1. CHAPTER 1 UNDERSTANDING LIFESPAN HUMAN DEVELOPMENT

2. Learning Objectives
How do developmental scientists define development?
What does the typical path of development look like across the lifespan?

3. Systematic changes and continuities in an individual
What Is Development?
Systematic changes and continuities in an individual
Occur between conception and death
From “womb to tomb”
Changes and continuities occur in three broad domains
Physical
Cognitive
Psychosocial
Physical development - growth of body and organs, functioning of the physiological systems including the brain, physical aging, changes in motor abilities
- Cognitive development – perception, language, learning, memory, problem solving, etc.
- Psychosocial development – personal and interpersonal aspects of development, such as motives, emotions, personality traits, interpersonal skills and relationships, and roles in family and society

4. What Is Development?
Development involves gains, losses, neutral changes, and continuities in each phase of the lifespan
Includes growth
Physical changes that occur from conception to maturity
Includes stability
Includes aging
Range of positive and negative physical, cognitive, and psychosocial changes
Biological aging
Deterioration that leads inevitably to death
Traditional view of development was “gain-stablility-loss” model
- Growth in early life, stability in early and middle adulthood, and declines associated with accumulated effects of aging in later life
Growth - the physical changes that occur from conception to maturity
Biological aging - deterioration of organisms that leads inevitably to their death
Modern developmental view
Developmental change at any age involves both gains and losses.
Children gain many cognitive abilities as they get older, but they also lose self-esteem and become more prone to depression.
Some cognitive abilities and types of knowledge and expertise hold steady or even grow during adulthood.
Aging is not solely loss: Adults age 60 and older score higher on vocabulary tests than adults ages 18 to 30.

6. Conceptualizing the Lifespan
Age grade: socially defined age group in a society
Confers statuses, roles, privileges, responsibilities
Rites of passage mark transitions
Age norms: behavioral expectations by age
Basis for the social clock, which influences
Our sense of when things should be done
Our adjustment to life transitions
Age norms in our society have weakened
Age Grade: Socially defined age group in a society
Confers statuses, roles, privileges, responsibilities
-Examples: age grading in schools, adult privilege/responsibility of voting
Rites of passage mark transition from one age grade to another
- Especially in transition from childhood to adulthood
- Examples: body painting, circumcision, instruction in sexual practices, tests of physical skill, celebrations (bar mitzvah, bat mitzvah, quinceañera)
Age Norms: Behavioral expectations by age
-Examples: appropriate age to drink alcohol, go to school, marry, or retire
-Age norms are the basis for the social clock
The social clock influences
-A person’s sense of when things should be done as dictated by age norms
How a person adjusts to life transitions
--“Off time” experiences are more difficult
-Age norms in our society have weakened – it is less clear when one should do something, such as marry or retire.

7. Conceptualizing the Lifespan
Conceptualizations of the lifespan vary from culture to culture and from subculture to subculture
Ethnicity
Classification or affiliation with a group based on common heritage or traditions
Ethnic groups have different age norms and different developmental experiences
Socioeconomic status (SES)
Standing in society based on such indicators as occupational prestige, education, and income
Can influence age at which milestones of adulthood are reached
Conceptualizations of the life span vary from culture to culture and from subculture to subculture.
- Ethnicity
- Classification or affiliation with a group based on common heritage or traditions
-Ethnic groups have different age norms and different developmental experiences
-- African American, Hispanic American, Native American, Asian American, and European American individuals sometimes hold different age norms and have different developmental experiences as a result.
--Within each group there are immense variations associated with such factors as specific national origin, length of time in North America, degree of integration into mainstream society, language usage, and socioeconomic status
- Socioeconomic status (SES)
-Standing in society based on such indicators as occupational prestige, education, and income
--Can influence age at which milestones of adulthood are reached
--Generally, individuals from lower-income families tend to reach milestones of adulthood such as starting work, marrying, and having children earlier than those from middle-income and upper-income families.
--Researchers have determined that children in economically disadvantaged environments may be asked to grow up faster than middle-class children and to assume adultlike responsibilities in the family
earlier than those from middle-income and upper-income families.

