Chapter 9

Chapter 9: Psychology Over the Lifespan
Prenatal Development (from Conception to Birth)
A. The role of nature and nurture
1. Life begins with the meeting of two gametes (a sperm and an egg, or ovum).
2. Each human inherits 23 pairs of chromosomes (23 from the sperm, 23 from the egg).
a. A chromosome is a strand of DNA.
b. Each gene on a chromosome is a series of “rungs on the ladder” of the DNA strand.
c. All cells in a human body contain all 23 pairs of chromosomes except sperm, which contain a Y
chromosome, and egg cells which contain an X chromosome.
3. The fertilization of an egg by a sperm creates a zygote.
a. Much of early development is determined by genetically programmed, age-related changes known
as maturation.
b. Each zygote consists of a unique combination of genes.
4. Human prenatal development is divided into three trimesters.
a. The first trimester is divided into three stages: the zygote, the embryo, and the fetus
b. The bulk of the neurons each individual possesses are in place by the end of the second trimester.
c. Almost half of all fertilized eggs contain abnormalities that can result in spontaneous abortion.
5. A fetus in the womb is active almost from the beginning of the fetal stage.
a. After about 25 weeks of gestation, the fetus is sensitive to both sound and light.
b. By 28 weeks it responds to external stimulation.
c. Between 25 and 34 weeks, it can respond to human speech.
d. There is evidence that fetuses can learn and exhibit habituation.
6. Teratogens can harm a developing fetus.
a. More than half the babies born to mothers who contract rubella will be mentally retarded.
b. There are a variety of teratogens, ranging from infectious agents, to drugs, to environmental
pollutants and radiation.
c. Stressors can also endanger the developing fetus.
7. The environment can also have positive developmental effects.
a. Prolonged prenatal exposure to violin music has been linked to more advanced development in the
first six months of life.
b. Social support can lower the possible effects of maternal stress.
B. The newborn
1. The human brain is not fully developed at birth.
While infants are physically almost helpless, they have a surprising range of abilities and
2. Sensory capacities
a. They are born sensitive to the range of women’s voices.
b. They have a relatively sensitive sense of smell.
3. Reflexes
a. Newborns possess the Moro reflex, the Babinski reflex, and other reflexes.
b. Many of these reflexes disappear after awhile.
4. Temperament
a. Newborns may demonstrate different temperaments almost immediately.
b. Early nurturing experiences, such as touching and handling, can also have impact on temperament.
II. Infancy and Childhood
A. Physical and motor development
1. There is rapid physical growth in the first two years.
a. After this, growth slows and occurs in spurts.
2. Motor control also develops in phases.
a. Generally, control progresses from the head down the trunk to the legs.
b. Control also tends to progress from the trunk outward to the hands, feet, fingers and toes.
c. The development of control has both maturational and environmental components.
B. Perceptual and cognitive development
1. Visual perception
a. Visual acuity is poor at birth, but develops with age.
Newborns can perceive overall shapes and depth by 2 or 3 months of age.
2. Auditory perception
a. This is more fully developed at an earlier age than visual perception.
3. Some aspects of perceptual development continue to develop until late adolescence.
D. Language development.
1. All normal humans learn language without needing to be taught it explicitly. This learning develops in
an orderly progression.
a. Mothers instinctively adjust their language, when talking to infants, so that their babies receive
clear messages. This is called child-directed speech, or “motherese.”
b. Infants have very sophisticated abilities to encode spoken sounds, but after about six months they
begin ignoring distinctions in sounds not used in language spoken around them.
c. Infants’ ability to discriminate and organize sounds outstrips their ability to produce them.
d. All babies, even deaf ones, begin babbling at about 6 months of age.
e. By about 1 year of age, the babbling begins to have adultlike intonation patterns.
(1) Deaf children do not develop advanced babbling, but if exposed to sign
language will develop more advanced signing skills.
Most children begin to speak when they are about a year old.
g. By the time they are 6 years old, children know approximately 10,000 words.
h. Young children know more words than they can say, at any given age.
7-month-old babies can already abstract grammarlike rules, but children do not begin to produce
simple two-word “sentences” (called telegraphic speech) until approximately 2 years of age.
Between ages 2 and 3, English-speaking children start to use sentences that follow the sequence of
k. By age 4, most children understand and can generalize grammar rules, although they often make
the overregularization error.
