Developmental Psychology
Infancy and Childhood
Key Debates in Developmental Psychology
• Continuity vs. Stages.
• Stability vs. Change.
• Nature vs. Nurture.
Nature vs. Nurture
Heredity vs. Environment
Nature Versus Nurture
While going through
this unit it should
always be in the back
of your head…
Are you who you are
because of:
• The way you were
born - Nature.
• The way you were
raised - Nurture.
The Nature Argument
(is sometimes compelling)
This guy will never be….
This guy!!!
Why does Brad Pitt look the way he does?
Genes: Our Biological Units of Heredity
Genes: Their Location and Composition
In the nucleus of most cells we have 46 chromosomes …
Except… sperm and eggs,
which have 23.
Prenatal Development
• Conception begins with
the drop of an egg and
the release of about
200 million sperm.
• The sperm seeks out
the egg and attempts to
penetrate the eggs
• Once the sperm penetrates the egg - we have
a fertilized egg called…
The Zygote
The first stage of prenatal
development. Lasts about
14 days and consists of
rapid cell division.
• Less than half of all zygotes
survive the first two weeks.
• About 10 days after conception,
the zygote will attach itself to
the uterine wall.
• Cells begin to differentiate
(or specialize). This process is
directed by our genes.
After two weeks, the zygote
develops into an… Embryo
• Lasts about 6 weeks.
• Heart begins to beat
and the organs begin
to develop.
• By nine weeks we have a…
• By about the 6th month,
the stomach and other
organs have formed
enough to survive outside
of mother.
• At this time the baby can
hear (and recognize)
sounds and respond to
Teratogens: harmful agents to the
prenatal environment.
Fetal Alcohol Syndrome
• Physical and cognitive
abnormalities in children
caused by a pregnant
women’s heavy drinking.
• Severe cases include
facial disproportions and
cognitive abnormalities.
How do brain and motor skills develop?
Good News
• While in the womb, you
produce almost ¼ million
brain cells per minute.
Bad News
• That is basically all you
are ever going to develop.
The Newborn
• Within an hour a newborn
will turn its head to watch a
picture of a human face.
• They will turn their heads
towards human voices.
• Taste preference toward
sugar and mother’s milk.
• Inborn automatic
• Rooting (turning head
toward touch)
• Sucking
• Grasping
• Moro
• Babinski
• A child’s characteristic
emotional excitability is
evident at a very young age.
• Like shyness or being outgoing.
• Tends to be stable over time.
Brain Development in Newborns
• Cells in the brain
begin to work more
efficiently - forming
more complex neural
• Automatic, orderly,
sequential process of
physical and mental
• To a certain extent we
all maturate similarly,
but the time can vary
depending on the person.
Motor Development
• Sequence is the same - but once again
timing varies.
• First we learn to roll over, then sit up
unsupported, crawl, walk etc…
• Walking - in US 25% learn by 11 months, 50%
within a week of 1st birthday, 90% by 15 months.
• Varies by culture - if the culture emphasizes
walking then babies can walk at younger ages
• But identical twins tend to learn to walk at nearly
the same time (NATURE).
Toilet Training
• The baby needs the
physical maturation before
toilet training can take
• They can’t do it if they
can’t control those muscles.
More Developmental Patterns
• Growth Cycles - patterns of
development in which some areas
develop more rapidly and some
more slowly. (Girls have more
orderly and stable growth
• Critical Periods - specific time
after birth that is the only time
when a particular skill can begin
to develop (ex. Languages).
• Development within a species is
typically orderly and specific.
Developmental Psychology
• Studies physical, cognitive and
social changes throughout life.
• Jean Piaget (famous child
• Kids think and learn
differently than adults.
• Cognition – mental activities
associated with thinking.
• Children view the
world through
schemas (as do adults
for the most part).
• Schemas (concepts or
mental frameworks)
are ways we interpret
the world around us.
• It is basically what
you picture in your
head when you think
of anything.
Right now in your head,
picture a model.
These 3
probably fit
into your
(schema) of a
But does this one?
If I teach a 3 year
old that an animal
with 4 legs and a
tail is a dog….
• Incorporating new
experiences into
existing schemas.
What schema would you assimilate
this into?
Or this?
he call
• Adapting
current schemas
to incorporate
new information.
If I tell someone from the mid-west to picture their
schema of N.Y. they may talk about the bad areas.
But if I showed them other areas of N.Y., they would be forced to
accommodate (change) their schema to incorporate their new information.
Piaget’s 4 Stages of Cognitive Development:
1.) Sensorimotor Stage
• Experience the world through our
• Object Permanence develops
around 8 months of age.
• Birth to about 2.
2.) Preoperational Stage
• 2 – 6 or 7 years old.
• Begin to use language to represent
objects and ideas.
• Ability to think in symbols.
• Non-logical, “magical thinking”.
• Egocentrism: the inability to take
on another’s point of view
• Do NOT understand concepts of
• The idea that properties
such as mass, volume, and
number remain the same
despite changes in the
appearance of the object.
3.) Concrete Operational Stage
• 6 or 7 to about 11.
• CAN demonstrate
concept of
• Learn to think
4.) Formal Operational Stage (12 and up)
• What would the
world look like with
no light?
• Picture god.
• What are the best
strategies for
playing chess?
• Abstract reasoning.
• Able to form strategies
about things they may
not have experienced.
• Hypothesis testing.
Criticisms of Piaget
• Some say he
underestimates the
abilities of children.
• Many believe that
children do not learn in
stages but rather a
gradual continuous
growth pattern.
Social Development
• Stranger Anxiety - The fear of strangers that
infants commonly display, beginning by about 8
months of age.
• The most important social
construct an infant must
develop is  attachment
(a bond with a caregiver).
• Body contact, familiarity
and responsiveness all are
important for
Origins of Attachment
• For many animals there is a
critical period shortly
after birth when an
organism’s exposure to
certain stimuli or
experiences produce
proper development.
• Those who are deprived of
touch have trouble forming
attachment when they are
Body Contact
• Harry Harlow and his
• He showed that monkeys
needed touch or body
contact to form attachment.
• Imprinting is the process by
which certain animals form
attachments during a critical
period very early in life.
• Discovered by Konrad Lorenz.
Responsive Parenting
• Mary Ainsworth’s “Strange
Situation” study.
• Types of attachment:
1. Insecure (child is “clingy”).
2. Secure (child explores).
Parenting Patterns
• Parenting styles have been shown to have a
positive effect on a child’s self-concept.
Three types of parenting styles:
Authoritarian Parents
• Impose rules and
expect obedience.
•“Why, because I
said so!!!!”
Permissive Parents
• Parents submit to
their children’s
desires, make few
demands and use
little punishment.
Authoritative Parents
• Parents are both demanding
and responsive.
• Exert control by setting
rules, but explain the
reasoning behind the rules.
• They encourage open

Developmental Psychology - San Marcos Unified School …