Download Lesson 1- Genetics

IX. Developmental Psychology (7–9%)
Meyers book- Chapters 3 and 4
Developmental psychology deals with the behavior of organisms from conception to death and examines
the processes that contribute to behavioral change throughout the life span. The major areas of emphasis in
the course are prenatal development, motor development, socialization, cognitive development,
adolescence, and adulthood.
AP students in psychology should be able to do the following:
• Discuss the interaction of nature and nurture (including cultural variations) in the determination of
behavior.
• Explain the process of conception and gestation, including factors that influence successful fetal
development (e.g., nutrition, illness, substance abuse).
• Discuss maturation of motor skills.
• Describe the influence of temperament and other social factors on attachment and appropriate
socialization.
• Explain the maturation of cognitive abilities (e.g., Piaget’s stages, information processing).
• Compare and contrast models of moral development (e.g., Kohlberg, Gilligan).
• Discuss maturational challenges in adolescence, including related family conflicts.
• Characterize the development of decisions related to intimacy as people mature.
• Predict the physical and cognitive changes that emerge as people age, including steps that can be taken to
maximize function.
• Describe how sex and gender infl uence socialization and other aspects of development.
• Identify key contributors in developmental psychology (e.g., Mary Ainsworth, Albert Bandura, Diana
Baumrind, Erik Erikson, Sigmund Freud, Carol Gilligan, Harry Harlow, Lawrence Kohlberg, Konrad
Lorenz, Jean Piaget, Lev Vygotsky).
Lesson 1- Genetics
Behavioral Genetics
The nature-nurture controversy deals with the extent to which heredity and the
environment influence our behavior. Behavioral genetics studies the role played by
inheritance in mental ability, temperament, emotional stability, etc.
I. Transmission of hereditary characteristics is achieved by biological processes
(including gametogenesis, fertilization, embryonic development and protein synthesis).
A. Chromosomes carry information stored in genes to new cells during reproduction
1. Human body cells have a constant number of chromosomes = 46 in
normal cells.
2. Cells of the ovaries and testes produce eggs (ova) and sperms
(spermatozoa) which normally have 23 chromosomes each by a process
(gametogenesis) that involves the disjunction of pairs of chromosomes
which have genes for the same traits.
3. Of the 23 pairs of chromosomes in human body cells, 22 pairs are non-sex
chromosomes (autosomes) and one pair constitutes the sex chromosomes.
a. A female has 22 pairs of autosomes and two X sex chromosomes.
Thus normal eggs have 22 chromosomes plus an X
b. A male has 22 pairs of autosomes and one X and one Y sex
chromosome. Thus normal sperms have 22 autosomes + either an
X or a Y
4. At fertilization the chromosomes from the egg and sperm recombine to
form a zygote (fertilized egg) with 46 chromosomes that will develop into
a new individual.
5. The sex of the new individual is determined by the sperm that fertilizes the
egg.
a. If the sperm carries an X chromosome, the baby will be a female
b. If the sperm carries a Y chromosome, the baby will be a male.
c. Zygotes develop into females without the presence of a Y
chromosome.
6. The new individual gets approximately half his/her hereditary material
from the mother and half from the father, one chromosome from each pair.
7. Genes, carried by chromosomes, are the units of inheritance which are
sequences of DNA (deoxyribonucleic acid) that indirectly produce
proteins such as enzymes, hormones and structural proteins.
a. DNA is a molecule shaped like a double stranded helix that looks
like a twisted ladder.
i.
The two uprights (strands) of the DNA "ladder" are com posed
of phosphate and sugar.
ii.
The rungs are composed of pairs of nitrogenous bases (either
adenine (A) and thymine (T) or guanine (G) and cytosine (C).
b. The sequence of bases along a strand constitutes the genetic code
which gives instructions to perform a specific function such as to
manufacture a particular protein.
i.
Because of the huge number of possible base sequences, DNA
can specify almost unlimited genetic messages for
characteristics of organisms.
ii.
Except for sex cells, cells in the body carry the same genes.
iii. Only a fraction of the genes in any given cell are active.
II. Transmission of an incorrect number of chromosomes can result from
nondisjunctional errors.
