Chapter 1
INTRODUCTION TO DEVELOPMENTAL
PSYCHOLOGY AND ITS RESEARCH
STRATEGIES
WHAT IS DEVELOPMENT?
• Systematic continuities and changes between
conception to death
– Orderly, patterned and relatively enduring
– Stability, continues to reflect the past
• Developmentalist – anyone who studies the
process of development (represent many
disciplines)
WHAT CAUSES US TO DEVELOP?
• Maturation: biological unfolding of an
individual
– Species-typical biological inheritance
– Individual person’s biological inheritance
• Learning: experiences producing relatively
permanent changes in thoughts, feelings, and
behaviors
WHAT GOALS DO DEVELOPMENTALISTS
PURSUE?
• To Describe: based on observation
– Normative development – typical patterns
– Ideographic development – individual
differences
• To Explain: addresses the “why” of
development
• To Optimize: to help people develop in
positive directions
SOME BASIC OBSERVATIONS ABOUT THE
CHARACTER OF DEVELOPMENT
• A continual and cumulative process
– Change at any phase of life impacts future
• A holistic process: development is due to a
combination of changes in
– Physical growth
– Cognitive aspects of development
– Psychosocial aspects of development
•
Table 1.1 A Chronological Overview of Human Development
SOME BASIC OBSERVATIONS ABOUT THE
CHARACTER OF DEVELOPMENT
• Plasticity: capacity for change in response to
positive or negative life experiences
• Historical/Cultural context
– Historical events may influence
development
– Culture also influences development
HUMAN DEVELOPMENT IN HISTORICAL
PERSPECTIVE
• Child in Premodern Times
– Active infanticide was practiced prior to 4th
century A.D.
– Were seen as possessions having no
rights
– Medieval times – although recognized as a
distinct phase of life, little legal distinction
was made
HUMAN DEVELOPMENT IN HISTORICAL
PERSPECTIVE
• Toward Modern-Day Views on Childhood
– Schooling for moral and religious education
– Reading and writing also important
– Treat children with warmth and affection
– Adolescence recognized in the 20th century
– Child labor laws passed in late 19th century
– Education now compulsory
HUMAN DEVELOPMENT IN HISTORICAL
PERSPECTIVE
• Early philosophical perspectives on childhood
– Original sin (Hobbes): Children are selfish
and must be restrained by society
– Innate purity (Rousseau): Children know
right and wrong, but society corrupts them
– Tabula rasa (Locke): Children are a “blank
slate” – experiences determine outcomes
HUMAN DEVELOPMENT IN HISTORICAL
PERSPECTIVE
• Children as subjects of study: The baby
biographies
– Late 19th century, investigators began to
observe own children and publish the data
• Difficult to compare to each other
• Objectivity is questionable
• Assumptions may have produced bias
• Based on 1 child
HUMAN DEVELOPMENT IN HISTORICAL
PERSPECTIVE
• Origins of a Science of Development
– G. Stanley Hall – founder of developmental
psychology as a research discipline
• First large-scale studies of children
• Developed the questionnaire
• Produced first work to call attention to
adolescence as a unique phase of life
– Sigmund Freud – psychoanalytic theory
HUMAN DEVELOPMENT IN HISTORICAL
PERSPECTIVE
• Origins of a Science of Development
– Theory: set of concepts and propositions
and describe and explain some aspect of
behavior
– Hypotheses – theoretical predictions which
can be tested by collecting data
RESEARCH STRATEGIES: BASIC METHODS
AND DESIGNS
• Careful observation of subjects
• Analysis of collected information
• Use of data to draw conclusions about how
people develop
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• The Scientific Method
– Objective: merits of thinking are based on
data
• Gathering Data: Basic Fact-Finding
Strategies – (measuring what interests us)
– Reliability: consistent information over time
and across observers
– Validity: measures what it is supposed to
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• Gathering Data
– Self-report methodologies
• Interviews/questionnaires
–Structured: Same questions in the
same order
»Allows comparison of responses
•
Table 1.2 Items Comprising Measures of Attitudes Regarding Family Obligations
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• Interviews/Questionnaires
–Limitations:
»Ability to read/comprehend speech
»Issues of honesty and accuracy
»Interpretation of questions
–Strengths
»Gathering large amounts of data
»Confidentiality improves accuracy
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• The clinical method
–Present a task or a stimulus, invite a
response.
