HUMAN GROWTH AND DEVELOPMENTWINTER 2011-2012Melissa Scholten, M.A.

Chapter 1 Main points:

1. How should we think about development?2. What is the science of Life-Span

Development?3. How is development studied?4. What special challenges do

developmental scientists face?

1.1 How should we think about development?

A. Defining DevelopmentB. Conceptualizing the LifespanC. Framing the Nature/Nurture IssueD. Grasping the Ecology of Development

Defining Development

Development involves systematic continuities and changes from conception to death in three domains Physical development- growth of body, physiological change Cognitive development- changes to perception, language,

learning, and memory Psychological development- changes in personality, emotions

Growth- physical changes from conception to maturity Biological aging- deterioration of organisms Aging- positive and negative changes in maturing

organism Development of change involves both gains and losses

Conceptualizing the Lifespan Periods of lifespan: prenatal, infancy, preschool, middle

school, adolescence, early adulthood, middle adulthood, late adulthood

Age grade (age stratum)- status, roles, privileges, and responsibilities based on one’s age group

Legal definitions of age boundaries (e.g. adolescence and adulthood) vary by state

Culture impacts the recognized periods of the lifespan Eskimo simply distinguish between boy/girl and man/woman !Kung define old in terms of functioning; not age

A rite of passage is a ritual marking passage from one status to another Jewish bar or bat mitzvah Hispanic-American girl quinceanera at age 15

Conceptualizing the Lifespan Age norms- expectations based on age

Social clock- sense of timing for life transitions “Off time” (socially age inappropriate) events

have more negative impact Subcultural differences exist in age grades, age

norms, and social clocks Society is diverse with respect to race, ethnicity,

or socioeconomic status Individuals from lower- income families tend to

reach adulthood milestones earlier than those from middle- and upper- class families

Conceptualizing the Lifespan Meaning of childhood, adolescence, and adulthood

change with historic period In Western society, during the 17th century, children

came to be viewed as distinct from adults In medieval times, children were expected to grow up

as fast as possible Adolescence was recognized as a separate period in the

late 19th and early 20th centuries The need for an educated workforce and compulsory

schooling helped to lead to adolescence being viewed as a distinct period of life

Emerging adulthood is the time from age 18-29 Middle age emerged as a distinctive state of life in the

20th century (Exploration Box on emerging adulthood)

Conceptualizing the Lifespan Meaning of childhood, adolescence, and adulthood change

with historic period Some characterize middle age as a time of crisis, but it tends to be

a time of good health, peak cognitive function, and high satisfaction

Old age also became a unique time period in the 20th century In the past, relatively few individuals lived to old age, in part

because so many people died in infancy The average life expectancy (average number of years a newborn

is expected to live) is 81 for a white female, 77 for a black female, 76 for a white male, and 70 for a black male

Racial differences in life expectancy have been declining while differences based on socioeconomic status have been widening

While today’s elderly are healthier than in the past, many do have chronic diseases and disabilities and require support

Development must be viewed in historical, cultural, & subcultural context

Framing the Nature/Nurture Issue

The two sides of the debate Maturation (nature)- biological unfolding of plan

contained in genes (heredity, material from parents) Genetically influenced maturation guide us through many

of the same changes at about the same time Individual heredity endowment makes each person unique

Environment (nurture)- external physical and social conditions, stimuli, and events The nurture side- emphasizes learning (relatively

permanent changes from experiential influences) Development is due to interplay between nature and

nurture Both social (e.g. patrilineal cultures) and genetic factors both

influence levels of aggression

Grasping the Ecology of Development Bronfenbrenner’s bioecological model Stresses how biology and environment interact to produce

development Four environmental systems influence and are influenced by the

developing person Microsystem- immediate physical and social environment individual

interacts with face-to-face, involves reciprocal influence Mesosystem- linkages between two or more microsystems Exosystem- linkages involving social settings that individuals do not

directly experience (e.g. parent’s work day) but still influence behavior Macrosystem- larger culture (shared understanding and way of life of a

people) in which other systems are embedded Chronosystem- people and environments occur in particular time

frame and unfold in a particular pattern Models suggest that study of development will not be easy

Influence of factors like person, context, time, and processes difficult to separate

1.2 What is the Science of Lifespan Human Development?

Goals of Study Early Beginnings The Modern Lifespan Perspective

Goals of Study Goals of Study Description of human development Normal (typical) development Individual differences Explanation of human development

Why humans develop as they do Why some humans develop differently

Optimization of human development How can humans be helped to develop in a positive direction

(i.e. how can capacities be enhanced?)? Applied research on optimizing development should be based

on evidence-based practices (i.e. grounded in research and demonstrated to be effective)

Early Beginnings

Baby biographies Late 19th century scholars who observed and recorded the development of

their own children. Charles Darwin perhaps the most influential baby biographer

Darwin believed that infants share characteristics with nonhuman ancestors Darwin’s evolutionary perspective influences early theories of development

(Exploration Box on Darwin’s baby biography on the development of anger in his own son).

