The Psychology of Human
Development
David F. Bjorklund
Why Study Development?
 “The child is the father of man (and the
mother of woman)” - to understand adults,
including ourselves
 To understand human nature
 To foster development and well-being
(optimization)
Goals of Studying Life-Span Development
 Description
 Normal development, individual differences
 Explanation
 Typical and individually different development
 Optimization
 Positive development, enhancing human capacities
 Prevention and overcoming difficulties
What is Development?
 Systematic changes and continuities
 In the individual
 Between conception and death
 “Womb to Tomb”
 Three broad domains
 Physical, Cognitive, Psychosocial
Types of “change over time”
 Ontogeny: changes in the individual over the course of his
or her lifetime
 Phylogeny: development of the species (i.e., evolution)
 Maturation: a biological unfolding of the individual
according to a genetic plan.
 Learning: relatively permanent changes in thoughts,
feelings, or behaviors as a result of experience, that usually
occur over brief periods
 Growth: Physical changes that occur from birth to
maturity
 Aging: Positive and negative changes in the mature
organism
Development: Changes in structure or function
over time
 Structure refers to some substrate of the organism, such as
nervous tissue, muscle, or limbs, or—in cognitive
psychology—the mental knowledge that underlies
intelligence.
 Function denotes actions related to a structure and can
include actions external to the structure being studied, such
as neurochemical or hormonal secretions, and other
exogenous factors that can best be described as
“experience”—that is, external sources of stimulation.
 Development is characteristic of the species and
has its basis in biology. Its general course,
therefore, is relatively predictable. Development
progresses as a result of bidirectional, or
reciprocal, relationship between structure and
function, and can be expressed as:
 structure function.
A Brief History of Childhood
 Childhood as a sociological concept
 Infanticide legal in much of ancient world and common in
Europe through middle ages (abandonment outlawed in
Europe in 1600s)
 Oblation: leaving infants with religious organizations
 Children incorporated into daily lives of adults
 50% of children died before age 5 until 1800s
 Enlightenment: Jean Jacques Rousseau: children are
important in their own right, and are not merely a means to
an end (that is, adulthood).
Literacy and Education
 Postman: invention of moveable type
changed definition of adulthood (being
literate); necessitated schooling and “the
invention” of childhood
Increases in Life Expectancy over the 20th
Century in the U.S.
2000
1990
1980
1970
1960
1950
1940
1930
1920
1910
1900
77
75.5
74
71
69
68
63.5
59
56.5
51.5
49
0
20
40
60
Life Expectancy
80
100
Life Expectancy at Birth for Different Countries:
2000
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Andorra:
83.5
San Marino: 81.1
Japan:
80.7
Sweden:
79.6
Italy:
79.0
United States: 77.1
China:
71.4
Vietnam:
69.3
Iraq:
66.5
Egypt:
63.3
India:
62.5
Brazil:
Cambodia:
South Africa:
Haiti:
Somalia:
Afghanistan:
Uganda:
Botswana:
Angola:
Malawi:
Zambia:
62.9
56.5
51.1
49.2
46.2
45.9
42.9
39.3
38.3
37.6
37.2
Issues in Lifespan Development
 The Stability and Plasticity of Human Behavior: The
Effects of Early Experiences and the Changeability of
Behavior
 Continuity vs. Discontinuity: The “Stages Debate,” or
Understanding How Development Progresses
 Normative vs. Idiographic Approaches: Developmental
Function and Individual Differences
 Nature vs. Nurture: About the Role of Genetics and
Environment in Human Development
The Stability and Plasticity of Human Behavior
 Stability refers to the degree to which people
maintain their same rank order in comparison to
other children with respect to some characteristic
 Plasticity refers to the ability to change as a result
of experience.
Continuity vs. Discontinuity
 Stages of Development
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Qualitative versus Quantitative Differences
Continuity versus Discontinuity
Homogeneity of Cognitive Function
Discontinuous (stage-like) versus Continuous
changes
Some abilities, such as language, are more easily
acquired during a critical, or sensitive, time in
development
Framing the Nature/Nurture Issue
 Nature: heredity(nativism)
 Maturational processes guided by genes
 Biologically based predispositions
 Biological unfolding of genes
 Genetic determinism
 Nurture: environment (empiricism)
 Learning: experiences cause changes is thoughts,
feelings, and behaviors
 Environmental determinism
 Interactionist view: nature & nurture interact
Caspi et al., 2002
 monoamine oxidase A (MAOA) associated
with antisocial behavior in rats and humans
 Gene on X chromosome controls MAOA
(high versus low levels)
 Examined antisocial behavior in boys with
high and low levels of MAOA as function of
childhood maltreatment
Relationship between childhood maltreatment (none,
probable, severe) and MAOA activity (low versus high) on
antisocial behavior.
