Transcript History, Theory, and Research Strategies

History, Theory, and Research
Strategies
Chapter 1
What is Developmental Science?
 Developmental science – field of study devoted to
understanding constancy and change throughout the lifespan
 Great diversity exists among investigators who study
development, but all have 1 major goal…
 Major goal: to identify those factors that influence consistencies
and transformations in people from conception to death
The Field of
Human Development
 Scientific – conduct empirical research
 Applied – meaning practical use
 Interdisciplinary – meaning that people from many different
fields contribute to the study of human development
Theories of Development
 Theory – orderly, integrated set of statements that
describes, explains, and predicts behavior
 Example: theory of infant-caregiver attachment would:
 1) describe the behaviors of babies 6-8 months old as they seek the
affection and comfort of a familiar adult
 2) explain how and why infants develop this strong desire to bond with a
caregiver
 3) predict the consequences of this emotional bond for future
relationships
 Theories are important for 2 reasons:
 Provide organizing frameworks for our observations
 Theories verified by research provide a sound basis for how to
improve welfare of individuals
3 Basic Issues in Development
1.
2.
3.
Continuous or discontinuous?
One course of development or many?
Nature or nurture?
Continuous or Discontinuous?
 Continuous – a process of gradually augmenting the same
types of skills that were there to begin with
 Discontinuous – a process in which new ways of
understanding and responding to the world emerge a specific
times
 Stages – qualitative changes in thinking, feeling, and behaving
that characterize specific periods of development
Is there one course of development or
many?
 Stage theorists assume that people everywhere follow the same
sequence of development
 But… field of human development is becoming increasingly aware
that different contexts matter
 Contexts – unique combinations of personal and environmental
circumstances that can result in different paths of change
 Example:
 Personal: a shy person who fears social encounters develops in very different
contexts from people who are more outgoing and readily seek out other
people
 Environmental: people who grow up in a third world village society have
different experiences in their families than people who grow up in an
American city
Relative Influence of Nature and
Nurture
 Are genetic or environmental factors more important?
 Nature – inborn biological givens
 The information we inherit from our parents at the moment of
conception
 Nurture – the complex forces of the physical and social
world that influence our biological makeup and psychological
experiences before and after birth
 Example: do children learn language rapidly because they are
genetically predisposed to do so or because their parents
teach them from an early age?
Relative Influence of Nature and
Nurture (cont.)
 A theory’s position on the roles of nature vs. nurture affect
how it explains individual differences
 Nature/heredity
 Stability – that individuals who are high or low in a
characteristic (i.e., verbal ability or anxiety) will stay that way
throughout their life
 Nurture/environment
 Plasticity – that change is possible and even likely if new
experiences support it
Development as a Dynamic System
 More and more, researchers are regarding development as a
dynamic system
 Perpetually ongoing process
 Conception to Death
 Influences on development
 Biological
 Psychological
 Social
The Lifespan Perspective
 Leading dynamic systems approach
 4 major assumptions: development is…
 Lifelong
 Multidimensional and multidirectional
 Highly plastic
 Affected my multiple, interacting forces
 Within each age period change occurs in 3 broad domains
 Physical
 Cognitive
 Emotional/social
Lifespan View of Development
Periods of Development
Prenatal
Conception to birth
Infancy and Toddlerhood Birth to 2 years
Early Childhood
2 to 6 years
Middle Childhood
6 to 11 years
Adolescence
11 to 18 years
Early Adulthood
18 to 40 years
Middle Adulthood
40 to 65 years
Late Adulthood
65 years to death
Lifespan Assumption 1
 Development is Lifelong
 Every age period can have equally powerful effects on future
change
 No single period has a “supreme” impact on the life course
Lifespan Assumption 2
 Development is Multidimensional and multidirectional
 Multidimensional: development is affected by a blend of
biological, psychological, and social forces
 Multidirectional in 2 ways
 development is not limited to improved performance. Every period consists
of growth and decline
 Change is also multidirectional within each domain of development
(physical, cognitive, and emotional/social)
