2. 2
1. Introduction
2. Fact or Fiction?
3. Defining Development
4. Characteristics of Development
5. Developmental Study as a Science
6. Cautions from Science
7. Closing Thoughts
PART I: BEGINNINGS
TOPIC 1: The Science of Human Development
3. Developmental Fact or Fiction? Fiction Fact
1. The science of human development is the study of how and
why people change as they grow older, as well as how and why
they remain the same.
2. An experiment is always the best way to investigate a
developmental issue.
3. Developmental psychologists almost never base their research
on the study of one group of people over a long period of time.
4. When two variables are correlated, it means that one
caused the other.
3
PART I: Beginnings
TOPIC 1: The Science of Human Development
4. 4
What causes people to change or remain the same over time?
science of human development: Seeks to understand how and why people
of all ages and circumstances change or remain the same over time.
Science
ZouZou/Shutterstock
PART I: Beginnings
TOPIC 1: The Science of Human Development
5. What is the five-step procedure used to answer questions with empirical research
and data-based conclusions?
scientific method: A way to answer questions using
empirical research and data-based conclusions.
Develop hypothesis 2 Test hypothesis 3Curiosity 1
Draw conclusions 4 Report results 5
Raise a question
A prediction that
can be tested
Design and conduct
research; gather
empirical evidence
Support or refute
hypothesis
Share data, conclusions,
alternate explanations
5
Steps of the Scientific Method
PART I: Beginnings
TOPIC 1: The Science of Human Development
6. Is the question of nature or nurture more
about how much rather than which factor?
6
nature: Traits, capacities,
limitations each individual
inherits genetically from parents
(at conception).
nurture: All environmental
influences that affect
development (after conception).
Influences
PART I: Beginnings
TOPIC 1: The Science of Human Development
8. 8
life-span perspective: Study of
human development that takes
into account all phases of life.
How do human characteristics
change in every direction to reflect
development as multidirectional?
Multidirectional
CHARACTERISTICS OF DEVELOPMENT
PART I: Beginnings
TOPIC 1: The Science of Human Development
9. Teratogen Effects Timing
Radiation
Disrupted development of central nervous system. 8 to 15 weeks most critical
Growth and developmental retardation 3 to 8 weeks most critical
Microcephaly 3 to 38 weeks
9
Radiation
Tobacco
Alcohol
Cocaine
What happens when a potentially harmful agent — a teratogen —
is introduced at a critical period of prenatal development?
Tobacco use by mother
Limb malformation
4 to 6 weeks
Urinary tract damage
Tobacco use by father
(second-hand smoke)
Low birthweight
Late pregnancy
Reduction in weight by an average of 2 oz.
Alcohol
Fetal Alcohol Syndrome (FAS) 3 to 8 weeks most critical
Fetal Alcohol Effect
3 to 38 weeksGrowth and developmental retardation
Craniofacial dysmorphism
Cocaine
Growth retardation
3 to 8 weeks
Small head size
Premature birth
After 17 weeksProblems with placenta
Low birth weight
Attention difficulties
After birth for several years
Emotional regulation
critical period: When a
particular type of
development growth (in body
or behavior) must happen if it
is ever going to happen.
sensitive period: When a
certain type of development is
most likely, although it may
still happen later.
Connections Between Change and Time
CHARACTERISTICS OF DEVELOPMENT
PART I: Beginnings
TOPIC 1: The Science of Human Development
10. 10
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.
How does the ecological-
systems approach work?
Multicontextual
CHARACTERISTICS OF DEVELOPMENT
PART I: Beginnings
TOPIC 1: The Science of Human Development
11. 11
Cohort: A group defined by
the shared age of its
members who move through
life together, experiencing
the same historical events
and cultural shifts.
Multicontextual
CHARACTERISTICS OF DEVELOPMENT
Socioeconomic status (SES): A
person’s position in society as
determined by income,
wealth, occupation, education,
and place of residence.
PART I: Beginnings
TOPIC 1: The Science of Human Development
13. When monkey
sees, why does
monkey do?
13
Human
development
requires insights
and information
from many
Scientists in
many disciplines.
Our
understanding of
every topic
benefits from
multidisciplinary
research.
Multidisciplinary
CHARACTERISTICS OF DEVELOPMENT
PART I: Beginnings
TOPIC 1: The Science of Human Development
14. Brain
damage/
injury
The brain
is plastic,
able to
reassign
neurons
Change may
occur, some
functions
may be
restored
plasticity: Human traits can be molded (as plastic can be), yet
people maintain a certain durability of identity (as plastic does).
How plastic (moldable) are the brain and personality?