–Follow with a tailored question or task
clarifying the response
–Flexible approach considering each
participant to be unique
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• The clinical method
–Strengths
»Large amounts of data collected in
relatively brief periods
»Flexibility
–Limitations
»Comparison of responses
»Subjective interpretation of data
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• Gathering Data
– Observational Methodologies
• Naturalistic observation – observing in
common (natural) settings
–Strengths:
»Very easy
»Shows behavior in everyday life
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• Naturalistic Observation
–Limitations
»Rare or socially undesirable
behaviors may not occur
»Difficult to isolate cause of action
or developmental trend
»Observer may change behavior
(videotape/time may reduce this)
•
Figure 1.1 Social initiations and negative behaviors of abused and nonabused preschool children.
Compared with their nonabused companions, abused youngsters initiate far fewer social
interactions with peers and behave more negatively toward them.
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• Structured observations
–Conducted in the laboratory
»Exposed to a setting
»Observed surreptitiously
»Strength – all participants exposed
to same environment
»Limitations – results may not
represent real life
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• Gathering Data
– Case study: a detailed portrait of a single
individual; can also describe groups
• Strength – depth of information
• Limitations
–Difficult to compare subjects
–Lack of generalizability (results may
not apply to others)
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• Gathering Data
– Ethnography: collect data by living within
the cultural community for an extended
period
• Strengths: understanding cultural
conflicts and impacts on development
• Limitations: subjective, may not be
generalizable
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
• Gathering Data
– Psychophysiological methods: examine
relationship between physiological
responses and behavior
• Heart Rate – compared to baseline,
decrease may indicate interest
• EEG – brain wave activity, showing
arousal states; stimulus detection
RESEARCH METHODS IN CHILD AND
ADOLESCENT DEVELOPMENT
– Psychophysiological methods
• Limitations
–What aspect of stimulus caught
attention?
–Change in physiology may be hunger,
fatigue, or reaction to equipment, not
the stimuli.
•
Table 1.3 Strengths and Limitations of Seven Common Research Methods
DETECTING RELATIONSHIPS: GENERAL
RESEARCH DESIGNS
• The Correlational Design
– 2 or more variables meaningfully related
– Correlation coefficient (r)
• Value, +1.00 to -1.00, indicates strength
• Sign indicates direction
– Positive (+) both variables increase
– Negative (-) one variable increases,
other decreases
•
Figure 1.2 Plot of a hypothetical positive correlation between the amount of violence that children
see on television and the number of aggressive responses they display. Each dot represents a
specific child who views a particular level of televised violence (shown on the horizontal axis) and
commits a particular number of aggressive acts (shown on the vertical axis). Although the
correlation is less than perfect, we see that the more acts of violence a child watches on TV, the
more inclined he or she is to behave aggressively toward peers.
DETECTING RELATIONSHIPS: GENERAL
RESEARCH DESIGNS
• The Correlational Design
– Correlational studies do not show
causation.
• Causal direction of relationship is
unknown
• Relationship could be due to a third,
unmeasured variable
DETECTING RELATIONSHIPS: GENERAL
RESEARCH DESIGNS
• The Experimental Design
– Assesses cause-and-effect relationships
between 2 variables
– Independent Variable: modified or
manipulated by experimenter to measure
its impact on behavior
– Dependent Variable: aspect of behavior
measured in a study, under control of I.V.
DETECTING RELATIONSHIPS: GENERAL
RESEARCH DESIGNS
• The Experimental Design
– Confounding variable: a factor other than
the I.V. that could explain differences in the
D.V.
– Experimental Control
• Control confounding variables
• Random assignment – equal probability
of exposure to each treatment
DETECTING RELATIONSHIPS: GENERAL
RESEARCH DESIGNS
• The Experimental Design
– The Field Experiment: an experiment
taking place in a naturalistic setting.
– The Natural (or Quasi-) Experiment:
measuring the impact of a naturally
occurring event.
• I.V. cannot be manipulated
• Participants are not randomly assigned
•
Figure 1.3 Mean physical aggression scores in the evening for highly aggressive (HA) and less
aggressive (LA) boys under baseline conditions and after watching violent or neutral movies.
ADAPTED FROM LEVENS ET AL., 1975.
•
Table 1.4 Strengths and Limitations of General Research Designs
DETECTING RELATIONSHIPS: GENERAL
RESEARCH DESIGNS
• Cross-Cultural Designs
– Participants from different cultures or
subcultures are observed, tested, and
compared on aspects of development.