Lifespan Assumption 3
 Development is Plastic or Flexible
 Adaptations and changes can occur at all ages
 Aging is not an eventual “shipwreck”
 Different opportunities can yield different outcomes
Lifespan Assumption 4
 Development is influenced by multiple, interacting forces
 Biological, historical, social, and cultural
 These multiple influences work together
 Combine in unique ways in each individual life course
3 Types of Influences
 Age-graded influences – events that are strongly related to age and
therefore are fairly predictable in when they occur and how long they
last
 Example: most people begin walking shortly after their 1st birthday
 History-graded influences – influences on development unique to a
particular historical era (ex. epidemics, wars, periods of economic
prosperity or depression)
 Example: my great-grandmother was raised during a time of great economic
depression and because of this she stockpiled goods in her home. Today she
would be described in modern terms as a “hoarder”
 Nonnormative influences – irregular events that only happen to one
person or a few people and do not follow a predictable timetable
 Example: an inspiring childhood teacher or meeting your life-partner on a
random blind-date
Scientific Beginnings
 Scientific study of human development dates back to the late
19th and early 20th centuries
 Charles Darwin – 19th century theory of evolution
 Studying natural selection and survival of the fittest lead other
scientists to speculate about the evolution and development of
humans
 Thus, the scientific study of human development was born…
no pun intended
The Normative Period
 G. Stanley Hall – early 20th century - founder of the child
study movement
 Intensive efforts to describe all aspects of development
launched the normative approach
 Normative approach – measures of behavior are taken on
large numbers of individuals, and age-related averages are
computed to represent typical development
Mid-20th Century Theories
 Mid-20th Century – study of human development expanded
into a legitimate discipline and several theories and
perspectives emerged
 The psychoanalytic perspective
 Behaviorism and social learning theory
 Piaget’s cognitive-developmental theory
The Psychoanalytic Perspective
 1930s and 1940s driven by attempts to treat psychological
problems: How and why do people become the way they are?
 Psychoanalytic perspective answer: people move through a
series of stages in which they confront conflicts between
biological drives and social expectations.
 How these conflicts are resolved determines the person’s ability
to learn, to get along with others, and to cope with anxiety
 2 main theorists
 Sigmund Freud – psychosexual theory
 Erik Erikson – psychosocial theory
Psychoanalytic Perspective: Freud
 Psychosexual theory – emphasizes that how parents
manage their child’s sexual and aggressive drives in the 1st
few years of life is crucial for healthy personality
development
Id
Ego
Superego
•Largest portion of the mind
•Unconscious, present at birth
•Source of biological needs & desires
•Conscious, rational part of mind
•Emerges in early infancy
•Redirects id impulses acceptably
•The conscience
•Develops from ages 3 to 6 from
interactions with caregivers
Psychoanalytic Perspective: Freud
 Psychosexual stages – During childhood sexual impulses
shift their focus from the oral to the anal to the genital
regions of the body
 If parents strike an appropriate balance, then the child will
grow into a well-adjusted adult
Psychosexual Stage
Period of Development
Oral
Birth – 1 year
Anal
1 – 3 years
Phallic
3 – 6 years
Latency
6 – 11 years
Genital
Adolescence
Psychoanalytic Perspective: Erikson
 Psychosocial theory – emphasized that the ego makes a
positive contribution to development, acquiring attitudes and
skills at each stage that make the individual an active,
contributing member of society
 Basic psychological conflict between positive and negative
occurs at each stage in development
 How the conflict between positive and negative is resolved at
each stage determines if healthy or maladaptive outcomes
occur
Psychoanalytic Perspective: Erikson
Psychosocial Stage
Basic trust v. mistrust
Autonomy v. shame and doubt
Initiative v. guilt
Industry v. inferiority
Period of Development
Birth to 1 year
1–3 years
3–6 years
6–11 years
Identity v. role confusion
Intimacy v. isolation
Generativity v. stagnation
Ego integrity v. despair
Adolescence
Early adulthood
Middle adulthood
Late adulthood
Psychoanalytic Perspective: Erikson
 1st 5 stages parallel Freud, but Erikson added 3 more adult
stages
 Normal development must be understood in relation to each
culture’s life situation
 Child rearing can be understood only in relation to the
competencies valued and needed by an individual’s society