Composite Index of Antisocial
Behavior
1.25
1
Low MAOA
Activity
High MAOA
Activity
0.75
0.5
0.25
0
-0.25
-0.5
None
Probable
Severe
Childhood Maltreatment
Methods of Studying Life-Span
Development
 Historical
 Baby Biographies: Charles Darwin
 Questionnaires: G. Stanley Hall
 Key Assumptions of Modern Life-Span
Perspectives
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Lifelong, multidirectional process
Gain and loss and lifelong plasticity
Historical/cultural contexts, multiple influences
Multi-disciplinary studies
Conducting Developmental Research
 Self-reports: interview, questionnaires, tests
 Behavioral Observations
 Naturalistic
 Advantage: natural setting
 Disadvantage: conditions not controlled
 Structured (Lab)
 Disadvantage: cannot generalize to natural settings
 Advantage: conditions controlled
Figure 1.2
The Experimental Method
 Three Critical Features
 1. Manipulation of independent variable
 2. Random assignment of individuals to
treatment conditions
 3. Experimental control
 Quasi-Experiment: No random
assignment
The Correlational Method
 Determine if 2 or more variables are related
 Correlation: A measure of the relationship
 Can range from +1.0 to –1.0
 Positive: variables move in same direction
 Negative: variables move in opposite dir.
 No relationship if correlation is 0
 Cannot establish a causal relationship
Figure 1.3
Developmental Research Designs
 Cross-Sectional Designs
 +1 cohorts or age-groups studied
 1 time of testing
 Studying age differences at any one time
 Longitudinal Designs
 1 cohort
 +1 time of testing
 Study changes across time in one cohort
Figure 1.4
Age, Cohort, and Time of Measurement Effects
 Age effects: Changes which occur due to age
 Cohort Effects: Born in one historical context
 Changes due to differences in society
 Disadvantage of cross-sectional design
 Time of measurement effects: Historical
 Takes place at time of data collection
 Disadvantage of longitudinal design
Sequential Designs
 A combination of cross-sectional and longitudinal
designs
 Advantages of both designs
 Gives information about
 Which age-related trends are age effects?
 Which age-related trends are truly cohort effects?
 Which age-related trends are a result of historical
events?
Figure 1.6
“He should have published”
Protecting the Rights of Participants
 Risk to benefit balance of the research
 Researcher responsibilities
 Informed consent
 Debriefing
 Protection from harm
 Confidentiality
Ethical Standards for Research with Children
 Doing research with children involves all the same ethical
considerations when one does research with adults, plus
some additional ones. The principles listed below were
published in the 1990-91 Directory of the Society for
Research in Child Development (SRCD), except for
Principles 15 and 16, first published in the Fall 1991
Newsletter.
 Principle 1. Non-harmful procedures: The investigator
should use no research operation that may harm the child
either physically or psychologically. The investigator is
also obligated at all times to use the least stressful research
operation whenever possible. . . When the investigator is
in doubt about the possible harmful effects of the research
operations, consultation should be sought from others. .
Principle 2. Informed Consent: Before seeking consent or
assent from the child, the investigator should inform the child
of all features of the research that may affect his or her
willingness to participate and should answer the child’s
questions in terms appropriate to the child’s comprehension.
The investigator should respect the child’s freedom to choose
to participate in the research or not by giving the child the
opportunity to give or not give assent to participation as well
as to choose to discontinue participation at any time. . .
Investigators working with infants should take special effort
to explain the research procedures to the parents and be
especially sensitive to any indicators of discomfort in the
infant. . .
Principle 3. Parental consent: The informed consent of
parents, legal guardians or those who act in loco parentis
(e.g., teachers, superintendents of institutions) similarly
should be obtained, preferably in writing. Informed consent
requires that parents or other responsible adults be informed
of all the features of the research that may affect their
willingness to allow the child to participate. This information
should include the profession and institution affiliation of the
investigator. Not only should the right of the responsible
adults to refuse consent be respected, but they should be
informed that they may refuse to participate without incurring
any penalty to them or to the child.
 Principle 4. Additional consent: The informed consent of any
persons, such as school teachers for example, whose interaction
with the child is the subject of the study should also be obtained.
.
 Principle 5. Incentives: Incentives to participate in a research
project must be fair and must not unduly exceed the range of
incentives that the child normally experiences. . . .
 Principle 6. Deception: Although full disclosure of information
during the procedure of obtaining consent is the ethical ideal, a
particular study may necessitate withholding certain information
or deception. Whenever withholding information or deception is
judged to be essential to the conduct of the study, the
investigator should satisfy research colleagues that such
judgment is correct. . .