8. Learning Objective
How has our understanding of different periods of the lifespan changed historically?

9. Phases of the Lifespan in History
Childhood: view emerged in the 17th century of children as innocents to be protected and nurtured
Adolescence: emerged as a distinct phase of the lifespan in the late 19th, early 20th centuries
Emerging adulthood: the most recently defined phase, from age 18 to age 29
Middle age: recognized in the mid-20th century
Old age: defined in the 20th century
Childhood: View emerged in the 17th century of children as innocents to be protected and nurtured.
Prior to the 17th century, children were seen as miniature adults.
Adolescence: Emerged as a distinct phase of the life span in the late 19th, early 20th centuries
- Transitional period between childhood and adulthood that begins with puberty and ends when the individual has acquired adult competencies and responsibilities
Emerging adulthood: The most recently defined phase of the life span, from age 18 to age 29
-Young people are between adolescence and full-fledged adulthood (see Exploration Box 1.1)
Middle age: Recognized in the mid-20th century
-Between early adulthood and old age when the nest is emptied of children
Old age: Defined in the 20th century
-A period of retirement (previously people worked until they died)

10. Development in the Future
Life expectancy
The average number of years a newborn can be expected to live
In the early 21st century, a newborn’s life expectancy is 78 years
81 for a white female
77 for a black female
76 for a white male
70 for a black male
Differences between women and men and between races have narrowed.
Differences between high and low SES groups have widened

11. Learning Objectives
What are the main elements of the nature-nurture issue?
How does the bioecological model of development address the nature-nurture issue?

12. The Nature-Nurture Issue in Development
Nature: the influences of heredity
Emphasis upon the process of maturation
Biological development according to a genetic plan
Nurture: the influences of environment
Emphasis upon learning
Experiences cause changes in thoughts, feelings, and behaviors

13. The Ecology of Development
Urie Bronfenbrenner proposed a bioecological model to explain how biology and environment interact in development
Microsystem: immediate environment
Mesosystem: linkages between microsystems
Exosystem: linkages of social systems
Macrosystem: larger cultural context
Chronosystem: changes occur in a time frame

14. Caption: 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.

15. Learning Objectives
What goals guide the work of developmental researchers?
What are some of the key events in the history of the study of lifespan development?
What are the key assumptions of the modern-day lifespan perspective?

16. Goals of Studying Lifespan Development
Description
Normal development and individual differences
Explanation
Typical human development and individually different development
Optimization
Positive development and enhanced capacity
Preventing and overcoming difficulties
Description
Explain normal development and individual differences or variations in development
Explanation
Explain why humans develop as they typically do and why some individuals develop differently than others.
Optimization
Explain how to foster positive development and how capacity can be enhanced
Explain how to prevent developmental difficulties and how to overcome developmental problems

17. Applying Research on Development
Evidence-based practice
Used by teachers, mental health professionals, nurses, other helping professionals
The practice of using research-based methods and proven curricula or treatments

18. The History of Studying Lifespan Development
The first scientific investigations
Baby biographies
The most influential: Charles Darwin
G. Stanley Hall
The founder of developmental psychology
Developed the questionnaire
Suggested adolescence is a time of storm and stress

19. Modern-Day Lifespan Perspective
Development is a lifelong process
Development is multidirectional
Development involves both gain and loss
Development is characterized by lifelong plasticity
Development is shaped by historical-cultural context
Development is multiply influenced
Development must be studied by multiple disciplines
Development is a life-long process.
- We change throughout the life span and development in any period of life is best seen in the context of the whole life span.
Development is multi-directional.
-Different capacities show different patterns of change over time; different aspects of human functioning have different trajectories of change
Development involves both gain and loss.
-Gain and loss are intertwined during every phase of the life span. Baltes believed that gain inevitably brings with it loss of some kind, and loss brings gain—that gain and loss occur jointly.
Development is characterized by lifelong plasticity.
-Plasticity refers to the capacity to change in response to both positive and negative experiences.
-Example: Child development can be damaged by a deprived environment and optimized by an enriched one.
-Plasticity continues into later life — the aging process is not fixed but rather can be altered considerably depending on the individual’s experiences.
-Physical exercise and mental stimulation can result in changes in neurochemistry, the formation of new connections among neurons, and, even new neurons in the hippocampus of the brain—even an aging brain.
Development is shaped by historical-cultural context.
-The key point of Bronfenbrenner’s bioecological model of development
-Illustrated by the work of Glen Elder and colleagues who studied how the Depression affected children and adolescents.
Development is multiply influenced.
-Human development is the product of many interacting causes—both inside and outside the person, both biological and environmental.
-Some influences are experienced by all humans at similar ages, others are common to people of a particular generation, and still others are unique to the individual
Development must be studied by multiple disciplines.
-Psychologists, biologists, neuroscientists, historians, economists, sociologists, anthropologists – all have perspectives, tools, and contributions to our understanding of human development.

