Human Development
Development Parenting styles Cognition
DNA
Theories of development Conception
Genes
Developmental theorists Assimilation
Genotype Teratogenic effects Threshold effect
Phenotype Imprinting
Accommodation
Gamete
Stranger anxiety Germinal stage
Zygote
Theory theory
Embryonic stage
Attachment Theory of mind Fetal stage
Interaction effect Apgar scale Critical periods
Addiction
Dizygotic/Monozygotic twins
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The sperm and ovum receive only one member of each chromosome pair when cells
divide to produce gametes, and thus have only 23 single chromosomes each
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Gamete-a reproductive cell, a sperm or ovum that can produce a new individual if it
combines with a gamete from the other sex to make a zygote
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Zygote- the single cell formed from the fusing of two gametes, a sperm & an ovum
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How does conception occur?
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Conception occurs when the male gamete (or sperm) penetrates the membrane of
the female gamete (the ovum); the gametes fuse and their genetic material
combines to form one zygote
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Where does the zygote develop?
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The amniotic sac is the fluid-filled pouch in which the embryo will live until birth
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The amniotic sac acts as both a cushion against the environment and as a
temperature regulator
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The 23rd pair of chromosomes determines the sex
The chemical on the Y chromosome signals the development of the male organs
The chromosomal make up is XY in the male and XX in the female
In a stressful pregnancy, XY embryos are more likely than XXs to be expelled in a
spontaneous abortion, or miscarriage
Within hours, the zygote initiates human development through the process of
duplication and division
Implantation begins about 10 days after conception, the organism buries into the
placenta for nourishment
Then differentiation begins, this is when cells begin to specialize, taking different
forms and reproducing at various rates
At the eight-cell stage, the organism has stem cells it could develop into a body
part
The cells on the outer side of the of the mass become the placenta-the organ that
will support the life
Certain genes begin to switch on an off during this developmental stage
In some pregnancies, a single zygote splits into two separate identical cells that
develop into genetically identical or monozygotic (MZ) twins
MZ twins have the potential for developing the same physical appearance and
psychological characteristics, but they are also vulnerable to specific diseases
Dizygotic (DZ) or fraternal twins begin life as separate zygotes, and share no more
genes than any other sibling (about 50 percent)
Gestation
• The 1st 2 weeks of prenatal development are
called the germinal period
• The embryonic period begins in the 3rd week
as the formless mass becomes a distinct
being, which is now referred to as an embryo
• A thin line down the middle of the outer layer
of cells is the primitive streak, and the
structure becomes the neural tube, then the
brain and spinal column (the central nervous
system)
• The third week to the eighth week begins the
embryonic phase…the developing mass can now be
considered an embryo
• 5th – 6th week: primitive gonads form
• 7th – 8th week: gonads become testes with Y
chromosome and the SRY gene
• In the 4th week, the cardiovascular system is
functioning; the eyes, ears, nose, and mouth start to
form
• At 5 weeks, the arm and leg buds appear and the
primitive heart is now visible
• By the end of the 2nd month, the developing organism
has all the basic organs and body parts of a human
being, and a unisex structure called the indifferent
gonad
• The fetal period-from the 9th week after
conception, the sex organs begin to take
shape
• By the 12th week, the genitals are fully formed
• A sonogram is readable
• By the 12th week, the genitals are fully formed
• A sonogram is readable
• At the end of the 3rd month, the fetus has all its body
parts
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• *22 weeks-signals the age of viability- the ability of the
fetus to live outside of the body
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• During this time, the brain develops new neurons in a
process called neurogenesis and new connections
between them in a process called synaptogenesis
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• Weight gain during the final 3 months is 41/2 pounds
• The neurological, respiratory, and cardiovascular
systems mature dramatically; brain growth is so
extensive that the brain’s cortex must fold into layers in
order to fit into the skull
Variables that may affect the fetus…
• Teratology is the study of birth defects; teratogens include
such substance as viruses, drugs, chemicals, stressors, and
environmental hazards that can impair developmental and
lead to birth defects and even death
• The critical periods are times when the body is most
susceptible to teratogenic damage
• For behavioral teratogens that affect the brain and nervous
system, the entire prenatal period is critical
• For some teratogens, the threshold effect is imperative;
this means that the substance is not harmful until the
chemical reaches a certain level
• The interaction effect of teratogens occurs when one
teratogen intensifies the impact of the other
• Zygotes that are formed from abnormal or fragile gametes
may not duplicate, divide, or differentiate
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• * the variable that most often correlates with
chromosomal abnormalities is the mother’s age
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• The most common of the extra-chromosome syndrome is
Down Syndrome (trisomy 21)
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• Persons with Down Syndrome exhibit distinguishing
features of the slanted eyes, rounded face, and a thick
tongue
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• the extra chromosome at site 21 also makes them more
susceptible to heart defects, slow intellectual development,
and by middle age Alzheimer’s disease it’s inherited
• *people with this syndrome age faster than other adults
Baby is born!
