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Chapter Two:. Theories of Development. Developmental theory —systematic statement of principles and generalizations that provides a coherent framework for studying development. What Theories Do. What Theories Do, cont. Theories

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Chapter two

Chapter Two:

Theories of Development


What theories do

Developmental theory—systematic statement of principles and generalizations that provides a coherent framework for studying development

What Theories Do


What theories do cont

What Theories Do, cont.

  • Theories

    • form basis for hypotheses that can be tested by research studies

      • formulating right question is more difficult that finding right answers

    • generate discoveries

    • offer insight and guidance by providing coherent view


What theories do cont1

What Theories Do, cont.

  • Different Types

    • grand theories—comprehensive, traditional theories

      • originated in psychology

    • minitheories—theories that focus on specific area of development

      • originated more in sociology through study of social groups and family structures

    • emergent theories—new, comprehensive groupings of minitheories

      • multidisciplinary approach includes historic events and genetic discoveries


Grand theories

Grand Theories

Grand Theories—powerful framework for interpreting and understanding change and development that applies to all individuals in all contexts, across all contents


Psychoanalytic theory

Psychoanalytic theory interprets human development in terms of motives and drives

Psychoanalytic Theory


Freud s ideas

Freud’s Ideas

Sigmund Freud

Three stages of development in first six years

oral, anal, phallic

in early childhood, latency and then adolescence, genital

each stage includes potential conflicts

how a person experiences and resolves conflicts determines personality and patterns of behavior


Erikson s ideas

Erikson’s Ideas

Erik Erikson, a follower of Freud, proposed 8 developmental stages, each characterized by a developmental crisis

trust vs. mistrust

autonomy vs. shame

initiative vs. guilt

industry vs. inferiority

identity vs. role diffusion

intimacy vs. isolation

generativity vs. stagnation

integrity vs. despair


Behaviorism

Behaviorism is built on laws of behavior and processes by which behavior is learned

focus: ways we learn specific behaviors that can be described, analyzed, and predicted with scientific accuracy

Behaviorism


Laws of behavior

Conditioning—any process in which behavior is learned

Classical conditioning—Ivan Pavlov

process by which a neutral stimulus become associated with a meaningful stimulus

stimulus and response (respondent conditioning)

Operant conditioning—B. F. Skinner

process by which a response is gradually learned via reinforcement or punishment

also called instrumental conditioning

Laws of Behavior


Social learning

Social Learning

Extension of learning theory that includes modeling which involves people observing behavior and patterning their own after it

Modeling

process in which people observe, then copy behavior

Alfred Bandura—most likely to occur if model is admired or observer is inexperienced

self-efficacy motivates people to change themselves and their contexts


Cognitive theory

Focuses on the structure and development of thought processes, which shape perceptions, attitudes, and actions.

Jean Piaget’s 4 Stages

sensorimotor

pre-operational

concrete operational

formal operational

Cognitive Theory


Cognitive theory cont

Cognitive Theory, cont.

  • Cognitive equilibrium—state of mental balance

  • Cognitive adaptation—assimilation, accommodation of ideas


Emergent theories

Emergent theories arise from several accumulated minitheories and may be the new systematic and comprehensive theories of the future

Emergent Theories


Sociocultural theory

Sociocultural Theory

Seeks to explain growth of individual knowledge, development, and competencies in terms of guidance, support, and structure supplied by the society

human development is the result of dynamic interaction of the developing persons and their surrounding culture


Guided participation

Guided participation—tutor engages learner in joint activities, providing instruction and direct involvement in learning

Apprenticeship in thinking—mentor provides instruction and support needed by novice

Guided Participation


The zone of proximal development

Zone of proximal development—range of skills learner can perform with assistance but not independently

learner is drawn into learning by teacher

Cultural variations: Basic principles are universal, but skills, challenges, and opportunities vary from culture to culture, depending on the values and structures of the culture’s society

The Zone of Proximal Development


Epigenetic theory

Epigenetic Theory

Emphasizes the interaction between genes and the environment—the newest developmental theory

stresses that we have powerful instincts and abilities that arise from our biological heritage. Timing and pace of certain developmental changes are genetically guided

performism—everything is set in advance by genes and then is gradually manifested in the course of maturation


With on and around the genes

Genetic refers to the entire genome that makes up the particular genes that cause each person to be unique

each human has a genetic foundation that is unique

epigenetic theory acknowledges the powerful instincts and abilities that arise from our biological heritage

With, On, and Around the Genes


With on and around the genes cont

With, On, and Around the Genes, cont.

