, she claims she cannot fall
  asleep because of a monster that comes out in
  the dark.
• Although each night the father tries to reassure
  and comfort his daughter, the next morning she
  does not remember his attempts to reason with her
  regarding her fear.
• He should probably

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4 theoretical perspectives

• A) try to understand the hidden causes and
  meaning of his daughters dreams
• B) give his daughter a reward the following
  morning if she stayed in bed until falling asleep
  the night before.
• C) realize that, because of her limited cognitive
  abilities at age 2, she cannot be rationally
  reasoned with.
• D) consider how he can structure his interactions
  with his daughter to mentor her through her
  fear.

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What was your answer?

• A)
• B)
• C)
• D)

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Basic Theories

• Psychodynamic
• Freud, Erikson
• Behavioural
• Skinner
• Social-cultural
• Vygotsky

• Cognitive
• Piaget
• Social Learning
• Bandura

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Psychodynamic Theories

• Focus
• Freud on psychosexual instincts pleasure
  principle
• Erickson on psychosocial challenges.
• Both Freud Erikson focus on
• our unconscious motivations
• are specific tasks challenges at each stage.
• overcoming early challenges makes later ones
  easier to handle
• early success lays foundation for later success.

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Psychodynamic normative stages

• Ages Freud Erikson
• 0 - 1 oral trust vs mistrust
• 1 - 3 anal autonomy vs shame/doubt
• 3 6 phallic initiative vs guilt
• 6 11 latency industry vs inferiority

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Psychodynamic ChallengesA War Analogy for
Development

• Development akin to an invading army
• Eg Napoleons army heading into central Russia
• Each battle along way developmental crisis
• need psychic energy/ troops to attend to each
  crisis
• If crisis successful, then energy/ troops free
  for next battle
• If unsuccessful, then army must leave energy/
  troops behind to battle insurgents,
• have fewer resources for the next battle

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Limitations

• Psychodynamic
• Vague stages, difficult to test empirically
• psychosexual stages controversial at best
• Dark view of human nature derived from work with
  patients with psychological problems

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Strengths

• Psychodynamic
• Theory of motivation, emotion, personality
• Notion of the unconscious influence
• Presents a dark view human nature
• an important component
• Emphasized individuals unique life history as
  worthy of study.

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Example of strength of psychodynamic theory

• How children internalize parental beliefs
• In initiative stage, preschoolers start to model
  selves after same-sex parent
• and internalize values beliefs of parents
• In autonomy stage
• they learn self-control, choosing for themselves

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Cognitive Theory Piaget

• How do children come to think understand the
  world like adults?
• Theory focuses on
• how children actively explore the world
• emphasize qualitative changes in thinking

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Piagets Stages

• Age
• 0 2
• 2 7
• 7 11
• 11

• Stages Description
• Sensorimotor senses
• Pre-operational symbols
• Concrete operations reasoning
• Formal operational abstract logic

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Examples of Piagetian stages

• Way to observe change in thinking over childhood.
  
• In sensorimotor, babies explore world with senses
  
• Learn by mouthing, stroking, looking
• Exploration centres on their own bodies.
• In pre-operational, kids explore in new ways
• when they learn to crawl and walk
• Use symbols like language, pretend play,
• Exploration is centred outside of self, on larger
  world
• In operational, kids are able to understand
  constancy of numbers, volume, size, shape

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Limitations

• Piaget
• Limited empirical support for the specific ages
  at which cognitive changes occur
• Underestimated childs cognitive capabilities
• Rate of cognitive development can differ in
  different domains
• Eg, understand constancy of number but not volume
  (horizontal décalage)

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Strengths

• Piaget
• Historical started the field of cognitive
  developmental psychology
• Many of the questions he raised are still being
  examined today
• Idea that children are active thinkers
  contribute to their own experiences

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Behaviour Theory

• Skinner
• focus on observable behaviour
• principles of conditioning learning
• Reward
• Punishment

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Behaviourism

• Principles of operant conditioning
• positive reinforcement (action gt outcome)
• eg
• negative reinforcement (action gtless neg outcome)
• eg
• eg
• punishment (action gt negative outcome)
• eg

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Limitations

• Behaviourism
• Narrow view of environmental influences
• Ignores role of mental world
• Thoughts, feelings, attitudes, motivations

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Strengths

• Behaviourism
• Powerful means to change behaviour
• eg reduce fears, train pets, change
  characteristics
• Discipline of children
• Principles apply across childhood adulthood.