Psychoanalytic Perspective: Strengths
and weaknesses
 Strengths
 Emphasis on the individual’s unique life history
 Inspired research on many aspects of emotional and social
development (infant-caregiver attachment, aggression, sibling
relationships, child-rearing practices, morality, gender roles,
and adolescent identity)
 Weaknesses
 No longer in the mainstream of human development research
 Too focused on the clinical approach, failed to consider other
methods
 Psychosexual stages and ego functioning are so vague that they
are difficult or impossible to test empirically
Behaviorism & Social Learning Theory
 Behaviorism – only directly observable events are
appropriate to study
 Completely disregards anything that cant be directly observed
(like Freud’s id, ego, and superego)
 John Watson – founder of behaviorism, backlash against
psychoanalysis
 Goal: to create an objective science of psychology, disregard
unseen inner workings of the mind
Behaviorism & Social Learning Theory
 Classical conditioning – Showed that a reflex (an
involuntary reaction) could be caused to occur in response to
a formerly unrelated stimulus
 Dog Study:
Behaviorism & Social Learning Theory
 Watson wanted to see if classical conditioning could be applied to
children’s behavior
 “Little Albert” study
 Conditioned a baby to fear a white rat by paring it with a loud noise
 http://www.youtube.com/watch?v=0FKZAYt77ZM
 Concluded that environment is the supreme force in development
 Adults can mold children’s behavior by controlling stimulus-
response associations
 Viewed development as a continuous process, consisting of
gradual increase with age in the number and strength of these
associations
Behaviorism & Social Learning Theory
 Operant conditioning theory (B.F. Skinner)
 The frequency of a behavior can be increased or decreased
 Increased: follow the behavior with a reward called a reinforcer
(food, praise, friendly smile)
 Decreased: follow the behavior with punishment (disapproval or
withdrawal of privileges)
Behaviorism & Social Learning Theory
 Albert Bandura – most influential social learning theorist
 Social learning theory – emphasizes modeling, AKA imitation
or observational learning, as a powerful source of development
 Example: baby claps her hands after seeing her mother do so
 Diverse factors effect children’s motivation to imitate
 Their own history of reinforcement or punishment for the behavior
 The promise of future reinforcement or punishment
 Even vicarious reinforcement or punishment (observing the model
being reinforced or punished)
 Today, social learning theory stresses the importance of cognition,
or thinking
Behaviorism & Social Learning Theory:
Strengths and Weaknesses
 Strengths
 Behavior modification - procedures that combine conditioning
and modeling to eliminate undesirable behaviors and increase
desirable responses
 Example: eliminating bad habits such as smoking and nail biting
 Weaknesses
 Many theorists believe behaviorism and social learning theory
have too narrow of a focus on environmental influences
 Criticized for underestimating people’s contributions to their
own development
Piaget’s Cognitive-Developmental
Theory
 Jean Piaget – most influential researcher on child
development
 Did not believe that children’s learning depends on
reinforcers
 Cognitive-developmental theory – children actively
construct knowledge as they manipulate and explore their
world
 Based on biological concept of adaptation
 Just as structures of the body are adapted to fit with the
environment, structures of the mind also develop to better fit
with, or represent, the external world
Piaget’s Cognitive-Developmental
Theory
 Infancy & early childhood: children’s understanding is
different from adults’
 Example: young babies do not realize that an object hidden
from view (like a favorite toy) continues to exist
 Preschool: thinking is full of faulty logic
 Example: children younger than 7 years commonly say that the
amount of a liquid changes when it is poured into a differentshaped container
 Eventually revise incorrect ideas via ongoing efforts to
achieve equilibrium, or balance, between internal structures
and information they encounter in their everyday worlds
Piaget’s Cognitive-Developmental
Theory
 4 broad stages occur as the brain develops and experiences




expand
Sensorimotor stage (birth-2 years) – cognitive development
begins with the baby’s use of the senses and movements to
explore the world
Preoperational stage (2-7 years) – action patterns evolve into
symbolic but illogical thinking
Concrete operational stage (7-11 years) – cognition is
transformed into more organized, logical reasoning
Formal operational stage (11 years-on) – thought becomes an
abstract, systematic reasoning system