A. Chromosomes from a normal body cell can be photographed and arranged
in pairs numbered from largest to smallest (1=largest, 22=smallest, sex
chromosomes not numbered).
1. Eggs can be produced with 21 or 23 chromosomes plus an X
chromosome
2. Eggs can be produced with 22 autosomes without an X or with
two X chromosomes
3. Sperms can be produced with 21 or 23 autosomes plus an X or a Y
chromosome
4. Sperms can be produced with 22 autosomes without a sex
chromosome or with two X, two Y, or both X and Y
B. Sperms and eggs with the wrong number of chromosomes can be
produced as a result of the failure of pairs of chromosomes to disjoin
during gametogenesis.
C. Fertilization that includes a gamete with the wrong number of
chromosomes results in a zygote and subsequently an individual with
chromosomal abnormalities.
1. Most nondisjunctional fertilizations result in spontaneous abortion
(miscarriages), with only a small number of nondisjunctional
individuals involving the smallest autosomes or sex chromosomes
surviving.
2. Trisomy-21 (the presence of 3 copies of autosome 21) results in
expression of Down syndrome.
i. Down syndrome individuals are typically mentally
retarded
ii. Down syndrome individuals typically have a round head,
flat nasal bridge, protruding tongue, small round ears,
spots in the iris of the eye and an epicanthal fold in the eye
lid, poor muscle tone and coordination.
3. Sex chromosome nondisjunctional conditions are more common
than autosomal ones.
i. The XXX condition is not a true syndrome. Only a small
percentage express one or more clinical/behavioral
problems such as irregularity in menstruation, retardation,
sterility or disturbed personalities.
ii. The XYY condition is probably not a true syndrome. XYY
males are typically over six feet and have acne beyond
adolescence. Prison studies conducted in the 1960s which
indicated that XYY males tend to be aggressive/violent,
sterile, below normal in intelligence and tend to have
behavioral disorders have not been substantiated. Some
XYY males are sterile and some mentally retarded.
iii. Turner syndrome females have only one X sex
chromosome (XO). Girls with Turner’s syndrome are
typically short with a webbed neck, lack ovaries and fail to
develop secondary sex characteristics at puberty. Although
usually of normal intelligence, they evidence specific
cognitive deficits in arithmetic, spatial organization and
visual form perception.
iv. Klinefelter syndrome males arise from an XXY zygote.
Although the XXY male may have a small penis at birth,
the syndrome is not evident until puberty when male
secondary sex characteristics such as development of chest
hair, deepening of voice, and further development of the
testes and penis etc. fail to occur. Breast tissue does
develop and fat distribution characteristic of females
becomes evident. Klinefelter’s is characterized by sterility.
Some XXY males are mentally retarded and often have
mental disturbances such as passivity.
III. The genetic make-up of an individual is called its genotype. The expression of the
genes is called its phenotype. Basic principles of genetics are applicable to human
inheritance and expression of genes.
A. Pairs of chromosomes (homologous chromosomes) each have a gene for
the same trait at the same locus on each of the chromosomes (alleles).
B. For traits determined by one pair of genes, if the alleles are the same, the
individual is homozygous for the trait and expresses that phenotypic
characteristic.
1. Whether both genes are dominant genes or both genes are
recessive genes, the alleles will be expressed.
a. Numerous recessive genes are responsible for syndromes
in the homozygous condition.
i.
*Tay-Sachs syndrome produces progressive loss of
nervous function in a baby which becomes obvious
from about six months of age when the baby fails
to sit up, becomes blind, suffers seizures, becomes
paralyzed, dies (usually by age 5).
ii. Albinism arises from a failure to synthesize or store
melanin and also involves abnormal nerve
pathways to the brain resulting in quivering eyes
and the inability to perceive depth or threedimensionality with both eyes.
iii. Phenylketonuria (PKU) results in severe,
irreversible brain damage unless the baby is fed a
special diet low in phenylalanine within 30 days of
birth because the infant cannot digest this amino
acid which can build up and poison cells of the
nervous system. The gene can be tested for.
iv.
Most recessive disorders involve enzyme defects of
metabolism.
b. A small number of dominant genes are responsible for
syndromes and will be expressed in the homozygous or
heterozygous condition. They are usually involved in
tissue development. Huntington’s disease is an example
that involves degeneration of the nervous system.
