CHAPTER 1
UNDERSTANDING LIFE-SPAN
HUMAN DEVELOPMENT
Learning Objectives
• How do developmental scientists
define development?
• What does the typical path of
development look like across the
life span?
What is Development?
• Systematic changes and
continuities
– In the individual
– Between conception and death
• “Womb to Tomb”
• Three broad domains
– Physical, Cognitive, Psychosocial
Other Developmental Definitions
• Growth: Physical changes that occur
from birth to maturity
• Aging: Positive and negative changes
in the mature organism
• Maturation: The biological unfolding of
the individual genetic plan
• Learning: Relatively permanent
changes due to environmental
experiences
Age Grades, Age Norms, and the Social Clock
• Age Grade: Socially defined age groups
– Statuses, roles, privileges, responsibilities
– Adults can vote, children can’t
• Age Norms: Behavioral expectations by age
– Children attend school
• Social Clock: When things should be done
– Early adulthood – time for 1st marriages
• “Off time” experiences are more difficult
Periods of Development
•
•
•
•
•
Prenatal period: conception to birth
Infancy: birth to 18 to 24 months
Early childhood: end of infancy to 5 or 6 years of age
Middle and late childhood: 6 to 12 years of age
Adolescence: transition from childhood to early
adulthood,12 years of age to 20 years
• Early adulthood: 20 to 40 years of age
• Middle adulthood: 40-65 years of age
• Late adulthood: begins in the 60s and lasts until death
Learning Objective
• How has our understanding of
different periods of the life span
changed historically?
Phases of the Life Span
• Before 1600: Children viewed as miniature
adults
• Modern View: Children innocent, need
protection
• Average life expectancy in 1900 was 47 year
• In 2000 it was 77.5 years
– Females: White=80, Black=76
– Males: White=75, Black=69
• Increasing population - age 65 and older
Learning Objective
• What are the main components of
the nature-nurture issue?
Framing the Nature/Nurture
Issue
• Nature: heredity
– Maturational processes guided by genes
– Biologically based predispositions
– Biological unfolding of genes
• Nurture: environment
– Learning: experiences cause changes is
thoughts, feelings, and behaviors
• Interactionist view: nature & nurture interact
Learning Objectives
• What are the features of the
bioecological model?
• Why is this perspective important
to our understanding of
development?
The Bioecological Model
• Microsystem: Immediate
environment
• Mesosystem: Relationships
• Exosystem: Social Systems
• Macrosystem: Culture
• This is an interactionist model
•
Urie Bronfenbrenner’s bioecological model of development pictures environment as a series of
nested structures. The microsystem refers to relations between the developing person and her
immediate environment, the mesosystem to connections among microsystems, the exosystem
to settings that affect but do not contain the individual, the macrosystem to the broader cultural
context of development, and the chronosystem to the patterning over time of historical and life
events. Researchers face many challenges in studying the developing person in context.
Learning Objectives
• What is the science of life-span
development?
• What are the three goals of
developmental psychology?
• What are the seven assumptions
of the modern life-span
perspective on human
development?
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
Methods of Studying Life-Span
Development
• Historical
– Baby Biographies: Charles Darwin
– Questionnaires: G. Stanley Hall
• Key Assumptions of Modern Life-Span Perspectives
– Lifelong, multidirectional process
– Gain and loss and lifelong plasticity
– Historical/cultural contexts, multiple influences
– Multi-disciplinary studies
Learning Objectives
• What is the scientific “mindset”?
• How is the scientific method used
to study development?
Unique Challenges in
Developmental Research
• Infants and young children
– Attention, instruction, answering
questions may be difficult
• Elderly Adults
– Possible sensory impairments
– Discomfort being studied, tested
Conducting Developmental Research
• Self-reports: interview, questionnaires, tests
• Behavioral Observations (Experiments)
– Naturalistic
• Advantage: natural setting
• Disadvantage: conditions not controlled
– Structured (Lab)
• Disadvantage: cannot generalize to natural
settings
• Advantage: conditions controlled
Learning Objective
• What are the essential features of
the experimental method?
• What sorts of information can be
gathered from this type of study?
• What are its strengths and
weaknesses?
The Scientific (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 scientific method in action
Learning Objective
• What are the important features
of the correlational method?
• What sorts of information can be
gathered from this type of study?
• What are its strengths and
weaknesses?
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
Learning Objective
• What are the advantages and
disadvantages of the crosssectional and longitudinal
designs?
• How does the sequential design
resolve the weaknesses of these
designs?
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
• Cross-sectional and longitudinal studies of development from age 30 to
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
– Take place at time of data collection
– Disadvantage of longitudinal design
•
Conflicting findings of hypothetical cross-sectional and longitudinal studies of
gender-role attitudes. How could the two studies produce different age trends?
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
•
A sequential study. This study begins in 1970 with a group of 30-year-olds studied
longitudinally every 10 years thereafter. In 1980, a second longitudinal study is launched, in
1990 a third, and so on. Notice that at a point in time such as 2000 (blue shading) age
groups can be compared in a cross sectional study. Notice too that 30-year-olds from
different cohorts can be compared (orange shading).
Learning Objective
• What special challenges do
developmental scientists face?
• What challenges arise in studying
development and how can
scientists address these issues?
Issues in Developmental Studies
• Random sampling
– Increases likelihood that sample is
representative of population
• Protecting rights of research participants
– Must assess the benefit to risk balance
• Researcher responsibilities
– Informed consent, debriefing, protection
from harm, confidentiality
Cultural and Subcultural
Sensitivity in Research
• Variety of contexts considered
• Culturally sensitive methods &
measurements
• SES particularly important
• Ethnocentrism