Piaget’s Cognitive-Developmental
Theory: Strengths and Weaknesses
 Strengths
 Children are active learners whose minds consist of rich
structures of knowledge
 Stages sparked research on children’s conceptions of
themselves, other people, and human relationships
 Encouraged development of discovery learning programs which
emphasize direct contact with the environment
 Weaknesses
 Underestimated the competence of infants and preschoolers
 Stages pay insufficient attention to social and cultural influences
on development
 Cognitive changes do not stop occurring in adolescence
Recent Theoretical Perspectives:
Information Processing
 Information processing – views the human mind as a
computer
 A symbol-manipulating system through which information
flows
 Information is presented to the senses during input,
information is actively coded transformed and organized, then
emerges as output a behavioral response
 Regard people as actively making sense of their own thinking
 Continuous change – thought processes are regarded as
similar at all ages but present to a lesser or greater extent
 Uses flowcharts to map the precise steps individuals use to
solve problems and complete tasks
 Example: 5-year-old solving a bridge building problem
 Use the blocks to build a bridge a cross a “river” painted on
the floor too wide for any single block to span
 Child discovers how to counterweight and balance the bridge
Recent Theoretical Perspectives:
Information Processing
 Strengths
 Commitment to rigorous research methods
 Provided precise accounts of how people tackle many cognitive tasks
 Weaknesses
 Better at analyzing thinking into components than putting them
back together into a comprehensive theory
 Virtually ignores aspects of cognition that are not linear and
logical
 Such as imagination and creativity
Recent Theoretical Perspectives:
Developmental Cognitive Neuroscience
 Developmental cognitive neuroscience – studies the
relationship between changes in the brain and cognitive
processing and behavior patterns
 Uses brain-imaging techniques to analyze relationships
between brain functioning, cognitive capacities, and behavior
 Gain knowledge regarding:
 The types of experiences that support or undermine brain
development at various ages
 The brain bases of many learning and behavior disorders
 Example: ADHD has been linked to dysfunction in brain regions such as
the prefrontal cortex
Recent Theoretical Perspectives:
Ethology
 Ethology – concerned with the adaptive, or survival, value
of behavior and its evolutionary history
 Critical period – a limited time span during which the
individual is biologically prepared to acquire certain adaptive
behaviors but needs the support of an appropriately
stimulating environment
 Example: if children are deprived of adequate food or physical
and social stimulation during their early years, will intelligence
be impaired?
Recent Theoretical Perspectives:
Ethology
 Sensitive period – time that is optimal for certain
capacities to emerge and in which the individual is especially
responsive to environmental influence
 Boundaries are less well-defined than those of the critical period
 Development can occur later, but it is harder to induce
Recent Theoretical Perspectives:
Evolutionary Developmental Psychology
 Evolutionary developmental psychology – seeks to
understand the adaptive value of specieswide cognitive,
emotional, and social competencies as those competencies
change with age
 Clarify origins and development of behaviors
 Example: life-threatening risk taking in adolescents and
male-to-male violence may have been adaptive in our
ancestors
 But today, our lifestyles are so radically different that these
behaviors are no longer adaptive
Recent Theoretical Perspectives:
Vygotsky’s Sociocultural Theory
 Sociocultural theory – focuses on how culture is
transmitted on to the next generation
 values, beliefs, customs, and skills of a social group
 Social interaction – necessary for children to acquire the
ways of thinking and behaving that make up a community’s
culture
 Views cognitive development as a socially mediated process
 Children depend on assistance from adults and more expert
peers to tackle new challenges
Recent Theoretical Perspectives:
Ecological Systems Theory
 Ecological systems theory – views the person as developing
within a complex system of relationships affected by multiple
levels of the surrounding environment
 Views the environment as a series of nested structures
 Microsystem – innermost level, activities and interaction patterns
in immediate surroundings (immediate family, school)
 Mesosystem – second level, connections between microsystems
 Exosystem – third level, social settings that do not contain the
person but affect experiences in immediate settings (neighbors,