  • Epi = with, around, before, after, on, or near = surrounding factors

    • epigenetic—surrounding factors that affect expression of genetic instructions

    • some surrounding factors may be stress factors; others may be facilitating factors

  • Genetic-environmental Interactions

    • genes never function alone


Genetic adaptation

Adaptation of the Genes

selective adaptation means that genes for the traits that are most useful will become more frequent, thus making survival of species more likely

Genetic Adaptation


What theories can contribute

What Theories Can Contribute

Psychoanalytic theory has made us aware of importance of early childhood experiences

Behaviorism has shown effect of immediate environment on learning

Cognitive theory helps us understand how intellectual process and thinking affect actions


What theories can contribute cont

What Theories Can Contribute, cont.

  • Sociocultural theory has reminded us that development is embedded in a rich and multifaceted context

  • Epigenetic theory emphasizes interactions between inherited forces and immediate contexts


Other theories

Other Theories

  • Brief Solution Focused

  • Narrative

  • Art

  • Play

  • PsychoDrama

  • Object-Relations

  • Jungian

  • Transactional Analysis

  • 12 - step

  • Social Learning

  • Biblio-therapy


What theories can contribute cont1

What Theories Can Contribute, cont.

  • Eclectic perspective

    • approach taken by most developmentalists in which they apply aspects of each of the various theories rather than staying with just one

  • “Integrated” is better


Eclectic verses integrated

Eclectic verses Integrated

  • Eclectic picks from multiple sources without common thread:


Integration

Integration

  • Integration picks from theories with purpose and with commonality


Level of concepts

Level of Concepts


The nature nurture controversy

The Nature-Nurture Controversy

Is it heredity or environment that shapes us?

How much is a result of any given characteristics, behavior or pattern of development is a result of genes and how much is a result of experiences

Policy and practice: nature/nurture theories are implicit in many public policies


Theoretical perspectives on hyperactivity and homosexuality

AD/HD and homosexuality—How and to what extent are nature and nurture involved in each case?

Evidence from AD/HD research that it can come from either

Theoretical Perspectives on Hyperactivity and Homosexuality


Theoretical perspectives on hyperactivity and homosexuality cont

Theoretical Perspectives on Hyperactivity and Homosexuality, cont.

  • Earlier assumptions about homosexuality: more nurture than nature. As hypotheses tested, nurture was revealed as less crucial

    • sexual orientation may be a matter of nature

    • sexual expression may be a matter of cultural attitude (nurture) but not sexual orientation

    • evidence supporting nature as main factor (e.g., affect of genetic linkage, prenatal hormones)


Theoretical perspectives on hyperactivity and homosexuality cont1

Theoretical Perspectives on Hyperactivity and Homosexuality, cont.

  • Ideology often adds to complexity and polarization of opinions on many subjects when nature and nurture are considered

  • Important to separate assumptions from facts

    • done via research and testing of hypotheses


Chapter three

Chapter Three:

Heredity and Environment


The genetic code

The Genetic Code

Development that is dynamic, ongoing, interactional, and unique; just four chemicals are the basic building blocks of the genetic code


What genes are

What Genes Are

  • Genes are made up of DNA—the complex protein code of genetic information

  • DNA directs the form and function of each body cell as it develops


What genes are cont

What Genes Are, cont.