20. Learning Objectives
What characterizes the scientific method used by those who study lifespan development?
How do researchers use theory?
What characterizes a good theory?

21. The Scientific Method
The scientific method is an attitude
Believe the data, the findings of research
The scientific method involves a process of generating ideas and testing them by making observations
Preliminary observations provide ideas for a theory
Theories generate hypotheses

22. The Scientific Method
Theory
A set of concepts and propositions intended to describe and explain phenomena
Example: Jean Piaget’s theory to describe children’s cognitive development
Theories generate hypotheses
Predictions that can be tested regarding a particular set of observations

23. Theory in the Scientific Method
Theories generate hypotheses
Hypotheses are tested through observations
New observations indicate which theories are supported or should be revised or discarded
A good theory should be
Internally consistent
Falsifiable
Supported by data
Theories generate hypotheses
Hypotheses are tested through observations
New observations indicate which theories are supported or should be revised or discarded
A good theory should be
-Internally consistent. Its different parts and propositions should hang together and should not generate contradictory hypotheses.
-Falsifiable. It can be proved wrong; that is, it can generate testable hypotheses that can be studied and either supported or not supported by data. If a theory is vague or generates contradictory or ambiguous hypotheses, it cannot guide research, cannot be tested, and therefore will not be useful in advancing knowledge.
-Supported by data. A good theory should help us better describe, predict, and explain human development; that is, its predictions should be confirmed by research results.

24. Caption: The scientific method in action

25. Learning Objectives
How do developmentalists collect data?
What methods do developmental scientists use to examine the relationships among the variables that affect development?

26. Best approach is to study a random sample
Sample Selection
A research study focuses on a research sample for the purpose of generalizing to a larger population from which the sample is drawn and about which conclusions can be made
Best approach is to study a random sample
Identify the population and use random means to select a portion to be studied
A research study focuses on a research sample for the purpose of generalizing to a larger population from which the sample is drawn and about which conclusions can be made.
-Sample: the group of individuals studied
-Population: a well-defined specific group
--Example: premature infants
Best approach is to study a random sample.
-Identify the population and use random mean to select a portion to be studied

27. Data Collection Methods - Verbal Reports
Use interviews, written questionnaires or surveys, etc. to ask people about themselves
Shortcomings of verbal reports
Cannot be used with infants, those who cannot read or understand speech, etc.
Results may reflect age differences in understanding
Responses may be socially desirable
Verbal reports
-Use interviews, written questionnaires or surveys, etc. to ask people about themselves
-Usually ask the same questions in precisely the same order of everyone so that the responses of different individuals can be directly compared
Shortcomings of verbal reports
-Measures typically cannot be used with infants, young children, cognitively impaired elders, or other individuals who cannot read or understand speech well. -Informant surveys, questionnaires, or interviews are often used in these situations instead.
-Individuals of different ages may not understand questions in the same way, and age differences in responses may reflect age differences in comprehension or interpretation rather than age differences in the quality of interest to the researcher.
-Respondents may try to present themselves (or those they are providing information about) in a positive or socially desirable light.