14
Plasticity
CHARACTERISTICS OF DEVELOPMENT
PART I: Beginnings
TOPIC 1: The Science of Human Development
15. 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.
How do people interact with other
people, and do so continuously
over time, each interaction
affecting the other?
15
Fancy Collection/SuperStock
Fancy Collection/SuperStock
CHARACTERISTICS OF DEVELOPMENT
PART I: Beginnings
TOPIC 1: The Science of Human Development
16. scientific observation: A method of testing
a hypothesis by unobtrusively watching and
recording participants’ behavior in a
systematic and objective manner.
Where do
scientific
observations
take place?
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Scientific Observation as a Way to Test Hypotheses
Monkey Business Images/Shutterstock
PART I: Beginnings
TOPIC 1: The Science of Human Development
17. How Do You Design an Experiment?
Many participants,
measured on many
characteristics,
including the
dependent
variable
(the behavior
being studied)
Experimental
group
Special treatment
(independent
variable)
No special
treatment
Significant change
in the dependent
variable
No change in the
variable
(predicted
outcome)
Comparison
(or control) group
(two equal
groups)
dependent variable: In an
experiment, the variable
that may change as a result of
whatever new condition or
situation the experimenter adds.
independent variable: In an
experiment, the variable that is
introduced to see what effect it has
on the dependent variable.
(Also called experimental variable.)
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The Experiment as a Way to Test Hypotheses
PART I: Beginnings
TOPIC 1: The Science of Human Development
18. SurveyInformation is
collected from a
large number of
people Acquiring valid
survey data is not
easy
Some people
lie and some
change their
minds
What happens when a survey is taken?
survey: A research method in which information is collected from a large
number of people by interviews, written questions, or some other means.
Survey
answers are
influenced by wording
and sequence of
questions
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The Survey as a Way to Test Hypotheses
Randomly
selected
Photo credit: U.S. Census Bureau, Public Information Office
PART I: Beginnings
TOPIC 1: The Science of Human Development
19. Does one of these patterns
accurately represent intelligence
as people age?
65
30
35
40
45
50
55
60
25 32 39 46 55 60 67 74 81 88
Cross-Sectional
Longitudinal
Age
T=Score
Source: Schale, 1988
cross-sectional research:
A research design that compares
groups of people who differ in
age but are similar in other
important characteristics.
longitudinal research: A
research design in which the
same individuals are followed
over time and their
development is repeatedly
assessed.
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Studying Change Over Time
PART I: Beginnings
TOPIC 1: The Science of Human Development
20. cross-sequential research: A hybrid research design in which researchers first study several
groups of people of different ages (a cross-sectional approach) and then follow those groups
over the years (a longitudinal approach). (Also called cohort-sequential research or time-
sequential research.)
How are cross-sectional and longitudinal research designs combined?
Cross-sequential
Total time: 16 years, plus double and triple analysis
2-year-olds 6-year-olds 10-year-olds 14-year-olds 18-year-olds
2-year-olds 6-year-olds 10-year-olds 14-year-olds
2-year-olds 6-year-olds 10-year-olds
[4 years later] [4 years later] [4 years later] [4 years later]
[4 years later] [4 years later] [4 years later]
[4 years later] [4 years later]
Time 1 Time 1 + 4 years Time 1 + 8 years Time 1 + 12 years Time 1 + 16 years
For cohort
effects compare
groups on the
diagonals
(same age,
different years).
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Studying Change Over Time
PART I: Beginnings
TOPIC 1: The Science of Human Development
21. correlation:
A number
between +1.0
and -1.0 that
indicates the
degree of
relationship
between two
variables,
expressed in
terms of their
likelihood that
one variable
will (or will not)
occur when the
other variable
does (or does
not).
How do variables correlate?
Quiz on Correlation
Two Variables
Positive, Negative,
or Zero Correlation?
Why?
(Third Variable)
1. Ice cream sales
and murder rate
2. Learning to read and
number of baby teeth
3. Sex of adult and
their average number
of offspring
Positive
Negative
Zero
third variable:
heat
third variable:
age
no third variable:
each child must
have a parent of
each sex
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Correlation and Causation
PART I: Beginnings
TOPIC 1: The Science of Human Development
22. 22
How do we ensure that research is done
ethically?
code of ethics: A set of moral and specific
guidelines principles that members of a
profession or group are expected to
follow.
Institutional Review Board (IRB): A group
that exists within most educational and
medical institutions whose purpose is to
ensure that research follows established
guidelines and remains ethical.
Ethics
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PART I: Beginnings
TOPIC 1: The Science of Human Development
23. How does science make the study
of human development possible?
23
Closing Thoughts
PART I: Beginnings
TOPIC 1: The Science of Human Development