  • Each molecule of DNA is called a chromosome

  • Chromosomes contain instructions to make all the proteins a living being needs

  • The complete packet of instructions is called a genome

  • Each person has 23 sets of chromosomes, or 46 chromosomes

  • The human genome contains 30,000 genes


The beginnings of human life

The Beginnings of Human Life

  • Gamete—reproductive cell that directs process by which genetic information combined and transmitted

  • Father gametes—sperm

  • Mother gametes—ovum


Zygote and genotype

Zygote and Genotype

  • Male and female gametes fuse and become a zygote

  • Zygote begins process of duplication and division

    • two reproductive cells

  • Genotype—the genetic information from the 46 chromosomes

    • set at human conception and endures through life


Sex determination and sex ratio

Sex Determination and Sex Ratio

  • Of 22 out of 23 pairs of human chromosome, the matching chromosomes are very closely matched

    • but not identical

      • some genes come in slight, normal variations called alleles

  • The 23rd pair is different

    • in females, it is designated XX

    • in males, it is designated XY


Sex determination and sex ratio cont

Sex Determination and Sex Ratio, cont.

  • Females always contribute one X

  • Males will have 1/2 of the sperm contributing an X and the other half contributing a Y

  • Critical factor in determining the sex of a zygote is which sperm reaches the ovum first


Sex determination and sex ratio cont1

Sex Determination and Sex Ratio, cont.

  • Other factors include

    • rarely, male sperm may only carry either X or Y

    • sometimes a woman’s uterus either unusually alkaline or acid, giving either an X or Y sperm an advantage

    • in a stressful pregnancy XY embryos are more likely to be expelled than are XX embryos in a spontaneous abortion, or miscarriage

    • current sex ratio in United States is 52 males to 48 females


Multiple zygotes

Multiple Zygotes

Monozygotic twins—identical twins (or quadruplets) originate from one zygote

share identical instructions

possibility of cloning

1/3 of twins monozygotic


Multiple zygotes cont

Multiple Zygotes, cont.

  • Dizygotic twins—from two separate zygotes

    • Dizygotic births occur once in every 60 births, and occur as frequently as 1 in 6 pregnancies, but usually only 1 twin develops past embryo stage


Multiple zygotes cont1

Multiple Zygotes, cont.

  • Dizygotic twins

    • women in late 30’s are three times more likely to have dizygotic twins

      • as menopause approaches, ovulation becomes irregular with some cycles producing no ovas and others producing multiple ovas

    • share no more genes than other offspring (about 50 percent)

      • 50 percent of the time one twin is male


Duplication division and differentiation

The zygote contains a complete set of instructions to create a person

Complex instructions on duplication, cell division, and differentiation

Duplication, Division, and Differentiation


Duplication and division

Duplication and Division

Zygote begins duplication and division within hours after conception

the 23 pairs of chromosomes duplicate, forming two complete sets of the genetic code for that person (zygote)

these two pair sets move toward the opposite sides of the zygote and the single cell in the zygote splits down the middle

the zygote’s outer membrane surrounds two cells, each containing a complete set of the original genetic code

these two cells then duplicate and divide to become four, then eight, and so on


Duplication and division cont

Duplication and Division, cont.

  • by birth, your original zygote has duplicated and divided into 10 trillion cells . . . by adulthood, it’s 100 trillion cells

  • Every cell carries an exact copy of the complete genetic instructions inherited by the one-celled zygote


Differentiation

Differentiation

Not just any cell found in the zygote can become a person

At the 8-cell stage a third process, differentiation, occurs

Cells begin to specialize

they take different forms

they reproduce at different rates, depending on where in the growing mass they are located


Differentiation cont

Differentiation, cont.

  • Certain genes affect differentiation by switching other genes on and others off so that the other genes produce the right proteins at the right times—on-off switching mechanisms

  • Genotype—the genetic potential


Gene gene interactions

Gene - Gene Interactions

Multifactoral traits—inherited traits produced by interaction of genes and environment

Polygenetic traits—inherited traits produced by gene interaction

These are affected by on-off switching mechanisms, additive genes, and dominant-recessive genes


Additive genes

Additive Genes

Additive genes—one of a number of genes affecting a specific trait

each additive gene contributes to the trait

skin color and height are determined by them

every additive gene has some impact on a person’s phenotype

when genes interact this way, all the involved genes contribute fairly equally


Dominant and recessive genes

Nonadditive genes—phenotype shows one gene more influential than other genes

This is also referred to as the dominant-recessive pattern

gene showing the most influence is referred to as dominant

gene showing the least influence is referred to as recessive

Dominant and Recessive Genes


Dominant and recessive genes cont

Dominant and Recessive Genes, cont.