 Principle 7. Anonymity: To gain access to institutional records,
the investigator should obtain permission from responsible
authorities in charge of records. Anonymity of the information
should be preserved and no information used other than that for
which permission was obtained.
 Principle 8. Mutual responsibilities: From the beginning of
each research investigation, there should be clear agreement
between the investigator and the parents, guardians or those who
act in loco parentis, and the child, when appropriate, that defines
the responsibilities of each. The investigator has the obligation
to honor all promises and commitments of the agreement.
 Principle 9. Jeopardy: When, in the course of research,
information comes to the investigator’s attention that may
jeopardize the child’s well-being, the investigator has a
responsibility to discuss the information with the parents or
guardians and with those expert in the field in order that they
may arrange the necessary assistance for the child.
 Principle 10. Unforeseen consequences: When research
procedures result in undesirable consequences for the participant
that were previously unforeseen, the investigator should
immediately employ appropriate measures to correct these
consequences, and should redesign the procedures if they are to
be included in subsequent studies.
 Principle 11. Confidentiality: The investigator should keep in
confidence all information obtained about research participants.
The participants’ identity should be concealed in written and
verbal reports of the results, as well as in informal discussion
with students and colleagues. .
 Principle 12. Informing participants: Immediately after the data
are collected, the investigator should clarify for the research
participant any misconceptions that may have arisen. . .
 Principle 13. Reporting results: Because the investigator’s
words may carry unintended weight with parents and children,
caution should be exercised in reporting results, making
evaluative statements, or giving advice.
 Principle 14. Implications of findings: Investigators should be
mindful of the social, political and human implications of their
research and should be especially careful in the presentation of
findings from the research. This principle, however, in no way
denies investigators the right to pursue any area of research or
the right to observe proper standards of scientific reporting.
 Principle 15. Scientific misconduct: Misconduct is defined as
the fabrication or falsification of data, plagiarism,
misrepresentation, or other practices that seriously deviate from
those that are commonly accepted within the scientific
community for proposing, conducting, analyzing, or reporting
research. It does not include unintentional errors or honest
differences in interpretation of data. The Society . . . will not
tolerate the presence of scientific misconduct among its
members. It shall be the responsibility of the voting members of
Governing Council to reach a decision about the possible
expulsion of members found guilty of scientific misconduct.
 Principle 16. Personal misconduct: Personal misconduct that
results in a criminal conviction of a felony may be sufficient
grounds for a member’s expulsion from the Society. . .
 Source: As followed by members of the Society for Research in
Child Development. Adapted from Winter 1990 SRCD
Newsletter. Reprinted by permission.
Theories of Development
 Mechanistic theories liken people to machines, such as
the mind-as-a-computer model of information-processing
approaches.
 Learning theories (operant & classical conditioning;
social learning theory)
 Information-processing theory
 Organismic theories take a more “biologic” (nature) view
of development, seeing people as whole beings who cannot
be understood by decomposing them into their constituent
parts.
 Piaget’s theory of cognitive development
 Psychoanalytic theories of Freud and Erikson
Learning Theories: Classical Conditioning
 Behaviorism: Conclusions should be based on
observable behavior
 Tabula Rasa: Environmental view
 Association learning
 UCS: built-in, unlearned stimulus
 UCR: automatic, unlearned response
 CS: causes learned response
 CR: learned response
Figure 2.2
Learning Theories: Operant Conditioning
 Probability of behavior based on environmental
consequences
 Reinforcement
 Pleasant consequence
 Increases probability
 Punishment
 Decreases probability
 Unpleasant, aversive
Bandura: Social Cognitive Theory
 Formerly called social learning theory
 Humans think, anticipate, believe, etc.