Progressive symptoms involve forgetfulness, tremors,
jerky motions, loss of the ability to talk, personality
changes such as temper tantrums or inappropriate
accusations, blindness and death. A marker for the gene
has been identified that can be tested for. The onset of
the disease occurs after 30.
2. For alleles on the X chromosome, with no corresponding allele on
the Y chromosome, the allele on the X chromosome will be
expressed in males whether it is dominant or recessive. Recessive
genes for color blindness, hemophilia, and Lesch-Nyhan
syndrome are located on the X chromosome with no
corresponding allele on the Y chromosome. As a result, males
show sex-linked traits much more frequently than females.
a. Color blindness affects about 6% males in the population
by affecting the cones of the retina so that in most cases
red and green cannot be discerned clearly.
b. Hemophilia affects the ability of the blood to clot.
c. Lesch-Nyhan is a metabolic disorder that results in selfmutilation. It affects a very small number of males.
d. For females to show the sex-linked recessive trait, they
would need two recessive genes, one on each X chromo
some.
e. Females with one allele for a sex-linked trait are carriers
and can pass the gene on to sons who will express the trait,
or to daughters who could be carriers or in the ho
mozygous condition express the trait.
C. For traits determined by one pair of genes, if the alleles are different, the
individual is heterozygous for the trait.
1. The dominant gene is the one that is expressed when alleles are
different and only one of the genes is expressed.
2. The recessive gene is the one that is masked when alleles are
different and only one of the genes is expressed. An individual
who is heterozygous for a trait is called a carrier (for the recessive
trait).
3. For some traits, both genes may be expressed as for type AB
blood.
4. For some traits, an intermediate form of inheritance may be ex
pressed as for the sickle-cell trait.
5. Most human traits are polygenic, influenced by more than one pair
of genes. All complex behavioral characteristics such as musical,
artistic, athletic and intellectual aptitudes are influenced by more
than one pair of genes and show continuous variation rather than
distinct categories. What happens to genetic potential depends
upon environmental conditions.
6. Phenotypic characteristics may change over time such as hair
color or may be modified by environmental factors.
D. Behaviors and diseases may have variations only some of which are
genetically based. A form of familial Alzheimer’s disease has been
attributed to a gene on chromosome 21, but not all cases of Alzheimer’s
disease are associated with that gene.
IV. Behavioral genetics research is accomplished by a variety of techniques.
A. Extrapolation from selective breeding experiments in rats, dogs and other
animals has yielded information regarding the genetic and environmental
contributions to excitability, aggression, intelligence, etc. Animals
showing the highest value of a given trait are bred and animals showing
the lowest value of the given trait are selectively bred. With
environmental conditions held constant, if two different "strains" develop
after several generations, a genetic component for the characteristic under
study has been established.
B. Twin studies have been conducted to assess the influence of heredity on
expression of a behavior or constellation of behaviors.
1. Monozygotic (MZ) or identical twins develop from a single
fertilized egg that has split to form two embryos early in
development. Thus they share the same heredity.
2. Dizygotic (DZ) or fraternal twins develop from two different
fertilized eggs. Thus, like other siblings, or each parent and child,
they share about 50% of their genes.
3. In twin studies a particular trait is studied for appearance in sets of
identical twins and sets of fraternal twins. If there is more
similarity in identical twins than in fraternal twins, researchers
infer a genetic component for the trait. Such constellations of
behaviors as schizophrenia and general intelligence have shown
greater similarity in identical twins than in fraternal twins, for
example. These studies are not controlled experiments.
C. Adoption studies assess genetic influence by comparing resemblance of
adopted children to both their adoptive and biological parents. The
children must have been adopted as infants without contact with their
biological parents. If the children resemble their biological parents, but
not their adoptive families, with respect to a given trait, researchers infer
a genetic component for that trait. Such constellations of behaviors as
alcoholism, schizophrenia and general intelligence have shown both
genetic and environmental components.
D. The Human Genome Project is an international effort to map the loci of
all of the genes on the twenty-three chromosome pairs in humans.
Techniques of biotechnology have been employed to close in on locations
for genes for Alzheimer’s, Huntington’s, Duchenne muscular dystrophy.
The DNA sequence for some genes has already been established.
