Chapter 2:
The Science
of Life-Span
Development
McGraw-Hill © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
Theories
of
Development
• All scientific knowledge comes from scientific
investigation – a four-step process
– Identify a problem to be studied
– Collect data or research information
– Analyze the data
– Draw conclusions
• Diverse but complimentary theories are used
for explaining life-span development:
– Psychoanalytic theories
– Cognitive theories
– Ethological theories
– Ecological theories
Psychoanalytic Theories:
• Freud’s Psychosexual Theory
– Personality has 3 parts
– There are 5 stages of psychosexual development
– Oedipus complex allows child to identify with
same-sex parent
– Fixation is an unresolved conflict during a stage
of development
• Today’s focus is more on cultural experiences and
less on sexual instincts
Phallic
Stage
Child’s
pleasure focuses on
genitals
Figure 2.1
Latency
Stage
Child
represses sexual interest
and develops social and intellectual
skills
Anal Stage
Child’s
pleasure focuses on
anus
Genital
Stage
A time of
sexual reawakening;
source of sexual
pleasure becomes someone
outside of the family
Oral Stage
Infant’s pleasure
centers on mouth
Freudian Stages
6 yrs to puberty
Birth to 1½ yrs
1½ to 3 yrs
Puberty onward
3 to 6 years
• Erikson’s Psychosocial Theory:
– There are 8 stages of psychosocial development
– Each has a unique developmental task
– Developmental change occurs throughout life span
• Key points of psychoanalytic theories:
– Early experiences and family relationships are
very important to development
– Unconscious aspects of the mind are considered
– Personality is best seen as a developmental process
Erikson’s Stages Developmental Period Trust vs Mistrust Infancy (first year)
Autonomy vs shame & doubt
Infancy (1 to 3 years)
Initiative vs guilt Early childhood (3 to 5 years)
Industry vs inferiority Middle and late childhood
Identity vs identity confusion
Adolescence (10 to 20 years)
Intimacy vs isolation Early adulthood (20s, 30s)
Generativity vs stagnation
Middle adulthood (40s, 50s)
Integrity vs despair Late adulthood (60s onward)
Figure 2.2
Erikson’s Eight Life-Span Stages
Cognitive theories:
• Piaget’s cognitive developmental theory
– Stresses conscious mental processes
– Cognitive processes are influenced by
biological maturation
– Four stages of cognitive development
in children
– Assimilation and accommodation underlie
how children understand the world, adapt
to it, and organize their experiences
Preoperational Stage:
The child begins to represent the world with words and images. These words and images reflect increased symbolic thinking and go beyond the connection of sensory information and physical action.
Formal Operational Stage
The adolescent reasons in more abstract idealistic and logical ways.
Sensorimotor Stage:
The infant constructs an understanding of the world by coordinating sensory experiences with physical actions: progressing from reflexive, instinctual action at birth to the beginning of symbolic thought toward end of the stage.
Concrete Operational Stage:
The child can now reason logically about concrete events and classify objects into different sets.
Figure 2.3
11–15 years of age
through adulthood
Birth to 2 years of age
2 to 7 years of age
7 to 11 years of age
Piaget’s Four Stages of Cognitive Development
• Vygotsky’s sociocultural cognitive theory
– Children actively construct their knowledge
– Social interaction and culture guide cognitive
development
– Learning is based upon inventions of society
– Knowledge is created through interactions with
other people and objects in the culture
– Less skilled persons learn from the more skilled
• Information-processing theory
– Compares computers to the human mind
– Thinking is information processing
Information is taken into brain
Information gets processed, analyzed, and stored until use
OUTPUT INPUT
Information is used as basis of behaviors and interactions
Information-Processing Theory
math
history religion
geography
science
literature
Behavioral and social cognitive theories:
• Pavlov’s classical conditioning includes
conditioned and unconditioned responses
• Watson applies association and generalization
• Operant conditioning focuses on positive and
negative reinforcement
• Social cognitive theory focuses on observation
and imitation
• Ethological theory includes imprinting and
attachment
Classical
Conditioning
Generalization
Operant Conditioning
What are the reinforcements to achieve?
What happens when there are no controls or reinforcement?
Task: Learn to read
Environment Person
(cognitive)
Behavior
Bandura’s Social Cognitive Model
Figure 2.4
Bandura’s Modeling/Imitation
Child observes someone admired
Child imitates behavior
that seems rewarded
• Urie Bronfenbrenner’s ecological theory:
– Environmental factors influence development
– 5 environmental systems affect life-span
development
• Eclectic theoretical orientation:
– Selects features from other theories
– No one theory has all the answers
– Each theory can make a contribution to
understanding life-span development
Exosystem Mesosystems
Macrosystem
Family School & classroom
Religion & groups
Peer group
Chronosystem
School system
Political philosophy
Figure 2.5
Bronfenbrenner’s
Ecological Theory
of Development
Research
in
Life-Span
Development
• Types of research:
– Descriptive: observes and records
behavior
• Laboratory research
• Naturalistic observation
• Surveys and interviews
• Standardized tests
• Case studies
• Life-history records
• Physiological measures
Figure 2.8
0
25
5
30
15
10
20
Girls Boys
Percentage parent–child interactions in which the parent explained science concepts
Parents’ Explanations of Science to Sons and Daughters at a Science Museum
– Correlational research
• Measures relationships; not the same
as causation
– Experimental research
• Independent variable gets manipulated
• Dependent variable is the resulting change
• Experimental group is manipulated
• Control group serves as the “norm”
for comparison
Other factors, such as genetic
tendencies, poverty, and sociohistorical
circumstances Children’s lack of self-control
Permissive parenting
Children’s lack of self-control
Permissive parenting
Permissive parenting
Children’s lack of self-control
and
causes
both
cause
causes
Observed correlation: as permissive parenting increases, children’s self-control decreases
Figure 2.9
Possible Explanations for Correlational Data
Newborns’ breathing and sleeping patterns
Control group
(no aerobic exercise)
Participants randomly assigned to experimental and control groups
Dependent variable
Independent variable
Experimental group
(aerobic exercise)
Principles of Experimental Research
Figure 2.10
Group 2 Time playing video
games: 6 hours
each day
More aggressive
and antisocial
More playful
and sociable
Time playing video
games: 2 hours
each day
Group 1
• Time-span research
– Focus on the relation of age to some other
variable across the life span (e.g., memory)
– Cross-sectional approach compares different
age groups at one time
– Longitudinal approach studies a group over a
period of time
– Sequential approach combines longitudinal
and cross-sectional approaches
– Cohort effects: due to time or era of birth but
not due to one’s actual age
Facing Up to
Research Challenges
• Conducting Ethical Research
– Informed consent: participants give informed
consent and participation is voluntary
– Confidentiality of participants’ information
– Participants’ rights will be observed
– Debriefing after the experiment
– Deception: researchers ensure any deception
will not harm the participants
• Minimize bias:
– Gender bias is based on preconceived ideas
about the abilities and differences between
men and women; research affects how people
think about men and women
– Cultural and ethnic bias
• Life-span research needs to include more
diverse groups of people
• Avoid ethnic gloss in research
• Being a Wise Consumer of Information – Media only publishes parts of research when
of public interest
– All information for public consumption may be
• Oversimplified, condensed with few details
• Distorted or exaggerated
– People must consider information carefully
• Separate group from individual outcomes
• Do not overgeneralize from small sample
• Look for additional information on a study
• Do not attribute causes when none exist
• Evaluate the source of information
The End