  • X-linked genes—located on X chromosome

    • if recessive gene is X-linked, that it is on the X chromosome is critical

    • males have only one X chromosome; females have 2 X chromosomes

      • Whatever recessive genes a male inherits on his X chromosome cannot be counterbalanced or dominated by alleles on a second X, so any recessive genes on X will be expressed

    • Explains why males have more X-linked disorders (ex. color blindness, many allergies, several diseases, some learning disabilities)


More complications

Genes direct the creation of 20 amino acids that produce thousands of proteins forming the body’s structure and directing biochemical functions

proteins of each body cell are continually affected by other proteins, nutrients, and toxins that influence the cell functioning

More Complications


More complications cont

More Complications, cont.

  • genetic imprinting—tendency of certain genes to be expressed differently when inherited from mother than from father (tagging)

    • some of the genes which influence height, insulin production, and several forms of mental retardation affect a child differently depending on which parent they came from


Genetic diversity

Every person is unique

Genetic Diversity


Mechanisms of genetic diversity

Since each gamete contains only 23 chromosomes, why is every conception genetically unique?

8 million chromosomally different ova x 8 million of the same = 64 trillion different possibilities of children from each couple

Mechanisms of Genetic Diversity


Health benefits of genetic diversity

Genetic diversity safeguards human health

Minute differences can affect the ability to stave off certain diseases

Genetic diversity maintains the species

Health Benefits of Genetic Diversity


From genotype to phenotype

From Genotype to Phenotype

Every psychological characteristic is genetically influenced

Every psychological characteristic and personal trait is affected by the environment


From genotype to phenotype cont

From Genotype to Phenotype, cont.

  • Genotype—genetic potential

  • Phenotype—the actual appearance of an indivudal--combination of genetic potential and expression

    • we are all carriers of the unexpressed genes

      • we can pass them along through the sperm or ova


Behavior genetics

Behavior Genetics

Behavior genetics—study of effects of genes on behavior

personality patterns, psychological disorders, and intellectual abilities


Senility caused by alzheimer s disease

Most common and feared type of senility is Alzheimer’s disease

amyloid B protein accumulates in the brain, leading to dysfunction and destruction of brain cells and disruption of the mind

Can be genetic—but only when “early-onset”

Senility Caused by Alzheimer’s Disease


Senility caused by alzheimer s disease cont

Senility Caused by Alzheimer’s Disease, cont.

  • If “late-onset,” may be a combination of genes and environment

    • other predictors may include hypertension, diabetes, high cholesterol, diet, exercise, not smoking, weight control, mental alertness, and physical health


Alcoholism

Alcoholism

Inherited biochemistry makes some people highly susceptible to alcohol addiction

addictive pull can be overpowering, or weak, or something in the middle

may explain ethnic variations


Alcoholism cont

Alcoholism, cont.

Not simply a biochemical reaction—it is psychological and physical, and biological; thus alcoholism is polygenetic, with alcoholics inheriting a combination of biochemistry-affecting and temperament-affecting genes

Culture counts too(whether alcohol is present in environment)


Chromosomal and genetic abnormalities

We now give attention to these because we can recognize

disruptions of normal development

origins of genetic and chromosomal abnormalities

misinformation and prejudice add to problems of people with these abnormalities

Chromosomal and Genetic Abnormalities


Chromosomal abnormalities

A gamete with more than or less than 23 chromosomes creates a zygote with chromosomal abnormalities

most likely variable that creates chromosomal abnormalities is mother’s age (over 35)

father’s age (over 40) also a variable

Chromosomal Abnormalities


Chromosomal abnormalities cont

Most zygotes with chromosomal abnormalities never come to term

spontaneous abortion occurs in about one-half of all fetus with chromosomal abnormalities

Chromosomal Abnormalities, cont.


