Developing Through the Life Span
Prenatal Development and the
Newborn
 Conception
 Prenatal Development
 The Competent Newborn
Developing Through the Life Span
Infancy and Childhood
 Physical Development
 Cognitive Development
 Social Development
 Thinking About Nature and Nurture
Developmental Psychology
• The study of how we change – physically,
cognitively, and socially – throughout the
life span.
Three Major Issues for
Developmental Psychology
1. Nature and nurture: How do genes interact
with the environment to influence
development?
2. Continuity and stages: What parts of
development are gradual? What parts change
abruptly in stages?
3. Stability and change: Which traits persist
through life? How do we change as we age?
Prenatal Development and the
Newborn
How, over time, did we come to be who we are?
From zygote to birth, development progresses
in an orderly, though fragile, sequence.
Conception
A single sperm cell (male) penetrates the outer
coating of the egg (female) and fuses with the
egg to form one fertilized cell.
The Fertilized Egg
• The new cell contains the genetic code
that helps make a person – the same code
will be carried by every one of that
person’s cells!
• The code is carried on chromosomes,
threadlike structures made of DNA
(deoxyribose nucleic acid), stored in each
cell’s nucleus
Heredity
• Genes are pieces of
DNA, which can be
expressed or made
inactive by environmental
events, and control the
emergence of trait
characteristics
• Heredity: Genes are
passed from parents to
offspring
Genome
Genome is the set of complete instructions for
making an organism, containing all the genes in
that organism’s chromosomes.
•Humans share 99.9% of their DNA with each
other!
•Genetic differences account for many trait
differences especially physical traits
•Traits may be influenced by many genes
especially complex ones such as personailty
Gene-Environment Interaction
• Human differences are also shaped by the
environment –external influence starting
with maternal nutrition in the womb
• Genes and environment interact.
– Example: a naturally shy child will come to
have different experiences than a very
outgoing one, leading to different behaviors
Prenatal Development
• Zygote: Conception to 2 weeks.
– Divides into 100 cells in the first week, when
cells start to differentiate.
• Embryo: 2 weeks through 8 weeks.
– Attaches to the uterine wall.
• Fetus: 9 weeks to birth.
– Internal organs start develop.
Prenatal Development
embryo at one month
fetus at two months
fetus at three months
Twins
• Identical twins
develop from a single
fertilized egg
• Fraternal twins
develop from separate
fertilized eggs
Teratogens
• Teratogen: any agent (e.g., chemical,
virus) that can reach the developing infant
during prenatal development and cause
harm.
• Example: heavy drinking during pregnancy
can cause fetal alcohol syndrome (FAS),
characterized by physical abnormalities
and lifelong mental impairment
The Competent Newborn
Infants are born with
• Example: Rooting:
reflexes – unlearned,
automatic reflex of
automatic responses to
searching for a nipple
a sensory stimulus.
when something
touches the baby’s
Responding to faces,
cheek
crying for food, rooting
reflex, and sucking.
• Failure to find
satisfaction may lead
to crying
The Competent Newborn
Offspring cries are important signals for parents
to provide nourishment. In animals and humans
such cries are quickly attended to and relieved.
The Competent Newborn
Predisposition to Faces:
• Newborns, even an hour after birth, prefer to
look at shapes that resemble faces
Newborns Differ
• Temperament: a person’s characteristic
emotional reactivity and intensity.
• One aspect of personality
• Rooted in biology.
– Identical twins have more similar personalities
(including temperament) than fraternal twins
Infancy and Childhood
 Physical Development
 Cognitive Development
 Social Development
Infancy and Childhood
Infancy
Newborn
Childhood
Toddler
Teenager
Maturation: The biological growth
processes leading to orderly changes in
behavior, independent of experience.
Example: The crawling infant matures into a
walking toddler, no matter what nurture is
provided.
Physical Development
• Brain development
• Motor development
Brain Development
• Most neurons form in the womb
• Immature wiring – networks form after birth
• Frontal lobes – seat of rational planning.
– Most rapid growth during ages 3 to 6
– Continue to develop into adolescence and beyond
• Association areas – linked with memory,
language, and learning
– Last to develop
– Mental abilities surge with development
Neural pruning
• Use it or lose it!
