DrMarshallpsychch9ppt

1. Lecture Slides
Chapter Nine
Lifespan
Development
By Glenn Meyer
Trinity University

2. Introduction
Developmental psychology is the study
of how people change over the lifespan.
• Focuses on psychological changes
across the entire lifespan
• Every area of psychology can be looked
at from this perspective
• Biological development
• Social development
• Cognitive/perceptual development
Critical Issues
• Can some development be described in
terms of stages?
• Are there critical periods during which the
child is maximally sensitive to
environmental issues?
• What part of development can be
described as gradually unfolding
changes?
• We need to investigate the interaction
between heredity and environment,
known as the nature–nurture issue

3. Genetic Contributions
Important Terms
Zygote — single
cell formed at
conception from
union of egg cell
and sperm cell
Chromosome — a
long, thread-like
structure composed
of twisted parallel
strands of DNA;
found in cell nucleus
Deoxyribonucleic
acid (DNA) —
double-stranded
molecule that
encodes genetic
instructions;
chemical basis of
heredity
Gene — a segment
of DNA on a
chromosome that
encodes instructions
for making a
particular protein
molecule; basic unit
of heredity
Genotype —
genetic makeup of
an individual
organism
Alleles — different
forms of a particular
gene
Sex chromosomes
— chromosomes,
designated as X or
Y, that determine
biological sex; 23rd
pair of
chromosomes in
humans
Phenotype —
observable traits or
characteristics of an
organism as
determined by
interaction of
genetics and
environmental
factors
Zygote
Click here
Chromosome
Click here
Deoxyribonucleic
acid (DNA)
Click here
Gene
Click here
Genotype
Click here
Alleles
Click here
Sex chromosomes
Click here
Phenotype
Click here

4. Chromosomes, Genes and DNA
23 pairs of human chromosomes
X and Y
chromosomes

5. Your Unique
Genotype
• Mother’s egg cell and father’s sperm cell each
contributed 23 chromosomes
• Set of 23 chromosome pairs represents your unique
genotype or genetic makeup
• Human genome contains only about 20,000 to 25,000
protein-coding genes
• Dominant genes will always be expressed if present
• Recessive genes will not be expressed unless they are
in a pair
• Most characteristics involve the interaction of multiple
genes
From Genotype to Phenotype
• Different genotypes react differently to environmental
factors
• Psychologists and scientists believe people have
genetic predispositions to develop in a particular way
• Most of the genes in each person are dormant
• Experience affects which genes are turned on (and off)
• Environment participates in sculpting the expression of
the genome
Examples:
brown
eyes, five
fingers
Examples:
blue eyes,
extra
fingers

6. Epigenetics
Study of the cellular mechanisms
that control gene expression and of
the ways that gene expression
affects health and behavior
• Gene expression can be triggered by the activity of
other genes, internal chemical changes, or by
external environmental factor
• Epigenetic “settings” determine whether a cell will
become a skin cell, a nerve cell, or a heart muscle
cell
• Suicide victims who had been abused as
children had distinct epigenetic marks in brain
tissue that were not found in suicide victims
who had not been abused as children or in
accident victims.

7. Prenatal Development
Germinal and Embryonic Periods
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

8. Embryonic Period
Risk of teratogens
• Exposure to radiation
• Toxic chemicals and metals, such as
mercury, PCBs, and lead
• Viruses and bacteria, such as German
measles (rubella), syphilis, genital
herpes, and human immunodeficiency
virus (HIV)
• Prescription painkillers and other
prescription and nonprescription drugs
• Addictive drugs, including heroin,
sedatives, cocaine, amphetamines,
and methamphetamine
• Maternal smoking and exposure to
second-hand smoke
• Alcohol — Fetal alcohol syndrome:
abnormal facial features, poor
coordination, learning disabilities,
behavior problems, and mental
retardation
• Mother’s psychological state,
unhealthy behaviors
Teratogens—any
agent that causes a
birth defect

9. Prenatal Brain Development
During peak periods of brain
development, new neurons are
being generated at the rate of
250,000 per minute.
• Brain begins as a fluid-filled
neural tube about three weeks
after conception
• The neural tube is lined with stem
cells
• Neural stem cells divide and
multiply, producing neurons and
glial cells
• Top of tube thickens into three
bulges that form the hindbrain,
midbrain, and forebrain
• Hindbrain structures are first to
develop
• Followed by midbrain structures
• Forebrain structures develop
last, eventually surrounding and
enveloping the hindbrain and
midbrain structures