E. Social values, prejudices and fallacies are imposed on our biological
understanding of race and other polygenic inheritances.
Lesson 2
Major issues, methods, prenatal development, infancy
I.
II.
III.
IV.
Development involves the processes and stages of growth from conception across
the life span. It encompasses changes in physical, cognitive and social behaviors.
Major issues
A. Nature versus nurture-are we more affected by heredity or environment?
B.
Continuity versus discontinuity-is developmental change gradual, or do
we progress through distinct stages ?
Methods
A. Cross-sectional research involves studying a variety of ages at a given
point in time.
B.
Longitudinal research follows the same group of subjects for many years.
C.
In cohort-sequential research, several age groups are studied periodically.
D. Historical research revolves around the particular historical circumstances
of an era.
Prenatal development
A. Physical development
1.
Cephalocaudal (head to tail) development
2.
Proximodistal (from the center outward) development
3.
Germinal Stage- Zygote- 10 days
4.
Embryonic Stage- after that- Cells begin to differentiate,
specialize and form organs, form distinct layers. Most
miscarriages will occur during this stage, embryo is very
vulnerable.
5.
Fetal Stage- Two months until birth. Fetus becomes capable of
physical movement, organs formed, brain cells multiple at a rapid
rate, respiratory and digestive systems mature. Age of viabilityage at which the baby can survive in the event of premature
delivery. Between 22 and 26 weeks.
B.
C.
V.
Genetics
1.
Genotype refers to the total genetic composition of a person.
2.
Phenotype refers to the observable features of the person.
Teratogens are disease agents, drugs and other environmental agents that
can cause birth defects during the prenatal period.
Infancy
A. Physical development
1.
Growth rate declines throughout infancy but is faster than during
any other postnatal period.
2.
Maturation and learning combine to determine skill development
and replace reflexes.- Maturation is the gradual unfolding of one’s
genetic blueprint. Skills develop because neural connections have
been made. This is why some kids walk sooner or later.
a.
Reflexes- babies are born with certain types of reflexes
like: Moro, grasping and rooting.
b.
Developmental norms- see slide
B.
Social development
1.
Harry Harlow's surrogate mother research with monkeys
demonstrated the importance of contact comfort.
2.
Konrad Lorenz- Critical period and imprinting. Baby animals will
imprint on whoever is their mother. Animals have critical periods
in which things need to happen (like dogs and socialization).
3.
Attachment style – Mary Ainsworth- Attachment refers to the
close, emotional bonds of affections that develop between infants
and their caregivers. Mary Ainsworth tested this with her Strange
Situation (situations where the child is separated from their
caregiver) Test. Attachment is not instantaneous,
a.
Secure attachment means the infant seeks proximity,
contact, and interaction with the caregiver after separation.
The child will explore novel situations if the caregiver is
near.
b.
Insecure attachment means the infant cannot be calmed or
ignores the caregiver after separation
c.
Anxious Ambivalent- appear anxious even when mother is
near and protest excessively when she leaves, but are not
comforted when she returns.
Avoidant – Children seek little contact with their
caregivers, and often are distressed when they leave.
4.
Stranger anxiety peaks at about 6 months; separation anxiety
peaks at about 18 months.
5.
Temperament- refers to the characteristic mood, activity level and
emotional reactivity. Thomas and Chess found that temperamental
individuality is well established by the time the child is two or
three months old. Temperament seems to be stable throughout life,
questions about this study since it is based on the self report data
from parents.
a.
Easy- Tend to be happy, regular in sleep and eating,
adaptable and not easily upset. 40%
b.
Slow-to- Warm- tend to be less cherry, less regular in sleep
and slower to adapting to change.- 15%
c.
Difficult children- tend to be glum, erratic in sleep and
eating, resistant to change and relatively irritable – 10%
d.
Not one category- they don’t fit into one category.
Cognitive development
1.
Infants show a preference for face-like patterns.
2.
Visual cliff experiments suggest that infants perceive depth by the
time they are able to crawl.
d.
C.
Lesson 3
Childhood and adolescence
I.
II.
Childhood
A. Physical development (what things can we identify that happen)
1.
More extensive neural networks continue to develop in the brain.
2.
Growth rate continues to decline.
B.
Social development1.
