Chapter 1: Introduction
Defining Development
The science of
human
development…
seeks to understand
how and why
people—all kinds of
people, everywhere,
of every age—change
over time.
Understanding How and Why
• Something that is empirical is based on
observations, repeated experiences,
verifiable experiments. It is not theoretical.
• The scientific method is a way to answer
questions using empirical research and
data-based conclusions.
Understanding How and Why
Five Basic Steps of the Scientific Method
• Begin with curiosity.
• Develop a hypothesis.
• Test the hypothesis.
• Draw conclusions.
• Report the results.
The Scientific Method
Often, a sixth step is needed before the
scientific community accepts conclusions.
• Replication: The repetition of a study,
using different participants.
The Nature-Nurture Debate
• Nature refers to the influence of genes
which we inherit.
• Nurture refers to environmental
influences, such as:
–
–
–
–
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health and diet of the embryo’s mother
family
school
community
society
Critical and Sensitive Periods
• A critical period is a time when certain
things must occur for normal development.
• A sensitive period is when a particular
development occurs most easily.
Observing Changes Over Time
• Dynamic-Systems Theory
A view of human development as an ongoing,
ever-changing interaction between the physical
and emotional being and between the person
and every aspect of his or her environment,
including the family and society.
The Life-Span Perspective
An approach to the study of human development that
takes into account all phases of life, not just childhood
or adulthood.
Development is Multidirectional
• Over time, human characteristics change in every
direction.
• Several major theorists describe stages of
development: Freud, Erickson, Piaget.
• Others view development as a continuous process.
The Life-Span Perspective
• Ecological-Systems Approach
The view that in the study of human
development, the person should be
considered in all the contexts and
interactions that constitute a life. (Later
renamed bioecological theory.)
The Life-Span Perspective
Development Is Multicontextual
• Historical Context- All persons born within a few
years of one another are said to be a cohort, a
group defined by the shared age of its members.
The Life-Span Perspective
Socioeconomic Context
• socioeconomic status (SES)
A person’s position in society as determined by
income, wealth, occupation, education, and
place of residence.
The Life-Span Perspective
Development Is Multicultural
• Culture - patterns of behavior passed from one
generation to the next.
• Vygotsky described the interaction between
culture and education.
The Life-Span Perspective
Development Is Multicultural
• Ethnic group - People whose ancestors were
born in the same region and who often share a
language, culture, and religion
• Race – A group of people who are regarded by
themselves or by others as distinct from other
groups on the basis of physical appearance.
The Life-Span Perspective
Development Is
Multidisciplinary
• Genetics and
neuroscience are two of
the newer disciplines in
lifespan research.
• Every trait—psychological
as well as physical—is
influenced by genes.
The Life-Span Perspective
Development Is Plastic
• Human traits can be molded, yet people
maintain a certain durability of identity (as plastic
can).
• Mirror neurons- Cells in an observer’s brain
that respond to an action performed by someone
else in the same way they would if the observer
had actually performed it.
Using the Scientific Method
Scientific Observation
• Requires the researcher to record behavior
systematically and objectively.
• May be done in a naturalistic setting such as a
home, school, or other public place.
• May be done in a laboratory.
Using the Scientific Method
• The Experiment establishes causal
relationships among variables.
– independent variable- variable that is
introduced to see what effect it has on the
dependent variable.
– dependent variable- variable that may
change as a result of whatever new condition
or situation the experimenter adds.
Using the Scientific Method
• experimental group- gets a particular
treatment (the independent variable).
• comparison group (also called a control
group), which does not get the
experimental group treatment.
Using the Scientific Method
The Survey
• Information is collected from a large number of
people.
• Acquiring valid survey data is not easy.
• Some people lie, some change their minds.
• Survey answers are influenced by the wording
and the sequence of the questions.
Studying Development over the
Life Span
Cross-sectional Research
• Groups of people of one age are compared with
people of another age.
Longitudinal Research
• Collecting data repeatedly on the same
individuals as they age.
Cross-sequential Research
• Study several groups of people of different ages
(a cross-sectional approach) and follow them
over the years (a longitudinal approach).
Using the Scientific Method
Cautions from Science
Correlation and Causation
• A correlation exists between two variables if
one variable is more (or less) likely to occur
when the other does.
– Positive correlation - both variables tend to
increase or decrease together.
– Negative correlation - one variable tends to
increase while the other decreases.
– Zero correlation - no connection is evident.
• Correlation is not causation
Cautions from Science
Quantity and Quality
• Quantitative research
Provides data that can be expressed with
numbers, such as ranks or scales.
• Qualitative research
Considers qualities instead of quantities.
-Descriptions of particular conditions and
participants’ expressed ideas are often part
of qualitative studies.
Ethics
• Each academic discipline and professional
society involved in the study of human
development has a code of ethics.
• An Institutional Review Board (IRB) ensures
that research follows established guidelines and
remains ethical.
• Participation is voluntary, confidential, and
harmless.
• Research subjects must give informed consentunderstand the research procedures and any
risks involved.