Down syndrome

Three chromosomes at gene #21 (trisomy-21)

Syndrome—a cluster of distinct characteristics that occur together in a given disorder

Down Syndrome


Abnormalities of the 23rd pair

Location of sex chromosome

Kleinfelters syndrome—XXY

seemingly normal child has delayed puberty

Fragile X syndrome

hanging on by a thread (mutated gene)

intensifies from generation to generation

Page 78

Abnormalities of the 23rd Pair


Genetic testing and genetic counseling

Individuals with a parent, sibling, or child with a serious genetic condition known to be dominant or recessive

Couples with history of early spontaneous abortions, stillbirths, or infertility

Couples from the same ethnic group or subgroup—especially if closely related

Women over 35 and men over 40

Genetic Testing and Genetic Counseling


The process of genetic counseling

Counselor constructs couples’ family history

charts patterns of health and illness over generations

Some tests provide information before conception

The Process of Genetic Counseling


The process of genetic counseling cont

The Process of Genetic Counseling, cont.

  • Other tests are prenatal- page 83

    • alpha-fetoprotein assay

    • ultrasound (AKA sonogram)

    • amniocentesis

    • chorionic villi sampling

    • pre-implantation testing (used in in vitro fertilization)

    • gamete selection; ova/and or sperm are screened to select ones free of particular problems


A basis for decision

Many want to know ahead of time

Some do not

There is a more knowledge of what is to come—or not

A Basis for Decision


Alternatives

Alternatives

If both partners are carriers of a serious condition or are at high risk because of age or family characteristics, they may turn to

in-vitro fertilization (IVF)

gamete intrafallopian transfer (GIFT)

zygote intrafallopian transfer (ZIF)

artificial insemination donor (AID)

postponement of pregnancy until promising treatments are further developed


Chapter four

Chapter Four

Prenatal Development and Birth


From zygote to newborn

From Zygote to Newborn

  • Germinal period—first 14 days

  • Embryonic period—3rd through 8th weeks

  • Fetal period—9th week through birth


Process of conception

Process of Conception


Germinal the first 14 days

Germinal: The First 14 Days

  • Zygote divides and keep dividing (at least though 3rd doubling they are the same)

  • At this stage (8 cells) differentiation begins

    • early “stem” cells take on distinct characteristics

    • they gravitate to locations, foreshadowing the type of cells they will become


Germinal the first 14 days cont

Germinal: The First 14 Days, cont.

  • At about a week after conception the multiplying cells separate into two masses

    • outer layer forms a shell (later the placenta) and the inner cells from a nucleus (later the embryo)

    • first task of out cells to achieve implantation— embed themselves into the nuturant environment of the uterus

  • 60% of all natural conceptions fail to implant; 70% of in vitro procedures fail to implant


Embryo from the third to the eighth week

Embryo: From the Third to the Eighth Week

  • First sign of human structure: thin line down the middle (22 days) that becomes the neural tube, which eventually forms the central nervous system, including brain and spinal column

    • fourth week

      • head begins to take shape

      • heart begins with a miniscule blood vessel that begins to pulsate


Embryo from the third to the eighth week cont

Embryo: From the Third to the Eighth Week, cont.

  • fifth week

    • arm and leg buds appear

    • tail-like appendage extends from the spine

  • eighth week

    • embryo weighs 1 gram and is 1 inch long

    • head more rounded; face formed

    • all basic organs and body parts (but for sex) present

  • 20% of all embryos spontaneously abort now


Fetus from the ninth week until birth

Fetus: From the Ninth Week Until Birth

  • Called a fetus from 9th week on


Third month

Third Month

  • Sex organs take shape (Y cell sends signal to male sex organs; for females, no signal occurs)

    • genital organs fully shaped by 12th week

  • All body parts present

  • Fetus can move every part of body

  • Fetus weighs 3 ounces and is 3 inches long


Middle three months preparing to survive

Middle Three Months: Preparing to Survive

  • Heartbeat stronger

  • Digestive and excretory systems develop more fully

  • Impressive brain growth (6X in size and responsive)

    • new neurons develop (neurogenesis)

    • synapses—connections between neurons (synaptogenesis)


Middle three months preparing to survive cont

Middle Three Months: Preparing to Survive, cont.