• Studies people of different nationalities,
but also groups within the same nation
• Guard against overgeneralization of
research findings
BOX 1.1: FOCUS ON RESEARCH: GENDER
ROLES ACROSS CULTURES
• Are sex differences in behavior due to
biological differences between the sexes?
– Arapesh: males and females taught to be
cooperative, nonaggressive, and sensitive
– Mundugumor: men and women are
aggressive and emotionally nonresponsive
– Tchambuli: males are passive, dependent,
and sensitive, females the opposite
RESEARCH DESIGNS FOR STUDYING
DEVELOPMENT
• The Cross-Sectional Design
– People of different ages are studied at the
same point in time
• Cohort – group of the same age,
exposed to similar environments and
cultural events
•
Figure 1.4 Children’s ability to reproduce the behavior of a social model as a function of age and
verbalization instructions. ADAPTED FROM COATES AND HARTUP, 1969.
RESEARCH DESIGNS FOR STUDYING
DEVELOPMENT
• The Cross-Sectional Design - limitations
– Cohort effects – any differences observed
may be due to cultural or historical factors
that distinguish cohorts, not actual
developmental change.
– Data on individual development
• Each person is measured once, so there
is no data on individual development
RESEARCH DESIGNS FOR STUDYING
DEVELOPMENT
• The Longitudinal Design
– Same participants are observed repeatedly
over a period of time
• Can assess stability of attributes
• Can identify normative developmental
trends
• Can help understand individual
differences in development
RESEARCH DESIGNS FOR STUDYING
DEVELOPMENT
• The Longitudinal Design
– Limitations
• Costly and time-consuming
• Practice effects – improvement due to
familiarity with test or interview
• Selective attrition – participants
remaining in the study may not be a
nonrepresentative sample
RESEARCH DESIGNS FOR STUDYING
DEVELOPMENT
• The Longitudinal Design
– Limitations
• Cross-generational problem – due to
changes in environment, conclusions
may be limited to those who were
growing up while the study was in
progress
RESEARCH DESIGNS FOR STUDYING
DEVELOPMENT
• The Sequential Design
– Selects participants of different cohorts and
follows each cohort over time
• Strengths
–Analysis of cohort effects
–Both cross-sectional and longitudinal
comparisons in same study
–More efficient
•
Figure 1.5 Example of a sequential design. Two samples of children, one born in 1998, and one
born in 2000 are observed longitudinally between the ages of 6 and 12. The design permits the
investigator to assess cohort effects by comparing children of the same age who were born in
different years. In the absence of cohort effects, the longitudinal and cross-sectional comparisons
in this design also permit the researcher to make strong statements about the strength and the
direction of any developmental changes.
RESEARCH DESIGNS FOR STUDYING
DEVELOPMENT
• The Microgenetic Design
– Illuminate processes that promote
developmental change
• Repeatedly expose children ready for a
developmental change to experiences
thought to produce that change
• Monitor behavior as it changes
RESEARCH DESIGNS FOR STUDYING
DEVELOPMENT
• The Microgenetic Design
– Limitations
• Time consuming to track large numbers
of children in such a detailed manner
• Repeated observations may affect the
developmental outcomes being studied
•
Table 1.5 Strengths and Limitations of Four Developmental Designs
ETHICAL CONSIDERATIONS IN
DEVELOPMENTAL RESEARCH
• Research Ethics – standards of conduct to
protect participants from harm
– Informed consent – explanation of all
aspects of research that may affect
willingness to participate
– Benefits to risks ratio – comparison of
possible benefits to costs of research in
terms of harm or inconvenience
ETHICAL CONSIDERATIONS IN
DEVELOPMENTAL RESEARCH
• Research Ethics
– Confidentiality – concealment of identity
with respect to data subjects provide
– Protection from harm – research subjects
have a right to protection from physical or
psychological harm
•
Table 1.6 Major Rights of Children and Responsibilities of Investigators Involved in Psychological
Research
BOX 1.2: APPLYING RESEARCH TO LIFE:
BECOMING A CONSUMER OF RESEARCH
• Need to know how to evaluate the new
findings reported in the media
– How were the data gathered?
– How was the study designed?
– Were the conclusions appropriate for the
design?
– Were participants randomly assigned?