Methodology poor Biographers emphasized different aspects of development Observers not objective Observed only a single child

G. Stanley Hall Cited as founder of developmental psychology

First President of American Psychological Association Collected data on the “content of children’s minds” Wrote Adolescence (1904) in which that time of life was viewed as one of “storm and

stress” Book led to modern inaccurate notion of teenagers as emotionally unstable Wrote Senescence (1922), which was an analysis of how society treats (mistreats)

older members

The Modern Perspective Gerontology- study of aging and old age Lifespan perspective- focus on infancy through old age Key text themes

Development is a lifelong process Development is multidirectional (different aspects of

functioning have different trajectories of change) Development involves both gain and loss Life-long plasticity in human development

Plasticity- capacity to change to positive and negative experiences Plasticity continues into later life Neuroplasticity- brain’s capacity to change in response to

environmental experiences throughout the lifespan Physical exercise and mental stimulation can change

neurochemistry, create a new connections among neurons (even in the aging brain)

The Modern Perspective Development is shaped by its historical/cultural

context Great Depression impacted parental behavior and the

development of children and adolescents As societies change, developmental experiences change

(e.g. modern children hold more individualistic as opposed to communal values)

Development is multiply influenced (biology and experience) Now talk of developmental science rather than

developmental psychology Understanding development requires multiple disciplines

(e.g., biology, history, economics)

1.3 How is Development Studied? The Scientific Method Sample Selection Data Collection The Case Study, Experimental, and

Correlational Methods Developmental Research Designs

The Scientific Method

Scientific method- an attitude of systemic observation Believe the data Helps to weed out flawed ideas

Theory- set of concepts and propositions intended to describe and explain some experience

Hypotheses- predictions generated to test theory Good theories should be

Internally consistent (i.e. not generate contradictory hypotheses)

Falsifiable- (can be proven wrong) Supported by data- (i.e. have predictions confirmed by

research results)

Sample Selection

Research sample- group being studied Population- larger defined group from

which sample is drawn Random sample- a portion of the

population to be studied Means of drawing random sample from

population increases confidence in the representative nature of the sample and makes generalization possible

Data Collection Three major methods of collection are verbal reports,

behavioral observation, and physiological measures Verbal reports

Often standardized interview, questionnaires, or tests Cannot be used on infants, those who cannot read Age differences in ability to comprehend questions may occur Respondents may falsely present themselves in positive manner

Behavioral observations Naturalistic observation- behaviors observed in everyday life

Greatest advantage is that techniques study everyday life Three limitations: some behaviors occur infrequently to observe;

difficult to pinpoint cause; presence of observer may influence behavior Structured observation- researcher creates conditions to elicit a

behavior Can study behaviors rare neutral settings Concern about ability to general to natural settings

Data Collection Physiological measures

Assess physiological responses (e.g. hormone levels, heart rate)

Functional magnetic resonance imaging (fMRI)- brain-scanning technique using magnetic forces and measuring blood flow Can determine which part of brain involved in cognitive

activity Difficult to fake Sometimes unclear as to what is being assessed Multiple approaches used to study behavior (Exploration

Box on the three approaches to studying anger and aggression)

The Case Study, Experimental, and Correlational Methods

The case study In-depth examination of an individual (or

small group) Multiple sources of information (e.g. ,

observation, interview, testing) Useful in studying people with rare

conditions Can be a good source of hypotheses Conclusions cannot be generalized

The Case Study, Experimental, and Correlational Methods

The experimental method (Friedrich and Stein study on television shows and violence used as an example) Independent variable- manipulated by experimenter (Friedrich and Stein,

type of television show watch). Dependent variable- behavior affected by independent variable (Friedrich

and Stein- aggressive behavior) Freidrich and Stein results: children who were already relatively aggressive and

watched more violent television became more aggressive Three critical features of any true experiment

Random assignment to experimental conditions ensures groups similar to each other

Manipulation of independent variable needed to establish cause Experimental control- hold factors constant

Experiments: strength Can be used to determine cause

Experiments: limitations Do not hold true in real world

Ethical concerns (i.e. cannot conduct experiments on certain issues) Quasi-experiment- nonrandom assignment to treatment groups