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Banduras Social Learning Theory

• theory of social development
• Children model, imitate others behaviours.
• Most likely occurs when child is uncertain
• when model is admirable, powerful, nurturing
• Eg of bad modeling Bobo doll
• Eg of good modeling empathy, respect, sharing
• Through modeling
• children learn about social situations
• develop self-regulation
• and sense of control over social situations

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Limitations

• Social Learning
• Focuses only on social development
• Narrow view of environmental influences
• ignores childrens social conditions
• Ignores childs physical and cognitive abilities

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Strengths

• Social Learning
• understanding how social processes influence
  development
• Identified an important mechanism of
  developmental change
• Eg in helping children incorporate values
• Hard work, responsibilities, ways to communicate
• and appropriate social behaviour with peers
  sibs
• Sharing, cooperating, playing

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Vygotskys social-cultural theory

• Focuses on social origins of mental functioning
• Language is learned as a social and cultural
  process as way to interact and communicate with
  others.
• Adults help children by guiding them
• offering support in the form of scaffolding.
• Eg adult helps child with puzzle
• Guidance on how to do it, trying shapes, colours
• or Mom offers child a new word
• as child tries to express him or herself.

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• Snoopy gets scaffolding

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Limitations

• Vygotsky
• Less emphasis on biological, heredity in
  development
• Less emphasis on childs own capacity to shape
  development

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Strengths

• Vygotskys
• Understanding transfer of culture, social
  knowledge from one generation to next
• Understanding social aspects of cognition
• Motivations, attitudes

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Summary What good are theories?

• 2 important functions of theories
• 1. Organize and integrate information facts
  into a coherent story.
• 2. Lead to testable hypotheses or predictions
  based on our observations.
• No one theory purports to explain all aspects of
  development.

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Question

• Nine-yr-old David is more aggressive in the
  classroom than Maria. His teacher should
  probably
• A) give him stars and privileges when he behaves
  appropriately.
• B) refer David to a therapist who can get him to
  talk about his repressed urges.
• C) realize that Davids past social interactions
  have not challenged him to develop certain social
  competencies.
• D) have his vision, hearing, other perceptual
  abilities tested to find out why he is not able
  to concentrate on the class material.

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METHODS

• How do we study child development?
• Theories provide insights, hunches, ideas about
  development
• But do children behave and develop in the ways
  that theories suggest they will?
• How do we know?
• Next step is to find out whether the theories
  observations are correct
• or not

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Choosing a Research Strategy

• Research Methods
• The specific activities of participants
• Questionnaires
• Interviews
• Observations
• Etc.

• Research Design
• Overall plan for the study
• Permits the best test of a research question.

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Asking Research Questions

• When we want to know if a relation exists, we ask
  a research question.
• These questions are used to establish
  relationships and sometimes causes.
• Examples
• Is TV violence associated with higher aggression?
• Are infant motor milestones associated with
  season of birth?
• Do the prenatal Mozart tapes have any positive
  effect on intelligence later on?

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Strategies Designs

• I will discuss 2 main research strategies and 2
  principal designs used to investigate children's
  development.

• Research strategies
• Correlations
• Experiments

• Research designs
• Cross-sectional
• Longitudinal

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Correlations

• You need two variables
• eg, hours of TV viewing / measure of aggression
• eg, infant motor milestones / season of birth
• Researcher does not systematically change
  anything
• about environment or experiences of participants.

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Definition of Correlation

• is an index or estimate of how much two measures
  vary together
• correlation coefficient r

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Correlation Coefficients

• Magnitude (Size)
• Size of the number between 0 and 1
• Closer to one (either positive or negative) is a
  stronger relationship

• Direction
• Indicated by or - sign
• Positive () as one variable increases, so does
  the other
• Negative (-) as one variable increase, the other
  decreases

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Examples of Correlation Coefficients
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Correlations
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TV aggression in preschoolers

• Example classic study by Singer Singer (1981)
• Are differences in TV viewing aggression?
• Parents interviewed about amount of TV kind of
  programs preschoolers watched
• Amount of aggressive TV watched
• the independent variable
• Observers rated aggression in nursery school
• Aggression observed in children
• the dependent or outcome variable

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Results

• Children spent average of 23 hours/wk watching TV
• TV viewing clearly related to aggression
• more action adventure shows watched
• more aggressive preschoolers were with peers

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In the TV-aggression example

• what kind of correlation do we have?
• between what variables?

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Other examples of correlations

• Reading to child and vocabulary size,
• more reading larger vocabulary
• ? correlation
• Age cognitive development
• ? correlation
• Good parenting child behaviour problems
• ? correlation

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Cautions About Correlations

• Relation between 2 variables does NOT mean one
  caused the other
• They are only related in some systematic way
• In the TV-aggression Singer study,
• we can't say watching violent TV caused
  aggression
• could be that children who are already aggressive
  prefer to watch violent types of programs
• Correlations cannot establish cause!