10. Fetal Period
• Third and longest period of prenatal development, extending
from the ninth week until birth
• Main task: body systems grow and reach maturity in
preparation for life outside mother’s body
• Fetal brain is forming as many as 2 million synaptic
connections per second
• Connections that are used are strengthened, while
connections that remain unused are eventually pruned or
eliminated
• Fetus has distinct sleep–wake cycles and periods of activity
• During sixth month, fetus’s brain activity becomes similar to
newborn baby’s
• At birth, newborn’s brain is one-fourth the size of adult brain,
weighing less than 1 pound
• After birth, neurons grow in size and continue to develop
new dendrites and interconnections with other neurons
• Myelin forms on axons in key areas of the brain, such as
those involved in motor control

11. Development During Infancy
and Childhood
Newborn 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
• Grasping—the baby will grip your fingers
so tightly that he can be lifted upright

12. Newborn Senses • Newborn infant is
extremely nearsighted
• Image of a human face
holds the newborn’s gaze
longer than do other
images
• Optimal viewing distance
for the newborn is about
6 to 12 inches
• Newborns only 10
minutes old will turn their
heads to continue gazing
at the image of a human
face as it passes in front
of them, but they will not
visually follow other
images
• Within just hours of birth,
a newborn displays a
preference for her
mother’s voice and face
over a stranger’s

13. Physical Development Patterns
• During infancy, the brain will grow to about 75 percent of its adult
weight
• Cephalocaudal pattern — physical and motor skill development
tends to follow a “top to bottom” sequence
• Proximodistal trend — develop motor control from the center of
bodies outwards
• Basic sequence of motor skill development is universal, but the
average ages can be a little deceptive

14. Social and Personality Development
Temperamental Qualities: Babies Are Different!
Reactivity (Kagan)
Click here
Classic distinctions (Thomas and
Chase)
Click here
• Easy—adaptable, positive mood,
regular habits
• Slow to warm up—low activity,
somewhat slow to adapt, generally
withdraw from new situations
• Difficult—intense emotions,
irritable, cry frequently
• Average—unable to classify (1/3 of
all children)
• High-reactive infants react
intensely to new experiences,
strangers, and novel objects
• Low-reactive infants tend to be
calmer, uninhibited, and bolder
Influences
• Individual differences in temperament have a genetic and
biological basis
• Environmental experiences can modify a child’s basic
temperament
• Infant temperament can also be affected by cultural beliefs

15. Attachment:
Forming Emotional
Bonds
The emotional bond that forms
between the infant and caregivers,
especially parents, during the first
year of life is called attachment.
Ainsworth’s Strange
Situation
Mother-child dyads were
observed in a playroom under
four conditions:
• Initial mother-child interaction
• Mother leaves infant alone in
playroom
• Friendly stranger enters
playroom
• Mother returns and greets
child

17. Forms of Attachment
Securely attached infants
explore the room when
mother is present, become
upset and explores less
when mother is not
present, and show
pleasure when mother
returns
Insecurely attached
babies are less likely to
explore the environment,
even when their mother is
present
Avoidant attachment
a form of insecure
attachment in which the
child avoids his mother and
acts coldly to her
Anxious resistant
attachment
a form of insecure
attachment in which the
child remains close to
mother and remains
distressed despite her
attempts to comfort

18. Baby Sleeping Arrangements
• United States: Babies usually sleep in their own beds
• Mayan families and other cultures allow baby to sleep
with mother until 2 or 3 years old
• Differences because of pragmatic reasons – staying
warm?
• Reflects different cultural values of independence and
interdependence
• Should the baby be independent and self-reliant?

19. Language Development
Universal Characteristics
• By the time a child reaches
3 years of age, she will
have learned approximately
3,000 words and many
complex rules of language
• Noam Chomsky (1965):
every child is born with a
biological predisposition to
learn language—any
language
• Infants can distinguish
among the speech sounds
of all the world’s languages
• Infants lose this ability by
10–12 months of age

20. Encouraging Language Development
Mothers, Parents, or Infant-Directed Speech
Very distinct pronunciation
Simplified vocabulary
Short sentences
High pitch and exaggerated intonation
and expression
Content is restricted to topics that are
familiar to the child
Adult use of infant-directed speech seems
to be instinctive
Infants seem to prefer infant-directed
Found with deaf mothers and signing