Interaction with the environment provides a sense of gender
identity.
2.
A greater sense of independence develops as peer relationships
begin td become more important.
C.
Cognitive development continues at a rapid rate. There are advances in the
areas of
1.
Learning
2.
Language
3.
Thinking skills
Adolescence
A. Physical/ sexual development-puberty is when sexual functions reach
maturity, meaning a person can reproduce
1. Primary Sex Characteristics- changes at puberty that relate to
reproduction (ovulation, sperms, eggs, etc.)
2. Secondary Sex Characteristics- Changes at puberty that are not
directly related to reproduction- such as facial and body hair and
breast tissue development.
B. Social development –Adolescence is a relatively modern term when you
look at history because children worked or girls got married at puberty.
1. Peer groups take on an increasingly important role.
2. Opposite-sex relationships gradually become less recreational and
more intimate.
C. Cognitive development
1. Capability for logical, hypothetical, and introspective thinking
develops.
2. Growing awareness of one's own mental processes developsmetacognition. – Thinking about thinking
D. Adolescent development relates to many important societal problems,
such as suicide, teen pregnancy, and eating disorders.
E. G Stanley Hall- Storm and Stress- Proposed that the adolescent years are
characterized by convulsive instability and disturbing inner turmoil. Clash
with parents about everything. Not so much true- research shows that a
small percent of kids have serious issues and a high percent of kids
actually agree with parents.
F. James Marcia- Answering the question, “Who am I and where am I
going” must be addressed. Crisis and commitment can combine to
produce these identity statuses. Many psychologists believe adequate
identity formations is the cornerstone of sound psychological health.
1. Foreclosure- you have accepted your parent’s identity without
questioning or searching for your own identity.
2. Moratorium- normal search for who you are- work a job for two
weeks, quit. Go out with someone, break up…
3. Identity diffusion- absence of struggle for identity with no obvious
concern about it.
4. Identity Achievement- You have gone through the struggle and
come out with a sense of who you are.
G. Types of parents
1. Authoritatative- have high expectations, explains rules, negotiates
rights and responsibilities with children. Children of these parents
achieve the most positive outcomes. Have high self-esteem,
popular with peers, self-reliant, competent. Encourages children
to be independent and assertive, but respectful of others.
2. Authoritarian- Parents impose rules and expect obedience. These
children tend to be moody, inhibited, withdrawn, fearful and
distrustful of others.
3. Permissive- Parents make few demands and rarely punish. The
parent usually is loving, but has an anything goes attitude. Child
tends to be impulsive and lack self-control. Lack of experience in
conforming to the other people’s demands.
4. Uninvolved- indifferent or rejecting. Don’t have the energy or
time.
Lesson 4
Piaget and Kohlberg
I.
Piaget's theory of cognitive development refers to transitions in children’s
patterns of thinking including reasoning. Piaget asserted the interpretation
between the environment and maturation gradually alter the way children thing.
A. Sensorimotor stage, birth to 18 months – Very little thinking, reflexive
responses, simple learning. It is all about interaction with objects.
1.
Characteristics
a.
Cognitive structures or schema are the mental structures
that guide thinking (things like being able to label
something as a cat or a dog)
b.
Assimilation is the use of available cognitive structures to
gain new information (we fit new information into existing
schemas)
c.
Accommodation is the process of modifying cognitive
structures in the face of newly realized complexities in the
environment (we restructure our schemas to fit new
information)
2.
Developmental achievements
a.
Circular reactions are repetitive motions babies engage in
as they gradually learn to explore their environment
nonreflexively.
b.
Object permanence is the understanding that objects
continue to exist even when hidden from view (happens at
about 8 months)
B.
Preoperational stage, 18 months to 6 years- this stage stems from the
growing ability to represent objects mentally. There is an emerging sense
II.
of distinct self and they can solve simple problems using mental
representations.
1.
Characteristics
a.
Egocentrism is a limited ability to comprehend a situation
from a perspective one has not experienced. (the child
assumes that others see the world from their view)
b.
Animism is the tendency to attribute life to inanimate
things.
c.
Artificialism is the tendency to believe everything is the
product of human action
d.
Centration- focuses attention too narrowly
e.
Irreversibility- can’t do something and then undo an event
in their mind (they can’t bake a cake and then tell you that
it was made up of other objects like eggs, flower, etc.).