There is evidence of a critical period for learning rules of grammar, although not for learning
language in general. There may be sensitive periods for learning language in general.
D. Cognitive Development
1. Piaget’s Theory
a. He believed that infants begin with very simple schemas.
b. The infant uses assimilation to take integrate new stimuli, and accommodation to modify existing
c. He believed children pass through four major periods of cognitive development.
(1) The sensorimotor period (0-2 years), characterized by the development of object permanence.
(2) The preoperational period (2-7 years), characterized by egocentrism.
(3) The concrete operational period (7-11 years), characterized by the understanding of
“conservation” of and reverse mental manipulations.
(4) The formal operational period (11 years and over), characterized by reason based on abstract
logic and the ability to imagine hypotheticals.
d. Researchers have found that young children, even infants, are capable of much more than Piaget
believed, and at younger ages.
(1) Children begin to develop a theory of mind by age 6 months.
(2) They develop different theories of mind depending on their surrounding culture.
e. Researchers have also found that Piaget was generally correct in his idea that that there are
qualitative changes in children’s performance as they age.
2. The information processing approach argues that perception and cognition rely on distinct processes
that do not all mature at the same rate.
a. Research has found that some mental processes, such as short-term memory, develop more quickly
than others, such as working memory.
3. Vygotsky’s sociocultural theory
a. He focused on the role of social interactions in allowing a child to construct representations of the
world by absorbing his or her culture.
b. He argued that adult guidance, especially in learning language, is crucial to development.
c. With language, children learn to use private speech to prompt themselves to behave in certain
d. He argued that with language, children develop a variety of different ways, depending on what they
are taught as they grow up.
e. While children from different cultures do master different skills, the importance of culture and
private speech in their ability to master complex skills is unclear.
E. Social and emotional development
1. Infants quickly develop attachment to their primary caregivers.
a. “Cupboard theory” argued that this was because their caregivers feed them.
(1) Harry Harlow’s research with baby monkeys disproved this.
(2) Harlow’s research indicated an innate need in mammals for “contact comfort.”
b. Bowlby argues that children go through phases in developing attachment.
(1) Separation anxiety often characterizes the period between 6 months and 2 years.
c. Ainsworth has identified four types of attachment:
(1) Secure attachment (60-70% of American babies)
(2) Avoidant attachment (15-20% of American babies)
(3) Resistant attachment (10-15% of American babies)
(4) Disorganized/disoriented attachment (5-10% of American babies)
d. The type of early attachment an infant displays can have long-lasting effects.
F. Self-concept refers to the beliefs, desires, and attributes that define a person to herself or himself. For
young children, self-concept is linked to cognitive development.
1. Self-concept may begin to develop at birth.
2. By age three, children understand they have distinct psychological characteristics.
G. Gender identity is the belief you are male or female. Exposure to sex hormones in
the womb predispose children toward a male or female gender identity.
H. Moral development
1. Lawrence Kohlberg used moral dilemmas to assess the sophistication of children’s moral thinking.
2. Kohlberg identified three levels of moral development, each with two stages:
a. The preconventional level rests on the idea that good behaviors are rewarded and bad ones are
b. The conventional level rests on the role of rules that maintain social order and allow people to get
c. The postconventional level rests on the development of abstract principles that govern the decision
to accept or reject specific rules.
3. Males and females use different moral principles, but the differences reflect differing daily activities
rather than inherent gender differences.
4. Moral development occurs slowly, with very few people ever moving into the postconventional level.
5. People may use different types of moral reasoning depending on the situation.
III. Adolescence: the period between the appearance of sexual characteristics and the teenage years
A. Physical development
1. Adolescence begins with puberty.
a. Puberty may actually begin with hormonal changes that begin at age 6, and more dramatic physical
changes that begin at age 8.
2. Physical development during this period moves from the hands and feet to the trunk.
a. Boys develop larger shoulders relative to their hips, more muscle mass, larger lung capacity, larger
hearts, and more red blood cells.
b. Girls develop larger hips relative to their shoulders, and accumulate more fat.
(1) Girls begin their growth spurt about 2 years ahead of boys.
c. Girls typically stop growing by about age 13, and boys by about age 16.
B. Cognitive development
1. The major cognitive development is the ability to reason abstractly (formal operations).
2. Not all adolescents develop this ability.
C. Social and emotional development
1. Goethe called adolescence a period of “storm and stress.”
2. Adolescents tend to have three sorts of problems:
a. Conflicts with their parents
(1) Frequency is greatest in early adolescence; intensity is greatest during mid-adolescence
b. Strong mood swings
(1) By the mid-teens about 1/3 of adolescents are seriously depressed.