extended family, board of directors in the workplace)
 Macrosystem – outermost level, cultural values, laws, customs, and
resources
Studying Development
 Hypothesis – prediction about behavior drawn from a
theory
 Research methods
 Basic approach to gathering information
 Systematic observations, self-reports, clinical or case studies,
ethnographies
 Research designs
 Overall plans for research studies
 Permit the best possible test of the investigator’s hypothesis
Common Research Methods:
Systematic Observation
 Naturalistic observation
 In the “field” or natural environment where behavior happens
 Example: observing children in their homes or schools
 Structured observation
 Laboratory situation set up to evoke the desired behavior
 All participants have an equal chance to display behavior
 Used when the behavior of interest is very difficult or
impossible to observe in the “field”
Common Research Methods: SelfReports
 Clinical interview
 Researchers use a flexible, conversation style
 Probe for the participant’s point of view
 Structured interview
 Each participant is asked the same questions in the same way
 Can use questionnaires to assess large numbers of people
Common Research Methods: Clinical,
or Case Study
 Brings together a wide range on information on one person
 Interviews, observations, test scores, etc.
 Well-suited to study types of individuals who are few in
number but vary widely in characteristics
 Example: prodigies – extremely gifted children who attain
adult competence in a field before age 10
Common Research Methods:
Ethnography
 Descriptive, qualitative technique
 Goal: understand a culture or a distinct social group
 Participant observation – researcher spends months, and
sometimes years, in the cultural community, participating in
its daily life
General Research Designs:
Correlational
 Reveals relationships between variables (between characteristics
and behavior or development)
 Does NOT reveal cause-effect!!!
 Correlation coefficient – number that determines strength
and direction of relationship
 Strength
 Size of the number between 1 and -1
 The closer to 1 (positive or negative) the stronger the relationship
 Direction
 Positive: as one variable increases/decreases so does the other
 Negative: as one variable increases the other decreases
General Research Designs:
Experimental
 Can determine cause-effect relationships because researchers
randomly assign participants to two or more treatment
conditions
 Independent variables
 What the researcher expects to cause changes in another
variable
 Directly manipulated/controlled by the researcher
 Dependent variables
 What the investigator expects to be influenced by the
independent variable
 Researcher measures but does not manipulate
General Research Designs:
Experimental
 Random Assignment - unbiased procedure used to assign
participants to treatment conditions
 Increases chances that characteristics will be equally distributed
across conditions
General Research Designs: Modified
Experiments
 Field Experiment
 Capitalize on opportunities for random assignment in natural
settings
 Natural/Quasi-experiment
 Compare treatment conditions that already exist
 Example: gender, age
 Try to match groups as closely as possible
Developmental Research Designs
Same group studied
Longitudinal
at different times
CrossSectional
Differing groups studied at the
same time
Sequential
Several similar cross-sectional
or longitudinal studies at
varying times
Developmental Research Designs:
Longitudinal
 Strengths
 Tracks performance of each person over time, can identify common
patterns and individual differences in development
 Can examine relationships between early and later events and
behaviors
 Weaknesses
 Participants may drop out of the study or move away
 Practice effects – performance may improve as a result of better
test-taking skills and increased familiarity with the test, not because of
factors associated with development
 Cohort effects – results based on one cohort may not apply to
people developing at different times
 Because people born in the same time period are influenced by historical and
cultural conditions of that specific time
Ethics in Lifespan Research
 Institutional Review Boards (IRB)
 Committees that weigh the costs of the research to participants
in terms of inconvenience and possible psychological or physical
injury against the study’s value for advancing knowledge and
improving conditions of life
 If there are risks to participants’ safety and welfare that the
research does not justify, preference is always given to the
participants’ interests
Rights of Research Participants
 Protection from harm
 Informed consent
 Privacy
 Knowledge of results
 Beneficial treatments
 See Table 1.8 page 39, in text book