Chapter 4: Developing Through the Life Span

“Developmental Psychologists”: study physical, cognitive, and social changes throughout the human life cycle. Most of their research revolves around 3 major issues:

1. Nature / Nurture: How do biology and

our environment affect development?

2. Continuity / Stages: Is development a continuous phenomenon or are their distinct changes that occur?

3. Stability / Change: Do our personality traits stay the same throughout our lifetime or do they evolve?

Prenatal Development and the Newborn:

A. Prenatal Development: Fewer than half of all “zygotes” survive past the first

2 weeks. The zygote begins as a single cell and multiplies exponentially throughout prenatal development – after 10 days the zygote attaches to the uterine wall. On the outside forms the “placenta”–on the inside forms the “embryo”. By 9 weeks, the embryo resembles a human and is known as a “fetus”.

At each prenatal stage, we are affected by genetic

and environmental factors – the placenta transfers nutrients and oxygen while screening out potentially harmful substances. Unfortunately, “teratogens” can sometimes make it through the placenta and affect the fetus (AIDS, smokers, “FAS”). Many researchers also believe that a woman’s psychological state during pregnancy can affect her fetus (+ or –).

B. The Newborn: Amazingly, newborns come equipped

with reflexes needed for survival – moving limbs to reduce pain, turning heads to breathe, and the “rooting reflex”. Feeding requires a coordinated sequence of tonguing, swallowing, and breathing.

Within days of birth, we recognize our mother’s smell and voice and we prefer sights and sounds that facilitate social responsiveness (we prefer more “human” sights and sounds). Even as newborns, we are already using our sensory equipment to learn.

INFANCY AND CHILDHOOD

I. INFANCY AND CHILDHOOD

Infancy = growing from newborn to toddler

Childhood = growing from toddler to teenager

*From infancy on, brain and mind, neural hardware and cognitive software, develop together.

Our biological development underlies our

psychological development. To understand motor and memory development, we must first understand brain development.

1. Physical Development:

A. Brain Development:

Typical newborns have around 23 billion brain cells – this is the most brain cells that they will ever have. In the beginning, the frontal lobe develops the fastest (rational planning) – the association areas of the cortex are last to develop (thinking, memory, and language). Our natural, biological (physical) development as a whole is known as “maturation”.

*Maturation sets the basic course of development; experience adjusts it.

B. Motor Development: Motor skills = physical coordination –

with minor exceptions, the sequence of motor development in humans is universal.

All babies lay roll crawl walk run

There are differences, however, in the timing of this sequence (50% of U.S. babies walk by their first birthday / 90% by 15 months). These physical developments are most linked to nature – the development of the cerebellum at the back of the brain.

C. Memory Development:

Most people cannot remember anything prior to their third birthday – “infantile amnesia”. This phenomenon occurs because we organize memories differently before/after the age of 3 or 4.

Trying to access memories of those first 4 years is like trying to read a document formatted in an earlier version of a computer program.

2. Cognitive Development:

“Cognition”: all the mental activities associated with thinking, knowing, remembering, and communicating.

The most famous cognitive psychologist is Jean Piaget (1920). Through his child intelligence research, he formulated the belief that children’s minds develop through a series of stages.

Piaget believed that the driving force behind this stage progression was our inner-need to make sense our experiences and the world around us.

Piaget thought that intellect revolved around “schemas”: frameworks that organize and interpret information. Our schemas are then adjusted through “assimilation” and “accommodation”:

“Assimilation”: interpreting new experiences in terms of

existing schemas.

“Accommodation”: adjusting old schemas to incorporate new information.

*Example: a child has a schema that 4-legged animals are dogs.

When presented with a cat, she sees the 4 legs and calls the animal a dog (Assimilation).

After, being presented with numerous 4-legged animals, the baby creates new schemas (dog, cat, horse, etc.) to incorporate new animals (Accommodation).

A. Piaget’s Stages of Cognitive Development:

1. “Sensorimotor Stage”: Birth Age 2 – begin experiencing the world through their senses and motor interactions with objects (looking, touching, grasping, mouthing). Infants typically live in the present – during this stage, they develop 2 major concepts:

“Object Permanence” – If you put an infant’s toy into a toy box, she will think it is gone for good – when playing peek-a-boo, she will think her mom has gone. By 8 months, most infants have realized that out of sight does not mean gone for good.

