Human Development
Fundamental Issues in
Developmental Psychology
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Developmental Psychology
 Basic question: What shapes the way we
change over time?
 Focus on psychological changes across the
entire life span
 Every area of psychology can be looked at
from this perspective
biological development
social development
cognitive / perceptual development
personality development
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Fundamental Issues:
Nature vs. Nurture
 What is role of heredity vs. environment in
determining psychological makeup?
Is your IQ inherited or determined by
nutrition and early environment?
Is there a ‘criminal’ gene or does poverty
lead to criminal behavior?
Is sexual orientation a choice or
genetically determined?
 These are some of our greatest societal
debates
 Mistake to pose as ‘either / or’ questions
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Fundamental Issues: Is
Development Continuous?
 Development means change - change can be
abrupt or gradual
 Two views of human development
stage theories: there are distinct phases
to intellectual and personality development
continuity: development is continuous
 These views have been applied to social,
personal and intellectual development
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Fundamental Issues in
Developmental Psychology
 Critical period - Are there periods when an
individual is particularly sensitive to certain
environmental experiences?
Are the first hours after birth critical for parentchild bonding?
Is first year critical for developing trust?
Easier to learn a language before age 10?
 Are there individual differences in stages and
critical periods?
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Developmental Research
Methods
Cross-sectional - performance of
people of different age groups is
compared
Longitudinal - performance of one
group of people is assessed
repeatedly over time
Sequential - combines cross-sectional
and longitudinal approaches in a single
study
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Physical and Psychological
Development Related
Physical development begins at
conception
Physical maturity sets limits on
psychological ability
visual system not fully functional at birth
language system not functional until much
later
Prenatal environment can have lifetime
influence on health and intellectual
ability
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Prenatal Development
Conception - when a sperm penetrates
the ovum
Zygote - a fertilized egg
Germinal period - first two weeks after
conception
Embryonic period - weeks three through
eight after conception
Fetal period - two months after
conception until birth
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Prenatal Influences on
Development
Teratogen - any agent that causes a
birth defect (e.g., drugs, radiation,
viruses)
Fetal Alcohol Syndrome (FAS)
cluster of defects occurring in infants born
to mothers that drink heavily during
pregnancy
leading cause of mental retardation
can be totally prevented by abstaining
from alcohol during pregnancy
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Infant Abilities and
Perceptions
What does an infant feel and perceive?
William James said, “booming, buzzing
confusion.” Was he right?
Is infant vision just a blur?
Is infant sound just buzzing and booming?
He was probably wrong, but infants have
limited ability to communicate, so it is
hard to tell what they experience
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Infant Abilities
Infants are born with immature visual
system
can detect movement and large objects
Other senses function well on day 1
will orient to sounds
turn away from unpleasant odors
prefer sweet to sour tastes
Born with a number of reflex behaviors
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Infant Reflexes
Rooting - turning the head and opening
the mouth in the direction of a touch
on the cheek
Sucking - sucking rhythmically in
response to oral stimulation
Babinski - fanning and curling toes
when foot is stroked
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Infant Reflexes
Moro - throwing the arms out, arching
the back and bringing the arms
together as if to hold onto something
(in response to loud noise or sudden
change in position of the head)
Grasping - curling the fingers around
an object
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Methods for Studying
Infants
Infant reflexes provide insight into
their mental life
gaze duration related to visual
perception
head turning related to auditory
attention
sucking, reaching, kicking can be
used to measure interest
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Infant Perception
 Not just a blur or a
buzz
 In first week
will recognize their
mother’s smell
will show preference
for novel stimuli
gaze at face-like
pattern rather than
similar non face-like
pattern
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Infant Perception
Infants explore their environment in
whatever way their physical
development permits
At 2-3 months will grasp object and put
in mouth to explore
At 3-4 months will manipulate object,
examine it visually, selectively attend
to novel objects or events
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Infant Perception
 A basic question is how knowledge of the
properties of physical objects arises
object permanence
objects can’t pass through other objects
dropped objects fall
 Research on infant selective attention
measure gaze duration
create physically impossible events
infants notice at 3-4 months
 Depth perception- visual cliff
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Summary
Developmental psychology concerned
with psychological change over the life
span
Issues are very broad
heredity vs. environment
stages vs. continuous change
Are there critical periods?
prenatal influences
How much ability are we born with?
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