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UNDERSTANDING LIFE-SPAN HUMAN DEVELOPMENT
LEARNING OBJECTIVES
After students have read and studied the material in this chapter, they should be able to answer the
following questions:
1. What is development? What processes underlie developmental changes across the life span?
2. How has our understanding of different periods of the life span changed during the past three
centuries?
3. What are the three goals of life-span developmental psychology?
4. What is the scientific method and how is it used to study development?
5. How do studies using self-report measures differ from those using behavioral observations?
6. What are the key variables used when conducting an experiment? Also, what differentiates an
experiment from a quasi-experiment?
7. What are the premise, strengths, and weaknesses of the correlational method?
8. What are the advantages and disadvantages of the cross-sectional, longitudinal, and sequential
research designs?
9. What ethical considerations must be made when conducting research with human subjects?
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CHAPTER OUTLINE
I.
What is development?
Systematic continuities and changes (gains and losses) from conception to death
A. A Working Definition (of development)
1. Physical development-- growth of body, physiological change
2. Cognitive development-- changes in perception, language, learning, memory
3. Psychosocial development -- changes in personality, emotions
4. Growth-- physical changes from conception to maturity
5. Biological aging-- deterioration of organisms
6. Aging—positive and negative changes in maturing organism
B. Developmental Processes
1. Maturation-- biological unfolding
2. Learning-- experiential influences
3. Environment-- external physical and social conditions
II.
How do people view the life span?
A. Age grades, age norms, and the social clock
1. Age grades-- status, roles, privileges, and responsibilities based on age group
2. Age norms-- expectations based on age grades
a. Social clocks-- sense of timing for life transitions
b. “Off time” (vs. “on time”) events have more negative impact
B. Historical changes in phases of the life span
1. Childhood
a. premodern times-- children thought of a miniature adults, harsh treatment
(many of these believes are inaccurate myths)
2. Adolescence
a. 17-18th centuries-- need for educated work force
b. 20th century-- entrance to adulthood further delayed
3. Adulthood
a. longer life expectancy
b. baby boom generation born between 1946-1964
c. middle age as distinct period
d. social security, Medicare introduced
e. age different meaning for each historical era
III.
What is the science of life-span human development?
A. Goals of study
1. Description of human development
a. normal development
b. variations-- individual differences
2. Explanation of human development
3. Optimization of human development
B. Origins
1. Observations of own children-- Charles Darwin’s baby biographies
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2. More objective study-- G. Stanley Hall’s questionnaires
a. Hall calls adolescence a time of “storm and stress”
C. Today's life-span perspective
1. Development is a lifelong process
2. Development is multidirectional
3. Development involves both gain and loss
4. Life-long plasticity in human development
5. Development is shaped by its historical/cultural context
6. Development is multiply influenced
7. Understanding development requires multiple disciplines
IV.
How is developmental research conducted?
A. The scientific method
1. Method is an attitude of systematic observation
2. Theory develops from observations
3. Hypotheses are predictions generated to test theory
B. Data collection
1. Self-reports
a. often standardized interviews, questionnaires, or tests
b. cannot be used on infants, those who cannot read
c. respondents may falsely present themselves in positive manner
2. Behavioral observations
a. naturalistic observation-- behaviors in everyday life
b. structured observation-- create conditions to elicit a behavior
c. meta-analysis-- analytical synthesis of other studies
C. General research methods
1. The experimental method
a. independent variable-- manipulated by experimenter
b. dependent variable-- behavior affected by independent variable
c. critical features of any true experiment
i. manipulation of independent variable
ii. random assignment to treatment conditions-- ensures groups
more similar
iii. experimental control-- hold factors constant
d. experiments-- used to determine cause
e. quasi-experiment—nonrandom assignment to treatment groups
2. The correlational method
a. correlation coefficient assesses extent that individuals’ scores on one
variable systematically related to scores on another
b. involves calculation of correlation coefficient (+1.0 to -1.0)
c. no conclusive cause-effect relationships
i. direction of causality may be reversed
ii. third variable may cause observed association
iii. need convergence of many studies for conclusions
E. Developmental research designs
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1. Cross-sectional design
a. different age groups measured at same time
b. provides information about age differences
2. Longitudinal design
a. same group measured repeatedly
b. provides information on age changes
3. Age, cohort, and time of measurement effects
a. age effect-- effect of getting older
b. cohort effect-- effect of being born in one particular historical context
c. time of measurement effect-- effect of current historical event on research
4. Strengths and weaknesses of the cross-sectional design
a. Can determine cohort differences in behavior
b. Age effects and cohort effects are confounded
c. Relatively fast and inexpensive to conduct
d. No information about development of individuals
5. Strengths and weaknesses of the longitudinal design
a. Can indicate individual age changes in behavior
b. Can show relationships between early and later behavior
c. Center on only one cohort group
d. Age effects and time of measurement effects are confounded
e. Costly and time-consuming
f. Initial questions and measures may later prove uninteresting or inadequate
g. Loss of participants-- leads to smaller, less representative sample
h. Participants can be affected by repeated testing
6. Sequential designs: The best of both worlds
a. Combines cross-sectional and longitudinal approaches
b. Can separate age effects, time of measurement effects, and
cohort effects
c. Costly and complex
V.
What problems arise in studying development?
A. Choosing samples
1. Sample-- group chosen for study
2. Population-- entire well-defined group
3. Random sampling increases generalizability to populations
B. Protecting the rights of research participants
1. Research ethics
a. guidelines from groups
i. APA and SRCD guidelines
ii. human-subjects review committees
b. investigator’s ethical responsibilities
i. informed consent
ii. debriefing
iii. protection from harm
iv. confidentiality
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