“Stranger Anxiety”: fear of strangers or someone looking radically different (beards, moustaches, afros, etc.) – strangers do not match existing schemas.

2. “Preoperational Stage”: 2 Age 6/7 – they can represent things with words and images, but lack logical reasoning –they are too young to perform mental operations – they lack the concept of “conservation”.

At this stage, children are “egocentric”: have difficulty taking another’s point of view – they are not intentionally selfish or inconsiderate; they simply lack the ability to take another’s viewpoint.

Throughout this stage, kids develop a “theory of mind”: ideas about their own and other’s mental states – we begin to realize that others know/don’t know things….

3. “Concrete Operational Stage”: 7 Age 11 – can think logically about concrete events (actual stimuli they can see/touch) – they have acquired the concept of conservation and can perform mathematical transformations (4 +2 = 6, what is 6-2? – with no hesitation).

4. “Formal Operational Stage”: 12 Adulthood – reasoning expands from concrete (actual experience) to abstract thinking – they can think hypothetically and deduce consequences (if this, then that).

*Piaget believed that these stages occurred one

after another (with clear breaks / no overlap). Today, most psychologists believe that the stages or intertwined – one stage begins to develop before the previous stage has ended.

3. Social Development:

A. Attachment: “Attachment”: an emotional tie with another person, is a

powerful survival impulse that keeps infants close to their caregivers. For years, people believed that attachment occurred because caregivers provided nourishment; this all changed with the research of Harry and Margaret Harlow and their study of monkeys.

See “Body Contact” pg. 155-156. Contact is the key to attachment; another is familiarity. In

many animals, attachment based on familiarity occurs during a “critical period”: an optimal period shortly after birth when certain events must take place to facilitate proper development. This is why after most deliveries, parents in the U.S. are left alone with the child for 30 minutes – 1 hour. Animals “imprint”, but children become attached to what they’ve known.

B. Attachment Differences: Placed in a strange situation, a slight majority of

kids display “secure attachment”: in mother’s presence they play comfortably and explore their environment – when the mother leaves they are distressed, but seek contact with her when she returns.

Other infants display “insecure attachment”: in

mother’s presence they are less likely to explore and may even cling to mother – when mother leaves they cry loudly and often remain upset or indifferent when the mother returns.

These attachment styles are often explained

through parenting – sensitive, responsive parents = secure attachment, while insensitive, unresponsive parents = insecure attachment. Other researchers explain attachment styles through infant temperament.

Erik Erikson explained attachment through the idea of “basic trust”: a sense that the world is predictable and reliable – he said that basic trust was a direct result of parenting.

Although the debate continues on the exact reasons for varying attachments, most agree that our early attachments form the foundation for our adult relationships.

**Deprivation of attachment, or neglectful/abusive environments, can have profound impacts on social development and adulthood well-being.

See Daycare and Attachment pg. 160-161.

C. Self-Concept: Infancy’s major social development is

attachment – childhood’s major social development is positive sense of self.

By the end of childhood (12), most children have developed a “self-concept”: a sense of your own identity and personal worth.

School-age children describe themselves in terms of gender, group memberships, psychological traits, and compare themselves to other children.

D. Child-Rearing: Obviously, parenting is associated with attachment in infancy and self-concept in

childhood. Researchers have developed 3 major types of parenting styles: 1. “Authoritarian”: parents impose strict rules and expect obedience with little or

no explanation (“too hard”) – kids usually have lower self-esteem and social skills.

2. “Permissive”: parents submit to their children’s desires, make few demands, and

use little punishment (“too soft”) – kids usually more immature and aggressive. 3. “Authoritative”: parents are both demanding and responsive – they set rules

and enforce them, but also explain reasons to their children and encourage open discussion about rules/punishments (“just right”) – kids usually have high self-esteem, self-reliance, and social competence.

*The association between parenting styles and certain childhood outcomes is

correlational – CORRELATION DOES NOT = CAUSATION! Can you think of a nature and nurture reason why this correlation might exist???