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Experimental Strategy

• Experiments - only method that can establish
  cause.
• Systematically change characteristic of child's
  environment or childs experience
• Independent variable - IV
• The variable changed or manipulated
• expected to cause changes in another var
• Dependent variable DV
• variable measured for evidence of change

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Experiments

• Use at least 2 groups
• experimental (treatment) control
• Individuals are randomly assigned to a group
• want both groups are same at start
• want experimental and control groups to be as
  similar as possible, differing only on the
  treatment given.

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Experiments

• Experimental group - receives treatment
• 1 group plays aggressive videos
• Control group receives no treatment
• 1 group plays non-aggressive videos
• When changes in IV (type of video) result in
  changes in the DV (aggression), you can infer
  that one causes the other.

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3 Types of Experimental Studies

• lab - children randomly assigned to treatments
• In lab, children view violent show or sports show
• field - introduce change in natural setting
• Eg experiment in nursery school TV viewing
• 3wk baseline, 4wk 1/2 class violent 1/2
  prosocial, 2wk behaviour assessment
• natural - capitalize on change occurs naturally
• Eg effects of hospitalization, adoption, disaster

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Research Methods

• Two major goals
• Eliminate alternative explanations
• E.g., pre-existing group differences
• Reduce bias
• Children are representative of all children
• Task materials used represent what you are
  trying to study in the real world

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2 Key Study Designs

• Cross-sectional
• People of differing ages all studied at the same
  time
• Longitudinal
• Same participants studied repeatedly at different
  ages

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Cross-Sectional Designs

• Compares different groups of children of
  different ages at the same time
• Example
• compare groups children ages 4, 8, 12, 16
• might find that amount of hitting and physical
  aggression greater in younger kids
• but verbal insults greater in older kids
• 2 outcome (DV) variables at 4 ages (IV)

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Advantages of Cross-Sectional

• Data collected over a short period of time
• Can study a range of ages to identify age
  differences.

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Disadvantages Cross-sectional

• Does not tell about age changes
• what individual children were like when they were
  younger and how they developed
• Only age differences
• Does not control historical cohort variables
• depressions, war, parent rearing styles change,
  etc
• Tells nothing about the stability of variable
• will aggressive 4 yr old become aggressive 10 yr
  old

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Longitudinal Research Design

• Compares the same children over time.
• Examples
• Effect of prematurity on later IQ
• Effect of preschool aggression on adolescent
  delinquent behaviour
• Gold standard in developmental research

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Longitudinal Study of TV Violence

• Example by Huesmann, 2003
• Follow-up study of 329 children
• original study in 1970s 1980s when kids were
  6-10 yr
• shows relation between amount of TV violence
• Starsky/Hutch, 6million man, woman, Road Runner
• and adult aggressive behaviour 15yrs later
• Self others reports of aggression
• verbal physical, aggression, aggressive
  personality, aggression toward spouse
• archive govt reports speeding criminal
  convictions

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Longitudinal TV-Aggression Study (Huesmann et al,
2003)

• Results
• Childhood exposure to violent TV predicted young
  adult aggression in males females
• Identification with TV characters a perception
  that the TV violence was realistic predicted
  later aggression
• After controlling SES, intelligence, parenting
  behaviours style

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Longitudinal TV-Aggression Study (Huesmann et al,
2003)
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Longitudinal TV-Aggression Study (Huesmann et al,
2003)

• Conclusions
• Steady diet of violent TV does predict later
  aggressive behaviour in those from
• all social strata
• all levels of initial aggressiveness (defined by
  classmates)
• The worst are Dirty Harry shows where
• child identifies with perpetrator
• show pretends to be real life
• perpetrator is rewarded for violence

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Longitudinal Design

• Advantages can
• observe same kids at different points in their
  development
• evaluate actual changes in behaviour, not just
  age differences
• determine the impact of earlier events on later
  behaviour
• assess the stability of a behaviour across age

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Longitudinal Design

• Disadvantages
• Long time to conduct study
• importance of research may change, obsolete
• Expensive
• Selective attrition
• Lose participants through illness, moves

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Longitudinal Design

• Disadvantages
• Practice effects A change in outcome (e.g., IQ)
• may be due to repeated testing
• not a true developmental change
• Cohort effects Results may be unique to 1 cohort
  
• Eg children born in 1920's - Great Depression,
  WWII
• May have unique effect on development
• experiences of 4-year-old today 50 years ago
• significantly different?

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Conclusion

• Understanding basics of methods strategies is
  important
• like understanding the bricks mortar that make
  up buildings
• gives you tools to start understanding the
  science of child development
• can go to source articles
• understand what they are talking about
• and why they do what they do

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Influences of nature nurture

• What is the relationship between genes
  environment?
• Discuss various ways heredity and environment may
  combine to influence complex traits.