21. • Comprehension
vocabulary (the words
she understands) is
much larger than her
production
vocabulary
• Babies produce their
first real words around
their first birthday
• Words usually refer to
concrete objects or
people that are
important to the child
• Single words and vocal
intonation stand for an
entire sentence
• Cooing
• 3 months of age
• Repeating vowel sounds, such as ahhhhh
or ooooo
• Babbling
• Consonant/vowel sounds at 5 months of
age
• ba-ba-ba-ba, de-de-de-de, or ma-ma-ma-ma
• Infants all over the world use the same sounds
when they babble, including sounds that do
not occur in the language of their parents
• At around 9 months of age, babies begin to
babble more in the sounds specific to their
language
• Babbling is biologically programmed
One-Word Stage of
Language Development
Click here
Cooing and Babbling Stage of Language
Development
Click here
• Occurs around child’s second birthday
• Use two words to construct a simple “sentence”
Examples: “Mama go.” “Where kitty?” “No potty!”
• Primarily content words—nouns, verbs, and sometimes adjectives or
adverbs
Two-Word Stage of Language Development
• Articles (a, an, the) and prepositions (such as in, under, on) are omitted.
• At 2½ years of age, most children can increase length and grammatical
complexity of sentences
Click here
• At age 3, most children have a production vocabulary of more than 3,000
words
• Acquiring about a dozen new words per day, a child may have a production
vocabulary of more than 10,000 words by school age

22. Cognitive Development
• Jean Piaget — most influential theory of cognitive
development
• Believed that children actively try to make sense of
environment rather than passively soaking up
information
• Children progress through four distinct cognitive
stages: sensorimotor, preoperational, concrete
operational, formal operational
• As a child advances to a new stage, thinking is
qualitatively different
• Develops a new understanding of world in each
progressive stage, building on understandings
acquired in the previous stage
• Child assimilates new information and
experiences, changes his way of thinking to
accommodate new knowledge

24. Sensorimotor Stage
Birth - 2 years
• Information is gained through the
senses and motor actions
• In this stage child perceives and
manipulates but does not reason
• Symbols become internalized
through language development
• Object permanence: the
understanding that objects exist
independent of one’s actions or
perceptions of them
• Before 6 months of age infants
act as if objects removed from
sight cease to exist –Can be
surprised by
disappearance/reappearance of
a face (peek-a-boo)

25. Preoperational Stage
2 - 7 years
• Emergence of symbolic thought: ability to
use words, images, and symbols to
represent the world
• Centration: tendency to focus, or center, on
only one aspect of a situation, usually a
perceptual aspect
• Egocentrism: egocentric children lack the
ability to consider events from another
person’s point of view
• Lack concept of conservation
• Two equal physical quantities remain
equal even if the appearance of one is
changed, as long as nothing is added or
subtracted
• No understanding of irreversibility
• Animism
• Artificialism

27. Concrete Operational Stage
7-12 years
• Understanding of mental operations leading to
increasingly logical thought
• Classification and categorization
• Less egocentric
• Inability to reason abstractly or hypothetically
• Understand concept of conservation
Example: When presented with two rows of
pennies, each row equally spaced, concrete
operational children understand that the number
of pennies in each row remains the same even
when the spacing between the pennies in one
row is increased.

28. Formal Operational Stage
12 years – Adulthood
• Solves complex and hypothetical
problems
• Able to think in abstract terms

29. Criticisms of Piaget’s Theory
Criticism 1
Baillargeon and her colleagues have
shown that infants as young as 2½
months of age display object
permanence.
Piaget underestimated the
cognitive abilities of infants and
young children
Click here

30. Lev Vygotsky
• Believed that cognitive
development is strongly
influenced by social and cultural
factors
• Children are able to attain higher
levels of cognitive development
through the support and
instruction that they receive from
other people
• Zone of proximal development—
what a child can do by interacting
with another person, but can’t do
alone
• Critical thinking based on
dialogue with others who
challenge ideas
• Findings suggest that Piaget’s
stages are not as universal and
culture-free as some researchers
had once believed
Researchers have found that many adults
display abstract-hypothetical thinking only
in limited areas of knowledge and that
some adults never display formal
operational thought processes at all.
Information-Processing Perspective
• Rather than distinct stages of cognitive
development (Piaget), some
developmental psychologists
emphasize this model
• Views cognitive development as a
process that is continuous over the
lifespan; studies development of basic
mental processes (attention, memory,
problem solving)
Criticism 2
Piaget underestimated the
impact of social and cultural
environment on cognitive
development
Click here
Criticism 3
Piaget overestimated degree to
which people achieve formal
operational thought processes
Click here