(2) Many adolescents report feeling lonely and nervous.
c. Risk taking
(1) These behaviors tend to peak in late adolescence.
3. Hormonal changes may predispose adolescents to mood swings, but situational factors actually trigger
the changes.
4. Adolescent egocentrism
a. Many adolescents constantly behave as if they are in front of an imaginary audience.
b. Many adolescents have a personal fable
(1) This can lead them to feel invulnerable and take extreme risks.
(2) This can make them feel as if no one else understands them.
c. Adolescents are still primarily influenced by parents and family in regard to basic values and goals.
IV. Adulthood and aging
A. Physical changes
1. By the early 20s, height has peaked and weight stabilizes.
2. After age 50, more dramatic physical changes begin to occur.
3. Some age-related changes are genetically programmed, others are environmentally caused.
a. Changes such as menopause are inevitable.
b. Other changes may result from obesity, lack of exercise, and malnutrition, and these are often
preventable or controllable.
4. All humans experience decline in energy and vigor as they age.
a. Most likely due to the cumulative effects of genetic errors in cell reproduction and the impact of
environmental chemicals and stressors.
B. Adult cognition and perceptions
1. Cognitive abilities remain stable through adulthood.
a. Some abilities begin to decline after age 50, but most of these declines are minor and not
b. Aging most severely affects connections among neurons, which eventually
slows people’s performance and increases the errors they make.
2. Vision begins worsening during early and middle adulthood, but can usually be corrected. Worse
problems occur in later life. Over half of people over age 65 have cataracts.
3. After age 50, people have increased difficulty hearing high-frequency sounds.
Older people also have more difficulty ignoring background sounds.
4. Taste does not decline significantly with age, but smell does, leading people to often prefer spicier
foods as they move into old age.
5. Memory often have problems with some types of memory.
Declines in acetylcholine production can affect the hippocampus.
Semantic memories and storing new episodic memories do not tend to decline.
Recalling specific episodic memories becomes more difficult.
Older people also have more problems with tasks involving working memory.
6. Intelligence
a. Genetic influences on general intelligence increase with age.
b. Longitudinal studies indicate that both crystallized and fluid intelligence are stable until between
the mid-50s and early 70s.
c. Cross-sectional studies indicate, however, that fluid intelligence may begin declining in the late
20s, whereas crystallized intelligence may increase with age until near the very end of life.
d. Aging affects specialized abilities very differently, depending on the person.
e. Practice and compensation can help many older people retain close to normal intellectual abilities
C. Social and emotional development in adulthood
1. Erikson’s theory of psychosocial development
a. Erikson argued for three stages of psychosocial development in adulthood:
(1) Young adulthood, characterized by the issue of intimacy versus isolation.
(2) Middle adulthood, characterized by the issue of generativity versus self-absorption.
(3) Late adulthood, characterized by the issue of integrity versus despair.
2. Levinson’s argued that a midlife transition often occurs in men between the ages of 40 and 45, leading
many men to have a midlife crisis.
(1) Levinson’s use of interviews to collect data has been questioned.
(2) Other researchers have not found evidence that most men experience a midlife crisis.
3. Overall, there appear to be very few changes in the dimensions of personality with aging.
4. Adult relationships
a. As people age, generally they interact with fewer people, but the interactions tend to be more
(1) They tend to interact more with relatives and less with friends.
D. Death and dying
1. The most influential theorist on the psychology of death is Elisabeth Kubler-Ross.
a. Her theory argues that people pass through five stages in dealing with their own impending deaths:
(1) Stage 1: Shock and denial
(2) Stage 2: Anger
(3) Bargaining with God and others
(4) Depression and withdrawal
(5) Acceptance
b. These stages may only apply to people dying at a relatively young age.
c. Not everyone goes through these stages.
2. Death anxiety does not increase with age, and may decrease in old age.
3. Women report fearing death more than men do.
4. There are clear cultural differences in how people view death.
5. Grief and bereavement typically follow the death of a loved one.
a. Americans tend to experience grief in three phases:
(1) Shock for about the first three weeks
(2) Emotional upheavals from three weeks to about a year
(3) Grief lessens during the second year
Grief over the death of an older person tends to be different than grief over the death of a younger