– Unused neural pathways get shut down
– Connections that get used become
strengthened
Experience and Brain Development
Experience and Brain Development
• Young children easily master language
• But harder to learn once adolescence is
reached
• Critical period for some skills – exposure
to some certain stimuli or experience is
required during this time for proper
development
• Also true for visual perception
Motor Development
• Universal sequence of development
– Sitting
– Crawling
– Walking
– Running
Cognitive Development
• Babies are capable of learning
– Two-month-old learned to kick leg to make a
mobile spin above his crib
– Infants in a follow up experiment recalled
which mobile could be moved this way
– Learning endured: They still recalled a month
later that their kick could move the mobile
Jean Piaget
• Believed children’s
minds develop in
stages, each with its
own style of
reasoning
• Partly involves
building schemas –
concepts or
frameworks for
organizing information
Sensorimotor Stage
• Here, babies take in the world by looking,
hearing, touching, mouthing, and grasping.
• During this stage, after six months, children
learn object permanence: that an object out of
sight still exists
[Insert Figure 3.10]
Sensorimotor Stage: Criticisms
• Object permanence unfolds gradually,
development is more continuous than
Piaget proposed
• Children are more competent than Piaget
believed – they can grasp simple physics
– Children stare longer at events which seem to
defy laws of physics
Preoperational Stage
• Ages 2 to 6 or 7
• Child learns to use language
• These children learn pretend play, by age
3 using one object to represent another.
• Cannot yet perform mental operations of
concrete logic, such as conservation
Preoperational children lack concept of
conservation
This child can’t mentally reverse the act of pouring, to see that
the amount of milk was conserved when poured into a taller
yet thinner container
Preoperational Stage
• Egocentrism: difficulty imagining another
person’s point of view
• During this stage, children develop a theory of
mind: the ability to understand that other people
have their own thoughts, reactions, feelings,
intentions, and even mistaken ideas or “false
beliefs
• Autism usually includes an impaired theory of
mind – they have difficulty reading other
people’s thoughts and feelings. (non-verbal
cues)
Concrete Operational Stage
• Between ages 6 or 7 to 11
• Children gain mental abilities to think
logically about concrete events
• Piaget believed children fully gain ability to
understand simple math and conservation
• Vygotsky described inner speech –
children talk to themselves no longer
thinking out loud
Formal Operational Stage
Around age 12, our reasoning ability expands
from concrete thinking to abstract thinking. We
can now use symbols and imagined realities to
systematically reason. Piaget called this formal
operational thinking.
More about this stage when we discuss
adolescence…
Reflecting on Piaget’s Theory
• Studies from around the world confirm that
human cognition unfolds in essentially the
sequence he described
• Today’s research see development as more
continuous, less discretely in stages
• It’s important to remember that children cannot
think logically like adults
• Children’s cognitive immaturity is adaptive: It
keeps them close to protective parents and
opportunities for learning and socialization
Social Development
Stranger anxiety is the fear of strangers that
develops at around 8 months. This is because
infants form schemas for familiar faces and
become distressed at unfamiliar ones.
Attachment: An Emotional Bond
• By 12 months, infants cling to parent when
frightened or expect separation
• Shower parent with smiles and hugs when
reunited
• This emotional bond is a powerful survival
impulse
Origins of Attachment
Harlow (1950s) showed
that infants bond with
surrogate mothers
because of bodily
contact and not because
of nourishment.
Infant monkeys used the
cloth “mother” as a
secure base for
exploring
Attachment: Separation Anxiety
Peaks
around 13
months,
then
declines
Attachment and Later
Relationships
• Attachment style may provide foundation
for adult relationships
• Erikson: secure children approach life with
a sense of basic trust – a sense that the
world is predictable and reliable
• Adult relationship styles also exhibit types
of attachment, which in turn may influence
attachment in children during parenting
Deprivation of Attachment
• What happens if children are prevented from
forming attachments?
• Insights from Romanian orphanages –
children were frightened, withdrawn, and
occasionally speechless
• Unloved children may become unloving
adults
• Abused children (and animals) may become
fearful or aggressive
• Yet many abused, neglected children are
resilient and later thrive
Parenting Styles
Practice
Description
Authoritarian
Parents impose rules and expect
obedience.
Permissive
Authoritative
Parents submit to children’s
desires, make few demands, use
little punishment.
Parents are demanding but
responsive to their children.
Parenting Styles
• Authoritative parenting correlates with
highest rates of self-esteem, self-reliance,
and social competence
• However, correlation is not causation –
other factors may lead to both the
parenting style and the other factors
• Also, parenting does not occur in a
vacuum – Culture Matters.
Culture and Child-Rearing
• Different cultures emphasize different values
in child-rearing
– “Learn to take care of yourself” vs. “Work well
with others and don’t make waves”
• There are also differences in environment
– Some households, especially in Asia and Africa,
maintain physical family closeness (family bed)
to maintain emotional closeness, others have
separate rooms to foster independence
• There is no one right way to raise children
successfully
Thinking about Nature and Nurture