31. Adolescence
• Transitional stage between late
childhood and early adulthood,
during which sexual maturity is
reached
• Adolescence is the stage that
marks the transition from
childhood to adulthood

32. Physical and Sexual Development
• Puberty—stage at which an individual reaches sexual
maturity and is physically capable of sexual
reproduction
• Primary sex characteristics—sex organs directly
involved in reproduction
• Secondary sex characteristics—develop during puberty,
not directly involved in reproduction, but distinguish
male from female
• Adolescent growth spurt—period of accelerated growth
during puberty
• Menarche—female’s first menstrual period, typically
occurs around age 12 or 13
• Testicles typically begin enlarging around age 11 or 12;
girls are typically about two years ahead of boys in
terms of physical and sexual maturation

33. The Adolescent Brain
• Little evidence of “raging hormones” causing emotional
problems
• Neuronal pruning surges occur
• Prefrontal cortex is the last area to experience pruning,
which is responsible for executive cognitive functions,
such as reasoning, planning, and organizing
• Second wave of gray matter overproduction just prior
to puberty, followed by a second round of neuronal
pruning during the teenage years
• The prefrontal cortex reaches full maturity by mid-20s.
An adolescent’s occasional impulsive, risky or
immature behavior is due to a brain that has not
reached full adult maturity.

34. Genetics—girls
experience
menarche around
same age as their
mother did, closer for
identical twins than
nontwin siblings
Factors that
Affect the
Timing of
Puberty
Click here
Environment
—nutrition
and health
Body size and physical
activity
• Heavier children begin
puberty earlier
• Physically demanding
exercise delays
menarche
Quality of
family
relationship
Absence of the father in
the home environment
• Menarche comes earlier
for girls in these homes
• Boys in these homes
have accelerated
physical development

35. Effects of Early Versus Late Maturation
Girls:
• Early-maturing girls are more likely
than late-maturing girls to have
negative feelings about body image
and pubertal changes
• Embarrassed by unwanted attention
from older males
Boys
• Early maturation can be
• Higher rates of sexual risk-taking,
Girls who develop early
and boys who develop
late are most likely to
substance use, and delinquent
behavior
advantageous for boys
(popularity, athletics)
have problems
• At greater risk for unhealthy weight
• Risks include
gain later in life
depression, drug use

36. Social Development
• Parent-child relationships overall positive, but conflict
does increase during this time; this is seen as healthy as
autonomy increases
• Friends and peers become more of an influence
• Peer relationships tend to reinforce the traits and goals
that parents fostered during childhood
• Romantic relationships influence psychological and
social development in both positive and negative ways
• By age of 12, about 25 percent of adolescents report a
“special romantic relationship”
• By age 15: 50 percent; by age 18: 70 percent
• Social and cultural factors influence when, why, and how
adolescents engage in romantic and sexual behaviors

37. Identity
A person’s sense of self,
including his or her memories,
experiences, and the values
and beliefs that guide his or
her behavior.
Identity
Formation
Erikson’s Theory of
Psychosocial
Development
Erikson:
• Divided life span into
eight psychosocial
stages, each
associated with a
different drive and a
problem or crisis to
resolve
• Outcome of each stage
varies along a
continuum from positive
to negative
• Psychological research
has generally
supported Erikson’s
description of the
process of identity
formation

39. Development of Moral Reasoning
Moral reasoning
how an individual thinks about
moral decisions
Kohlberg
• Most influential theory of moral development was
proposed by Kohlberg, who concluded that there are
distinct stages of moral development.
• Kohlberg’s original belief that the development of
abstract thinking in adolescence naturally and
invariably leads people to the formation of idealistic
moral principles has not been supported
• Moral reasoning for most people seems to be captured
by Kohlberg’s first four stages
• By adulthood, the predominant form of moral
reasoning is conventional moral reasoning, reflecting
the importance of social roles and rules

41. Critiques of Kohlberg’s Theory
• Most important criticism of
Kohlberg’s theory is that
moral reasoning doesn’t
always predict moral
behavior
• Moral decisions in the real
world are often affected by
no rational processes, such
as emotional responses,
custom, or tradition
• Based on research on
males
• Based on Western
perspective of individual
rights and justice
• Doesn’t take into account
collectivist values, religious
purity, or loyalty to family