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A tennis story

• We see a 5-yr-old boy on tennis court
• An adult joins him on the court.
• Child says, want to play?
• Adult gently hits the ball
• Ball rockets back at him
• Things escalate
• Adult finally triumphantly scores a point
• Parents drive up to pick up son

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• Parents are Steffi Graaf Andre Agassi
• Two world champion tennis players
• Moral of the story
• Early tennis lessons necessary
• But genes help a lot too!

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How do genes environment work together?

• 4 Theoretical Models
• Canalization (Waddington, 1957, 1966).
• Reaction range (Gottesman, 1963)
• Genetic-environmental correlation (Plomin, 1994)
• Epigensis (Gottlieb, 1998, 2000)

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Canalization

• Waddington (1936) model of how development
  occurs
• Child is like a ball rolling along possible
  developmental paths.
• Early on, development is less susceptible to
  environmental forces.
• Eg Most infants will acquire motor milestones.
• Later, environment is more influential
• Eg tennis, music lessons necessary for skills

Environment
Age
Epigenetic Landscape
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Canalization

• Potential Plasticity
• Early on, you have maximum potential,
• a full range of developmental pathways.
• Later on, choices and experiences restrict
  possible pathways.

Environment
Age
Epigenetic Landscape
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Canalization

• Stability of development
• as a buffered pathway
• eg illness or malnutrition
• Catch-up growth
• No books in home
• child still learns to read
• No hearing in 1st year
• Can be normal by 3yr

Environment
Age
Epigenetic Landscape
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Canalization

• Theory which focuses on our possible
  developmental pathways
• Highlights how, with any given set of genes, our
  environment can put us on different pathways.

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Reaction Range

• Heredity provides range of possible development
  outcomes
• Environment determines where in the range you
  develop to
• Genes relate to a childs responses to different
  environments
• eg IQ is heritable but environment matters

Normal IQ
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Reaction Range

• Different genetic ranges lead to different
  responses to the environment.
• All poorer IQs in bad environ.
• All better IQs in best environ.
• Different responses in moderate environs
• Ben responds steadily
• Linda responds quickly
• Ron requires moderate environ to start responding
  
• IQ is relative to peer group

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Reaction Range

• Focuses on how much we achieve in a given domain
  of behaviour
• Genes give us the range of abilities
• environment influences where on that range we
  land.

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Genotype-Environment Correlations

• 3rd Model of how genes interact with our
  environment
• Comes from field of behavioural genetics
• Plomin, 1977, 1994
• Interested in influence of genes on our
  environment
• Propose 3 ways genes influence the environment
• Passive start early and peter off
• Evocative constant over life
• Active genes influence you to put yourself in
  particular environment

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Genotype-Environment Correlation

• Passive
• Passive link between childs genes environment
• Parents have similar genes so produce
  environments that are compatible / correlated
  with the childs genetic predispositions
• eg athletic parents produce child with
• Athletic genes encourage athletic environments
• Passive because childs own genes are not
  influencing the environment

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Genotype and Environment

• Evocative
• ie genes of child evoke responses
• a. Genes influence infant/child behaviour, which
• b. influences how others respond to the child.
• c. Thus, the genes influence the environment
• eg Friendly baby gets evokes more positive social
  stimulation than a quiet baby
• eg cranky child evokes more cranky social
  interactions with others than calm child

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Evocative correlation?
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Genotype and Environment

• Active Niche picking
• Children actively seek or create environments
  that are compatible with their genetically
  influenced interests or abilities
• In pursuing your genetic interests, you expose
  yourself to an environment compatible or
  consistent with your genetic interests.

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Active - Niche Picking

• eg genetically bright children hang out with
  intellectually stimulating peers, adults,
  activities
• Child with genetic musical talent seeks a
  musically stimulating environment.

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Age Changes in G-E Effects
eg niche picking
more influence
similar influence over time
eg, personality
eg, parents
less influence

• Relative importance of each G-E correlation
  (Shaffer, 2002)

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Genetic-environmental correlation

• Focuses on ways in which genes influence the
  environments we grow up in.

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Epigenesis

• Bidirectional influences focused at biological
  level
• Genes effect environment,
• and environment effects gene expression too!
• Eg, babys healthy diet gt brain growth gt new cell
  connections gt changes gene expression gt new
  behaviours (exploration) gt brain growth gt gene
  expression.

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Gene-Environment Models

• 4 Models summarized
• Canalization the developmental paths we end up
  on
• Reaction Range how much we achieve in a given
  domain of behaviour
• Genetic-environmental correlation ways in which
  genes influence the environments we grow up in
• Epigenesis environment influences gene
  expression (bidirectional)

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Conclusion

• Your first two lectures form the basis of
  understanding of CD
• Issues and foundations - important
• We will be using these concepts as we talk about
  developmental changes findings presented
  throughout the course
• Read Chapter 3 for next week