The correlational method Correlational coefficient assesses extent that individuals’

scores on one variable are systematically related to scores on another Huesmann and colleagues correlational study on television

viewing and aggression Involves calculation of correlational coefficient

Correlational coefficient (r ) score (extent to which scores on one variable are associated with scores on another variable) with ranges from +1.0 to -1.0

High positive (+) correlation indicates the variables vary together in same direction (e.g., +0.9)

High negative (-) correlation indicates the variables vary together in opposite direction (e.g. -0.9)

Correlation near 0 indicates no relationship between variables

The Case Study, Experimental, and Correlational Methods

The correlational method Alternative explanation to positive correlation between

aggression and watching violent television (i.e. violent television causes aggression) Direction of causality may be reversed (e.g. being aggressive

may cause one to watch violent television) Third variable may cause observed association (e.g. peer

rejection causing violence and more violent television viewing) Ambiguity means that a correlation cannot be used to establish

cause Numerous studies with convergent findings best way to

establish cause/effect relationships Meta-analysis- study in which results from multiple studies

is synthesized Meta-analysis results indicate that watching violent programs is

related to roughhousing and more serious violent displays

The Case Study, Experimental, and Correlational Methods

Developmental Research Designs

Cross-sectional designs Cross-sectional designs study different age groups (cohorts)

measured at same time Cohort is a group of individuals born at the same time (either the same

year or within a span of years) Cross-sectional design- provides information about age

differences Age and cohort effects and limitations to cross-sectional

designs Age effect- relationships between age and a particular aspect of

development Cohort effect- effect of being born in one particular historical context Age and cohort effects are confounded and entangled (Exploration Box on

cohort effects and Baby Boomers) Cross-sectional designs observe an individual at only one point so they do

not measure development of the individual Advantages of cross-sectional designs

Quick and easy

Longitudinal design- studies same group (cohort) measured repeatedly Longitudinal design provides information on age changes

versus age differences and the direction or path of change Limitations of longitudinal designs

Time of measurement effects- historical events and trends’ effects on development

In longitudinal designs, time of measurement effects and age effects are confounded

Unsure if change is due to aging or the result of sociocultural effects Method is costly and time-consuming Measure become dated Loss of participants leads to smaller, less representative sample Participants can be affected by repeated testing

Although both cross-sectional and longitudinal designs have weaknesses, they are both valuable research tools

Developmental Research Designs

Sequential design- the best of both worlds Sequential designs combine cross-sectional

and longitudinal approaches Advantages of sequential designs

Can identify age-related trends regardless of cohort

Can identify cohort effects Can identify time of measurement effects

Limitations of sequential design Method extremely costly and complex

Developmental Research Designs

What Special Challenges Do Developmental Scientists Face? Conducting Culturally Sensitive Research Protect the Rights of Research

Participants

Conducting Culturally Sensitive Research

Ecological setting can influence development Must consider socioeconomic status (SES) status in

society that includes occupational prestige, education, and income Growing up in poverty or affluence will influence development

Must study individuals from different subcultures and cultures

Researcher must keep own cultural values from biasing perceptions Ethonocentrism- belief that own group and culture are

superior may creep into designs, procedures, and measures Researchers may judge minority children and adults labeled

as “deviant” versus “different: Cannot assume that all members of a culture or subculture

are alike psychologically

Protect the Rights of Research Participants

Research Ethics- standards of research conduct that researchers are ethically bound to honor Study reviewed in Exploration Box 1.3 addressed

several ethical issues Ethical issues often arise in developmental research

Ethical guidelines established by different groups American Psychological Association and Society for

Research in Child Development guidelines Human-subjects review committees (Institutional

Review Boards)

Investigator’s ethical responsibilities Weigh potential benefit and potential risk Respect rights of participants by

Allowing participant to make informed and uncoerced decision about taking part in the study

Debriefing after completion of the study Offering protection from harm Treating information as confidential

Informed consent Informed about all aspects of research that might affect

participation Those studying “vulnerable” populations must obtain informed

consent from participant and someone who can decide on their behalf

Age (young children= lack of language, old age= possible dementia)

Protect the Rights of Research Participants

Investigator’s ethical responsibilities Debriefing

Tell participants about purpose of study in advance In cases where knowledge of the study would impact response,

debriefing may occur after the study Protection from harm

Researcher may not harm participant physically or psychologically

If harm likely, then another way of answering the question should be explored

If participant is harmed, researcher must take steps to undo harm Confidentiality

Keep collected information confidential Medical records now particularly well protected Participants must give explicit permission to have information

about them be shared

Protect the Rights of Research Participants