What are reflexes?
• Reflexes are involuntary responses to stimuli
• What are some examples of reflexes?
• Rooting, Babinski, stepping
• The infant is born around the 38 week of pregnancy (9 ½ months)
• Newborns are born with survival reflexes that prepare them for
their new world
• Tonic neck reflex
• When the baby is laid on its back, baby turns its head and extends
arms to same side, helps develop eye/hand coordination
• Moro reflex
• When baby is dropped or hears a loud noise, baby extends arms
and legs and quickly brings them in as if trying to grasp something
• Withdrawal reflex
• When a soft pinprick is applied to baby, the sole of baby’s foot,
baby flexes the leg, helps protect the infant from harmful stimuli
Motor Development
First, infants begin to roll over. Next, they sit
unsupported, crawl, and finally walk.
Experience has little effect on this sequence.
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Baby Preferences
• The infant is born with an acute auditory
sense? Why do you think this is?
• Newborns have a preference for human faces,
which human face do you think newborns
prefer most?
• Newborns have a preference for the smell of
their mother’s milk
• Newborns have a preference for sweet tastes
How the brain develops
Cognitive Development
Cognition refers to all the
mental activities associated
with thinking, knowing,
remembering, and
communicating.
Developmental
psychologist Jean Piaget
believed that children
reason differently than
adults and that a child’s
mind develops in a series of
stages.
Jean Piaget (1896–1980)
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Schemas
Piaget felt that the driving force behind our intellectual
progression is an unceasing struggle to make sense of
our experiences and that to do this maturing brains
build schemas.
Schemas are concepts or frameworks that
organize and interpret information.
To use our schemas Piaget proposed that we assimilate
new experiences, or interpret them according to our
schemas and then adjust or accommodate our schemas
accordingly.
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• Theory-theory is the idea that children attempt to
construct theories to explain everything they see and hear
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• As preschoolers develop informal theories that attempt to
answer basic question about mental process-thoughts,
emotions, beliefs, motives, and intentions-they acquire a
theory of mind
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• By age 4, young children come to realize that mental
phenomena may not reflect reality and that people can
deliberately deceived or fooled
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• Theory of mind is strengthened by a combination of factors,
including maturation of the brain’s prefrontal cortex
• Schemas- our understanding of the world
Erik Erikson, Psychosocial Development
• Erikson maintains that development occurs
through a series of basic crises.
• Erikson describes the basic crises of infancy and
toddlerhood as those of trust v mistrust and
autonomy v shame and doubt
• In Eriksons’s view, parental guidance and
protection are the keys to the child’s gaining a
healthy sense of autonomy.
• Infants who fail to develop trust or achieve
autonomy may become adults who are suspicious
and pessimistic or who are burdened by shame.
Gender Identity
• Sex is defined by biology
• The child learns to identify themselves as male
or female…body shape, pregnancy
• Gender is defined by the child’s culture
• Gender is a shared cultural definition of what
it means to be masculine or feminine
• Gender roles are cultural expectations about
the appropriate behavior for each gender
Freud’s Psycho-Sexual Theory
• Freud suggested that children identify with
their same-sex parent
• Identification provides the foundation for
gender identity
• Anxiety and a desire for power provides the
motivation for identification
• Focusing on emotional identification is one
way to explain the powerful gender roles that
most people accept as part of their selfconcept
Attachment
• Mary Ainsworth has developed laboratory procedure
for measuring the security of attachment
• The procedure is called the Strange Situation-infants’
reactions to the comings and going of their mothers
and to friendly strangers are monitored
• Fully formed fear emerges at about 9 months. One
expression of this new emotion is stranger wariness,
which emerges between 9 and 14 months; another is
separation anxiety, or fear of abandonment, which
becomes most obvious at 9 to 14 months.