  • Age of viability—age at which preterm baby can possibly survive (22 weeks)

    • 26 weeks survival rate about 50%

      • brain maturation critical to viability

      • weight critical to viability

    • 28 weeks survival rate about 95%


Fetal brain maturation

Fetal Brain Maturation


Final three months viability to full term

Final Three Months— Viability to Full Term

  • Maturation of the respiratory and cardiovascular systems

    • critical difference

  • Gains weight—4.5 lbs. in last 10 weeks


Risk reduction

Risk Reduction

  • Despite complexity, most babies are born healthy

  • Most hazards are avoidable

  • Teratology—study of birth defects

    • Teratogens (ter-at-o-gens)—broad range of substances that can cause environmental insults that may cause prenatal abnormalities or later learning abilities


Determining risk

Determining Risk

  • Risk analysis—weighing of factors that affect likelihood of teratogen causing harm


Timing of exposure

Timing of Exposure

  • Critical period—in prenatal development, the time when a particular organ or other body part is most susceptible to teratogenic damage

    • entire embryonic period is critical


Amount of exposure

Amount of Exposure

  • Dose and/or frequency

  • Threshold effect—teratogen relatively harmless until exposure reaches a certain level


Amount of exposure cont

Amount of Exposure, cont.

  • Interaction effect—risk of harm increases if exposure to teratogen occurs at the same time as exposure to another teratogen or risk


Genetic vulnerability

Genetic Vulnerability

  • Genetic susceptibilities: product of genes combined with stress

  • Folic-acid deficiency may cause neural- tube defects

    • occurs most commonly in certain ethnic groups and less often in others

  • Males are more genetically vulnerable


Specific teratogens

Specific Teratogens

  • No way to predict risk on an individual basis

  • Research has shown possible effects of most common and damaging teratogens

  • AIDS and alcohol extremely damaging

    • pregnant women with AIDS transmit it to their newborns; high doses of alcohol cause FAS; alcohol + drug use increase risk to developing organism


Low birthweight

Low Birthweight

Low Birthweight (LBW)

less than 5 1/2 lbs.

grows too slowly or weighs less than normal

more common than 10 years ago

second most common cause of neonatal death

Preterm

birth occurs 3 or more weeks before standard 38 weeks


Low birthweight cont

Small for Gestational Age (SGA)

maternal illness

maternal behavior

cigarette smoking (25% of SGA births)

maternal malnutrition

poorly nourished before and during pregnancy

underweight, undereating, and smoking tend to occur together

Low Birthweight, cont.


Low birthweight cont1

Factors that affect normal prenatal growth

quality of medical care, education, social support, and cultural practices

Low Birthweight, cont.


The birth process

The Birth Process

Hormones in mother’s brain signals process

Contractions begin: strong and regular at 10 minutes apart

average labor for first births is 8 hours


The newborn s first minutes

Assessment—Apgar scale

five factors, 2 points each

heart rate

breathing

color

muscle tone

reflexes

score of 7 or better: normal

score under 7: needs help breathing

score under 4: needs urgent critical care

The Newborn’s First Minutes


Variations

Variations

Parents Reaction

preparation for birth, physical and emotional support, position and size of fetus, and practices of mother’s culture

Medical Attention

birth in every developed nation has medical attention

22% of births in U.S. are cesarean section

removal of fetus via incisions in mother’s abdomen and uterus

is medical intervention always necessary?


Birth complications

Birth Complications

Cerebral Palsy—brain damage causing difficulties in muscle control, possibly affecting speech or other body movements

Anoxia—lack of oxygen that, if prolonged, can cause brain damage or death


First intensive care then home

First Intensive Care . . . Then Home

At the Hospital

many hospitals provide regular massage and soothing stimulation; ideally, parents share in caregiving

At Home

complications, e.g., minor medical crises

cognitive difficulties may emerge, but high-risk infants can develop normally


Mothers fathers and a good start

Strong family support (familia)

Fathers play a crucial role

may help wives abstain from drugs or alcohol

can reduce maternal stress

Parental alliance—commitment by both parents to cooperate in raising child

helps alleviate postpartum depression

Mothers, Fathers and a Good Start


Mothers fathers and a good start cont

Parent-infant bond—strong, loving connection that forms as parents hold, examine, and feed their newborn

immediate contact not needed for this to occur

Mothers, Fathers and a Good Start, cont.


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