2.
Developmental achievements
a.
Symbolic representation and language
b.
Readiness for operational thought
C.
Concrete-operational stage, 6 years to early adolescence. They have a
break through in irreversibility. (A child in this stage when playing a
game like 20 questions will say “is it a bird?” or “is it a cat?” instead of
asking questions like “does it fly” or “does it have fur”)
1.
Characteristics
a.
Use of simple logic
b.
Use of simple mental manipulations- they are less gullible
2.
Developmental achievements
a.
Conservation is the principle that matter does not increase
or decrease because of a change in form.
b.
Reversibility is the understanding that mathematical
operations can be undone.
c.
Class inclusion is the ability to understand the hierarchical
nature of classification groups.
D. Formal-operations stage, adolescence and adulthood; they can deal with
abstract and intangible issues.
1.
Characteristics
a.
Hypothetical and deductive reasoning
b.
Propositional logic
2.
Developmental achievement indicates a readiness for adult
intellectual tasks.
3.
Not all adolescents or adults achieve formal operational reasoning
ability.
E.
Critique of Piaget
1.
Development may be more gradual than Piaget's stages imply.
2.
The nature of Piaget's tasks may have underestimated cognitive
skills of children.
Kohlberg's theory of moral development
A. Preconventional level
B.
C.
D.
1.
Stage 1, characterized by
2.
Stage 2, characterized by
Conventional level
1.
Stage 3, characterized by
2.
Stage 4, characterized by
Postconventional level
1.
Stage 5, characterized by an understanding that values and rules
2.
Stage 6, characterized by universal
Critique of Kohlberg
1.
Development may be more gradual and less sequential than
Kohlberg's stages imply.
2.
Gilligan and others have criticized the theory for undervaluing
traditional female traits, which focus on interpersonal issues.
Lesson 5
Erikson's psychosocial theory of development
I.
II.
III.
Background
A. Erikson was trained in the Freudian tradition, and the first four stages
borrow from Freud's psychosexual stages.
B.
The developmental task of each stage involves resolving the tension
between two opposite outcomes.
The stages (slides)
A. Trust versus mistrust - infants
B.
Autonomy versus shame and doubt - toddlers
C.
Initiative versus guilt - young children
D. Industry versus inferiority - older children
E.
Identity versus role confusion - adolescents
F.
Intimacy versus isolation - young adults
G. Generativity versus stagnation - adults
H. Ego integrity versus despair - elderly
Critique of Erikson
A. There is no agreed-upon set of measures for the various stages.
B.
The stages imply a rigidity of development that may not exist.
C.
The theory may not reflect differences in personality development
between men and women.
Lesson 6
Adult and later years
I.
Adulthood
A. Physical changes
1.
Abilities peak and begin a gradual (1% a year) decline. Physical
peak around 20- Hair will thin, weight gain, sensory acuity
decreases…
2.
Women undergo menopause with its hormonal and reproductive
changes. Menopause marks the end of reproduction for a female.
(typically)
B.
Social changes center around such issues as:
1.
Mate selection
2.
Parenting
3.
Career selection
C.
Cognitive changes vary significantly with some people showing declines
and others not.
1.
Reaction time appears to decline.
2.
Some adults show a decline in memory.
D. Midlife crisis- reappraisal of one’s life. Start to think in terms of time left, not
how many years you have lived. Change in family life. More prevelant in men,
women this is usually a better time in life, kids are gone.
II.
Later years
A. Physical changes
1.
There is a general decline in muscle tone and sensory abilities.
2.
Senile dementia and Alzheimer's disease are two disorders that
may develop.- SD is an abnormal condition, not automatic that all
old people are like this.
B.
Social issues include:
1.
Retirement
2.
Social isolation which may be caused by loss of spouse and others
lack of mobility and declining health
C.
Cognitive declines are likely to continue.
1.
Crystallized intelligence- application of accumulated knowledge
tends to remain stable.
2.
Fluid intelligence- basic information processing skills (how fast
you think) will decline as you age. Intelligence doesn’t decline
thinking speed declines.
D. Elisabeth Kubler Ross- 5 stages of death- Denial, Anger, Bargaining,
Depression, Acceptance.