ADOLESCENCE

II. ADOLESCENCE:

“Adolescence”: life between childhood and adulthood, begins with the physical beginnings of sexual maturity and ends with the social achievement of independent adult status – it is often referred to as a period of “storm and stress”.

*This period is often marked by rewarding friendships, heightened idealism, and a growing sense of life’s exciting possibilities.

1. Physical Development:

Adolescence begins with “puberty”: the period of sexual maturation during which a person becomes capable of reproducing. Puberty results from a surge of hormones that triggers a two-year period of rapid physical development – it usually starts in girls around 11 and boys around 13.

During puberty, we experience changes in our “primary sex characteristics”: reproductive organs and external genitalia – we also develop “secondary sex characteristics”: non-reproductive traits of males and females (breasts and hips in girls / deeper voices and facial hair in boys).

The timing of puberty: psychological effects on boys/girls?

Our brains are also beginning a major change during adolescence – after puberty, brain cells begin to slow the amount of new connections made and selective “pruning” of unused neurons and connections begins.

2. Cognitive Development:

Adolescents’ developing ability to reason gives them a new level of social awareness and moral judgment – they think about their own thinking, other’s thinking, and what others are thinking about them.

A. Reasoning: During the early teen years, reasoning is

often self-focused – adolescents may think that their private experiences are unique and that no one can understand them (especially parents). Gradually, they move to Piaget’s “formal operations” in which they are capable of abstract logic (if this, then that).

The Runaway Train:

*Remember that moral thinking is a lot different from moral

action – talk is cheap if action does not follow.

B. Morality:

A crucial task of childhood and adolescence is learning right from wrong and developing character . Lawrence Kohlberg (1981) worked in the realm of “moral reasoning”: the thinking that occurs as we consider right and wrong. He concluded that we pass through 3 basic levels of moral thinking:

1. Preconventional Morality: based on self-interest – they obey to avoid punishment or gain concrete rewards (typically age 9 and under)

2. Conventional Morality: based on caring for others, upholding laws/social rules simply because “they are the laws and rules” (early adolescence).

3. Postconventional Morality: based on people’s rights or basic ethical principles.

Not surprisingly, as our thinking matures, our behavior also becomes less selfish and more caring.

3. Social Development:

Erik Erikson (1963) viewed life as a series of crises that need resolution – at different ages we experience different dilemmas – See Table 4.2 (pg. 170). In adolescence, Erikson believed our major crisis is a search for identity.

A. Identity:

“Identity”: one’s sense of self – is often a result of trial and error. Adolescents in Western culture often try out different selves in different situations (in school, out of school, at home). When selves overlap???

Sometimes we form our identities based on our parents’ – sometimes we do the complete opposite.

According to Erikson, once a strong sense of identity is developed, we can move onto the young adulthood stage of “intimacy”: the ability to form truly close relationships.

4. Emerging Adulthood:

In the Western world, adolescence corresponds to the teen years. Today, kids reach biological maturity earlier, but seem to reach adulthood (independence) later – as a result, the period of adolescence is a longer time than ever before.

Some psychologists have dubbed the period from age 18 to the mid-twenties “emerging adulthood” – a time when individuals are no longer adolescents, but haven’t reached full adulthood either.

*Rites of Passage in the U.S. and abroad???

ADULTHOOD

III. Adulthood

It is hard to generalize about adulthood’s stages because there is such a large age range, variation of individuals,

biological, and environmental factors.

1. Physical Development:

Physical abilities (muscular strength, reaction time, sensory keenness, etc.) reach their peak in our mid-twenties and then decline gradually.

A. Changes in Middle Adulthood:

While it may seem that vigor decreases as we get older, it has more to do with a person’s health and exercise habits than age. How is age viewed in the United States? Around the world???

For women, age means a gradual decline in fertility – typically, the older a woman gets, the harder it is to conceive (and birth) a child “menopause “) *Many women find it to be a relief and report feeling better than ever after menopause occurs.

There is no male equivalent to menopause.

B. Changes Later in Life: See Quiz on pg. 177 In 2004, the average life expectancy was 67 (world-

wide) – some developed countries have average life expectancies over 80. Since people are living longer and longer, the elderly population is becoming larger and larger. Can you see any problems that could result from this fact?