 Cognitive emphasis: observational learning
 BoBo doll studies
 Model praised or punished
 Child learned to imitate rewarded model
 Vicarious reinforcement
 Reciprocal determinism
Learning Theory: Strengths & Weaknesses
 Strengths
 Precise and testable theory
 Carefully controlled experiments
 Practical applications across lifespan
 Weaknesses
 Inadequate account of lifespan changes
 Ignored genetic and maturational processes
Piaget: Cognitive Developmental Theory
 Intelligence: Ability to adapt to environment
 Constructivism: Understanding based on
experience
 Interactionist
 Both biological maturation and experience
required for progress
 At each new stage, children think in a qualitatively
different way
Cognitive Developmental Theory
 Strengths
 Well-accepted by developmentalists
 Well-researched, mostly supported
 Influenced education and parenting
 Weaknesses
 Ignores motivation and emotion
 Stages not universal – esp. last one
Freud: Psychoanalytic Theory
 Instincts and unconscious motivation
 Id, Ego, and Superego formed from psychic energy
(Libido)
 Id: Instinctual nature of humans
 Ego: rational and objective
 Superego: internalized moral standards
 A dynamic personality system
 Regular conflicts between the three parts
Freud’s Psychosexual Development
 Child moves through 5 stages
 Stages result from conflict between Id & Superego
 Conflict creates anxiety
 Ego defends against anxiety with defense mechanisms
 Early experiences have long-term effects on personality
Erik Erikson
 Most influential neo-Freudian
 Some differences with Freud
 Less emphasis on sexual urges
 More emphasis on rational ego
 More positive and adaptive view of human nature
 Believed development continues through adulthood
Contextual/Systems Theories
 Lev Vygotsky: Sociocultural perspective
 Cognitive development is a social process
 Problem solving aided by dialogues
 Gottlieb: Evolutionary/Epigenetic Systems
 Genes, neural activity, behavior, and
environment mutually influential
 Normal genes and normal early experiences
most helpful
Sociocultural Perspectives on Cognitive
Development
 “Cognitive development is an active constructive process
that involves beings who are evolutionarily predisposed to
live and learn in social context with other ‘like-minded’
beings. They are like-minded in terms of both the
neurological system available and the social requirements
that are in place”
 Mary Gauvain, 2001
Lev Vygotsky
 Development should be evaluated from the
perspective of four inter-related levels:
 Phylogenetic
 Ontogenetic
 Microgenetic
 Sociohistorical
Tools of Intellectual adaptation
 Methods of thinking and problem-solving
strategies that children internalize from their
interactions with more competent members of
society that permit them to use basic mental
functions more adaptively
Chinese and English number words from 1 to 20

Number
Chinese word
English word
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
yee
uhr
sahn
suh
woo
lyo
chee
bah
jyo
shi
shi yee
shi uhr
shi shan
shi suh
shi woo
shi lyo
shi chee
shi bah
shi jyo
ershi
one
two
three
four
five
six
seven
eight
nine
ten
eleven
twelve
thirteen
fourteen
fifteen
sixteen
seventeen
eighteen
nineteen
twenty
Median level of counting (highest number reached)
by age for Chinese and U.S. preschoolers (Miller et
al., 1995
Median Counting Level
100
80
60
China
US
40
20
0
3
4
Age in Years
5
Zone of Proximal Development
 ZPD: the difference between a child’s actual
developmental level as determined by independent
problem solving and his or her level of potential
development determined through problem solving under
adult guidance or in collaboration with more capable peers.
 Scaffolding: When experts are sensitive to abilities of a
novice and respond contingently to the novice’s responses
in a learnikng situation, so that the novice gradually
increases his or her understanding of a problem
Apprenticeship in Thinking
 Guided participation refers to adult-child interactions, not
only during explicit instruction, but also during the more
routine activities and communication of everyday life.
Guided participation is “the process and system of
involvement of individuals with others, as they
communicate and engage in shared activities” (Rogoff et
al., 1993, p.6)
Some functions of shared remembering in children’s memory
development from Gauvain, 2001)
Children learn about memory process, for example, strategies
Children learn ways of remembering and communicating
memories with others, for example, narrative structure
Children learn about themselves, which contributes to the
development of the self-concept
Children learn about their own social and cultural history
Children learn values important to the family and the community,
that is, what is worth remembering
Promotes social solidarity
Developmental Systems Approach
 Development proceeds as a result of the bidirectional
interaction between structure and function over time at all
levels of organization, from the genetic through the
cultural.
 Epigenesis: “any gene-regulating activity that doesn’t
involve changes to the DNA code and that can persist
through one or more generations” (Pennisi, 2001)
 Genetic activity (DNA <-> RNA <-> proteins) <->
structural maturation <-> function, activity
Preformationist view of development
QuickTime™ and a
TIFF (U ncompres sed) decompressor
are needed to see this picture.
 Genetic activity (DNA <-> RNA <-> proteins) <->
structural maturation <-> function, activity
A simplified schematic of the developmental systems
approach, showing a hierarchy of four mutually interacting
components (from Gottlieb)
Newly hatched ducklings approach maternal call. Any role of
auditory experience? (Gottlieb)
Prior to hatching:
Remove mother: Approach maternal call
Remove clutch mates: Approach maternal call
Prevent from vocalizing in egg: No preference
Transactional Model of Development
 Development is seen as the continuous and bidirectional
interaction between an active organism and with a unique
biological constitution and a changing environment.
Zeskind & Ramey (1981)
 High-risk rural population
 Experimental (daycare) group vs. Control group
 Biologically normal vs. Fetally malnourished
 Stanford-Binet IQ scores at 36 months (from Zeskind &
Ramey, 1981)
IQ Scores at 36 months
Biologically
normal
Fetally
malnourished
 Exper’tal group
98.1
96.4
 Control group
84.7
70.6