42. Gender, Culture, and Moral Reasoning
• Kohlberg’s theory based on male participants
• Kohlberg’s model based on ethic of individual rights and
justice, more common perspective for men
• Gilligan (1982) developed a model of women’s moral
development based on an ethic of care and
responsibility
• Gilligan found women tend to stress importance of
maintaining interpersonal relationships and responding
to needs of others
• Research shows that Kohlberg may be incorrect, but so
was Gilligan
• Evidence suggests that both men and women used a
mix of care and justice perspectives

43. Adult Development Development during
• Physical strength typically peaks in early adulthood:
the 20s and 30s
• By middle adulthood, roughly from the 40s to the mid-
60s, physical strength and endurance gradually
decline
• Physical and mental reaction times also begin to slow
during middle adulthood
• During late adulthood, from the mid-60s on, physical
stamina and reaction time tend to decline further and
faster
• Loss of lean muscle, increased body fat, weakened
bones, and cognitive decay
adulthood is marked by
physical changes and the
adoption of new social
roles.
Physical changes: With each decade after age 20,
the efficiency of various body organs declines.

44. Andropause in Men
Middle-aged men do
not experience an
abrupt end to their
reproductive
capability
Experience a
gradual decline in
testosterone levels
Erectile dysfunction,
reduced sexual
motivation and
function
Menopause in
Women
Signals the end of
reproductive capacity
Occurs any time from
the late 30s to the
early 50s

45. Social Development Middle adulthood
The primary psychosocial task
becomes one of generativity—
to contribute to future
generations through your
children, your career, and
other meaningful activities.
Friends and Lovers in Adulthood
• Adults typically have fewer friends than adolescents do
• Female friends tend to confide in one another
• Male friends tend to do things of mutual interest
• Young adults are marrying at a later average age
• “Traditional” family may no longer be the norm

46. The Median Age at First Marriage

47. Late Adulthood and Aging
• Life expectancy for men in
the United States is 75
years; for women it’s 80
years
• Old age as a time of poor
health, inactivity, and
decline is a myth
• Decline in mental abilities
is often because of lack of
practice or experience
• Activity theory of aging—
life satisfaction is highest
when people maintain
level of activity they had in
earlier years

48. Cognitive Changes
• Mental abilities remain relatively stable until
about the age of 60
• Most older adults maintain their previous
levels of ability
• 70s, 80s, and 90s show slight but significant
declines in memory, perceptual speed, and
fluency
• Measures of knowledge, such as vocabulary,
remained stable up to age 90
• Neurons appear to become less efficient at
communicating with one another
• Older brains compensate for decline in
processing speed by outsourcing to other
parts of the brain
• Better education and engaging in physical
and mental activities throughout older
adulthood slows declines in mental abilities

49. Social Development
• One theory: older adults gradually “disengage,” from
vocational, social, and relationship roles as they face
the prospect of their lives ending
• Activity theory of aging: life satisfaction in late
adulthood highest when maintain previous level of
activity
• Well-being in old age includes achieving what Erik
Erikson called ego integrity—the feeling that one’s life
has been meaningful
• Despair is experienced by those who are filled with
regrets or bitterness about mistakes, missed
opportunities, or bad decisions

50. Final Chapter
In general, anxiety about dying peaks in middle
adulthood, tends to decrease in late adulthood
Denial
Anger
Bargaining
Depression
Acceptance
Kübler-Ross’s
stages of dying
These stages are not
universally demonstrated

51. Parenting Styles
Authoritarian parenting style
• Demanding but unresponsive to their children’s needs or wishes
Permissive parenting styles
• Permissive-indulgent parents are responsive, warm, and
accepting of their children, but impose few rules and rarely punish
their children
• Permissive-indifferent parents are both unresponsive and
uncontrolling
Authoritative parenting style
• Warm, responsive, and involved with their children; set clear
standards for mature, age-appropriate behavior; and expect their
children to be responsive to parental demands
• This is the style that is associated with a broad range of beneficial
effects for the adolescent, such as higher grades and better
confidence

52. How to Be an Authoritative Parent:
Some Practical Suggestions
1. Let your children know that you love them.
2. Listen to your children.
3. Use induction to teach as you discipline.
4. Work with your child’s temperamental qualities.
5. Understand your child’s age-related cognitive
abilities and limitations.
6. Don’t expect perfection, and learn to go with the
flow.