Men are more prone to dying – this constant from conception, to birth, to infancy, and continues throughout adulthood. Women outlive men by 4 years worldwide (5-6 years in the U.S.). By age 100, women outnumber men 5 to 1.

Eventually, all bodies age – cells stop reproducing, frailty sets in, and it becomes much more vulnerable to outside influences (weather, viruses, and injuries).

As we age, many senses begin to decline – visual sharpness, muscle strength, reaction time, hearing, smell, and stamina all diminish noticeably. There is good and bad news in regard to health: short-term vs. life-threatening.

Unfortunately, aging slows the neural processing in the brain. Older people tend to take a bit more time to react and remember – brain regions important to memory begin to atrophy during aging. Fortunately, exercise feeds the brain – “use it or lose it”.

The sad truth is that many elderly people eventually experience a mass loss of brain cells resulting in “dementia” – the worst case scenario is the onset of “Alzheimer’s disease”: disease that causes the gradual deterioration of memory, reasoning, language, and physical functioning (due to lack of Ach).

2. Cognitive Development:

One of science’s major questions is whether or not cognitive ability (memory, creativity, intelligence, etc.) parallel the typical decline of our physical abilities…

A. Aging and Memory: It has been found that people most vividly recall

recent events and events from life’s second two decades (teens and twenties). Early adulthood seems to be a peak time of learning and remembering – this may be due to the fact that many of life’s “firsts” occur at this time…

Remembering also seems to depend on the type of

information you are trying to recall – the more meaningless the information, the harder it is for older people to recall (pills, locks, time-oriented, etc.)

B. Aging and Intelligence: In 1972, David Wechsler performed an adult

intelligence test using a “cross-sectional study”: people of different ages are compared with one another. His findings revealed that older people consistently scored lower on IQ tests than younger adults.

These findings stood until Shale and Geiwitz (1982) performed their “longitudinal study”: retesting the same people over a period of years. Their findings concluded that until late life, intelligence remained stable; and on some tests, it even increased.

What are some factors that may have affected each study?

Cross-sectional = different eras, education

levels, affluence, family environment, etc.

Longitudinal = survival of the fittest (health) In the end, most researchers agree that

intelligence decrease/increase with age depends on the type performance we measure:

“Crystallized Intelligence”: accumulated

knowledge of facts, increases with age.

“Fluid Intelligence”: ability to reason speedily and abstractly, decreases with age.

3. Social Development:

Many differences between younger and older adults occur as a result of environment. The question becomes, do these normal events of adult life form a predictable sequence of life changes for everyone?

A. Adulthood’s Ages and Stages:

As people enter their forties, they transfer into middle adulthood. Most soon realize that life will soon be mostly behind them instead of ahead of them –most research suggests that there is no “midlife crisis”.

Some psychologists talk of the “social clock” (cultural timing). In western society, our social clock has been pushed back – more than ever, it is harder to predict when adults will go through these key life events – as a result, stress from not reaching these milestones is often reduced.

B. Commitments: Erikson believed that two basic elements dominate

adulthood – Intimacy (forming close relationships) and Generativity (being productive and supporting future generations).

Adult bonds of love are most satisfying when marked by a similarity of interests and values, emotional and material support, and intimate self-disclosure. In the United States, roughly 50% of all marriages end in divorce (roughly 75% re-marry).

As humans, we seek monogamy – the reason: marriage is a predictor of happiness, health, and income. Love often bears children – a blessing to some relationships and a curse to others. As with the midlife crisis, current research highly disputes the concept of “empty nest syndrome”.

C. Overall Well Being: From early adulthood to midlife, people typically

experience a strengthening sense of identity, confidence, and self esteem. Even as everything seems to be “going downhill” in later life, older people report as much happiness and satisfaction as younger people do – a stable life is often a content life.

D. Death and Dying: We will all have to cope with death at some point –

what types of death are hardest to deal with?

Everyone deals with death in their own way, it is not as cut and dry as psychologists once believed – it is easier for most to accept death if they feel as though their life has been meaningful and worthwhile.