28. Data Collection Methods – Behavioral Observations
Naturalistic observations
Observing people in their natural surroundings and in everyday life
Used to study infants and children who lack verbal skills
Limitations of naturalistic observations
Cannot be used for rare or infrequent behaviors
Difficult to determine cause and effect
Presence of observer can influence the behavior that is being observed

29. Data Collection Methods – Behavioral Observations
Observations can be structured
Achieve more control over the conditions of observation by creating tasks or conditions related to the behavior of interest
Limitations of structured observations
Research participants may not behave naturally in the structured situation
Conclusions drawn from structured situations may not generalize to natural settings

30. Data Collection Methods - Physiological Measurements
Example: Functional magnetic resonance imaging (fMRI) measures an increase in blood flow to an area of the brain that occurs when the area is active
Advantages of physiological measurements
Hard to fake
Useful in study of nonverbal infants
Limitations of physiological measurements
Not always clear what is being assessed

31. Learning Objectives
What are the essential features of the case study method of testing hypotheses?
What sorts of information can be gathered from this type of study?
What are its advantages and limitations?

32. Methods for Testing Hypotheses – Case Study
An in-depth examination of an individual or small number of individuals
Advantages of the case study method
Can provide rich information about complex or rare aspects of development
Can be a good source of hypotheses for future larger-scale studies
Limitations of the case study method
Conclusions cannot be generalized
Case study
-An in-depth examination of an individual or small number of individuals
-Typically carried out by compiling and analyzing information from a variety of sources, such as observations, tests, and interviews
Advantages of the case study method
-Can provide rich information about the complexities of an individual’s development and the influences on it
-Particularly useful in studying people with rare conditions and disorders, when it is simply not possible to assemble a large sample of people to study (used to to examine the effects of being deprived of human contact early in life)
-Can be a good source of hypotheses for future larger-scale studies
Limitations of the case study method
-Conclusions cannot be generalized to other individuals
-Inferences about the individual’s development are speculative.

33. Learning Objectives
What are the essential features of the experimental method for testing hypotheses?
What sorts of information can be gathered from this type of study?
What are its advantages and limitations?

34. Methods for Testing Hypotheses – The Experimental Method
The investigator manipulates or alters some aspect of the environment to determine how this affects the behavior of the sample of individuals who are being studied
The goal is to see whether the different treatments (independent variable) have differing effects on the behavior expected to be affected (dependent variable)

35. Methods for Testing Hypotheses – The Experimental Method
Three critical features of true experiments
Random assignment of individuals to treatment conditions
Manipulation of independent variable
Experimental control
All factors other than the independent variable are controlled or held constant so they can’t contribute to the differences among the treatment groups

36. Methods for Testing Hypotheses – The Experimental Method
Advantages of the experimental method
Can establish cause and effect
Manipulation of the independent variable causes a change in the dependent variable
Limitations of the experimental method
Findings of laboratory experiments don’t always hold true in the real world
Principles of ethics limit the use of experiments to study human development

37. Methods for Testing Hypotheses – The Experimental Method
Quasi-experiment
An experiment-like study that evaluates the effects of different treatments but does not randomly assign individuals to treatment groups

38. Learning Objectives
What are the important features of the correlational method of testing hypotheses?
What sorts of information can be gathered from this type of study?
What are its limitations and advantages?

39. Methods for Testing Hypotheses -The Correlational Method
Determines if two or more variables are related in a systematic fashion
The strength of the relationship is expressed by the calculation of a correlation coefficient
An index of the extent to which one variable is systematically related to another variable
Can range from +1.0 to –1.0
Correlational method
-Determines if two or more variables are related in a systematic fashion
-The strength of the relationship is expressed by the calculation of a correlation coefficient
--An index of the extent to which one variable is systematically related to another variable
--Can range from +1.0 to –1.0
--Symbolized as r
--A positive correlation is obtained when both variables increase or both variables decrease
--A negative correlation is obtained when one variable increases and the other variable decreases
--A correlation of r = or r=-.90 indicates a stronger, more predictable positive relationship than a smaller correlation such as r = or r=-.30.
-A correlation of 0.00 would be obtained if there was no relationship between the two variables.
-Interpretations of correlations
-- The direction of the cause–effect relationship is reversed
--The association between the two variables is caused by some third variable

40. Caption: Plots of hypothetical correlations

41. Methods for Testing Hypotheses - The Correlational Method
Limitations of the correlational method
Cannot establish a causal relationship between one variable and another
Value of correlational method
Can be used when it is unethical to manipulate people’s experiences in an experiment
Allows an examination of multiple factors that combine to influence development

43. Methods for Testing Hypotheses – Meta-Analysis
Meta-analysis examines multiple studies that address the same question and synthesizes the results to produce overall conclusions
When results of multiple studies converge

44. Learning Objectives
What are the characteristics of cross-sectional, longitudinal, and sequential research designs?
What are the advantages and disadvantages of the cross-sectional and longitudinal designs?
How does the sequential design resolve the weaknesses of these designs?

45. Developmental Research Designs
Specialized research designs to study how people change and remain the same as they age
Cross-sectional designs
Longitudinal designs
Sequential designs

46. Developmental Research Designs – Cross-Sectional Designs
Compares the performances of people of different age groups or cohorts
Cohort – group of individuals born at the same time
Provides information about age differences
Age effects – relationship between age and a particular aspect of development
Cohort effects – effects of being born a member of a cohort or a generation in a historical context
Cross-sectional designs
-The performances of people of different age groups or cohorts are compared
--Cohort – group of individuals born at the same time
-Provides information about age differences
--Age effects –the relationship between age (a rough proxy for changes brought about by nature and nurture) and a particular aspect of development
--Cohort effects – effects of being born a member of a cohort or a generation in a historical context
Age effects and cohort effects are confounded, or entangled.

47. Developmental Research Designs – Cross-Sectional Designs
Limitations of cross-sectional designs
Age effects and cohort effects are confounded, or entangled
Do not reveal how people change with age
Advantages of cross-sectional designs
Quick and easy to conduct
Can yield valid conclusions about age effects if the cohorts studied are likely to have had similar experiences

48. Developmental Research Designs – Longitudinal Designs
Trace changes in individuals as they age
Limitations of longitudinal designs
Age effects and time of measurement effects are confounded
Costly and time-consuming
Measurement methods may become obsolete
Participants are lost
Effects of repeated testing
Longitudinal designs
Traces changes in individuals as they age
Limitations of longitudinal designs
Age effects and time of measurement effects are confounded.
Costly and time-consuming
Measurement methods may become obsolete
Participants are lost
Effects of repeated testing

49. Caption: Cross-sectional and longitudinal studies of development from age 30 to age 70

50. Developmental Research Designs – Sequential Designs
Combine the cross-sectional and the longitudinal approach and improve on both
Can reveal age effects
Can reveal cohort effects
Can reveal time of measurement effects
Sequential designs
Combine the cross-sectional and the longitudinal approach and improve on both
-Can reveal age effects
--Age-related trends that are truly developmental in nature and reflect how most people, regardless of cohort, can be expected to change over time.
Can reveal cohort effects
--Age trends that differ from cohort to cohort – how each generation is affected by its distinct growing-up experiences
Can reveal time of measurement effects
--The effects of historical events and trends occurring when the data are collected (for example, effects of an economic recession, a traumatic event like 9/11, advances in health care, or technological advances such as the introduction of the internet).
--Time of measurement effects are not unique to a particular cohort; they can affect anyone alive at the time.
which (age effects); (2) which (cohort effects); and (3) which (time of measurement effects).

52. Learning Objectives
What special challenges do developmental scientists face?
How can scientists conduct culturally sensitive research?
How do scientists protect the rights of research participants?

53. Challenges in Developmental Studies
Conducting culturally sensitive research
Study samples of developing people from variety of ecological settings
SES is particularly important
Study different cultural and subcultural groups
Keep ethnocentrism from influencing one’s research
Belief that one’s own group and its culture are superior

54. Challenges in Developmental Studies
Protecting the rights of research participants
Research ethics
Standards of conduct that protect research participants from psychological or physical harm
Informed consent
Debriefing
Protection from harm
Confidentiality
Protecting the rights of research participants
Research ethics
Standards of conduct that protect research participants from psychological or physical harm
Informed consent
--Researchers generally should inform potential participants of all aspects of the research that might affect their decision to participate so that they can make a voluntary decision based on full knowledge of what the research involves
Debriefing
---When deception has been necessary, researchers must eventually explain the true purpose of the study.
Protection from harm
--Researchers are bound not to harm research participants either physically or psychologically and must try to anticipate and prepare to deal with the consequences if harm occurs.
Confidentiality
--Researchers also have an ethical responsibility to keep confidential the information they collect.