• Approaching and following their caregivers are signs of
proximity-seeking behaviors, while holding and
cuddling are signs of contact; maintaining these
behaviors are signs of attachment
• A secure attachment (TypeB) is one in which the
infant derives comfort and confidence from the
caregiver-this is a type of attachment in which
the caregiver acts as a base for exploration
• Insecure-avoidant attachment (Type A)-infants
who display insecure attachment may engage in
little interaction with their mothers and show no
apparent distress when they leave
• Insecure-resistant/ambivalent
attachment(TypeC)- infants show an inconsistent
mixture of behavior toward their mothers, such
as both resisting and seeking contact
• Disorganized attachment (TypeD)- found in the
most troubled infants
• Contact is a key to attachment
• Familiarity is another key to attachment
• Critical periods are the optimal periods when
certain events must take place to facilitate
proper development
• Parenting styles will foster attachment in later
developmental stages
• Parenting styles
• Authoritarian, Authoritative,Permissive,Neglectful
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According to epigenetic theory, every human characteristic is strongly influenced
by each person’s unique genotype
Temperament refers to “constitutionally based” individual differences in emotions,
activity, and self-control
Infants are born with distinct temperaments that are genetic in origin and affect
their personality
Personality traits are generally considered to be primarily learned; temperamental
traits are considered to be primarily genetic
According to the New York Longitudinal Study (NYLS), infants can be described as
possessing one of four temperaments:
1. easy-(40 percent)
2. slow to warm up-(15 percent)
3. difficult-(10 percent)
4. hard to classify-(35 percent)
• An important factor in healthy psychosocial
development is the goodness of fit between
the developing child and the caregiving
context
• If attachment is not developed between
caregiver and infant, severe depression or
other serious problems may arise…post
partum depression, developmental delays,
failure to thrive
• Failure to thrive is the diagnosis for an infant
who does not grow, develop, or gain weight
on schedule
Social Development
Stranger anxiety is the fear of strangers that develops at
around 8 months. This is the age at which infants form
schemas for familiar faces and cannot assimilate a new
face.
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• Adolescence begins with puberty…puberty
indicates sexual maturity (only)
• Puberty refers to the rapid physical growth and
sexual maturation that end childhood, eventually
producing a person of adult size and sexual
potential
• Primary sex characteristic- the reproductive
organs and external genitalia
• Primary sex characteristics refer to organs
involved in conception and pregnancy…vagina,
uterus, ovaries, testicles, and penis
• Secondary sex characteristics-the nonreproductive traits such as breasts and hips, facial
hair and deepened voice in boys
• For girls, the sequence of biological changes of
puberty is….
• The growth of nipples
• First pubic hairs
• Height spurt
• First menstrual cycle, menarche
• Final pubic-hair growth
• Full breast development
• The first set of publicly visible changes during
puberty is the growth spurt…a sudden, uneven
increase in the size of almost every body part
• Sex hormones
• In adolescence, the pituitary glands activate the gonads or
the sex glands…the gonadotrophin-releasing hormones
causes the gonads to increase production of estrogen and
androgens…estrogen for girls and testosterone for boys
• The sex hormones affect the body’s shape and functioning,
including production of other hormones that regulate
stress and immunity…estradiol and testosterone levels may
also explain sex differences in psychopathology
• The behaviors triggered by hormones are responses to
moodiness and lust
• Certain behaviors are influenced by
biology…aggressiveness, males produce more testosterone
• Culture influences the gender roles, thus influencing how
those behaviors manifest
• Culture/biology influences sexual behaviors
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Age of puberty varies among ethnic groups, most likely because of genes…African
American females reach puberty earlier than others
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For both sexes, malnutrition delays puberty…the secular trend indicates that it
causes puberty to start earlier and make people shorter, and has stopped in
developed nations
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Stress affects puberty hormones by increasing production
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Cohorts are also influencing for early maturing boys…delinquency training
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Early maturing girls tend to experience depression, have more boyfriends, lower
self-esteem, and poorer body image
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Early maturing males engage in delinquent behavior, start drinking earlier, engage
in sexual behaviors earlier, and are more aggressive than later maturing boys
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Later maturing boys also engage in delinquent behavior which may be due to
depression and self-esteem issues, afraid of sex, and more anxious
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Development continues into the emerging adulthood period…cognitive,
psychosocial
Emerging Adulthood
Emerging adulthood spans from the late-teens to the midtwenties. During this time, young adults may live with
their parents and attend college or work. On average,
emerging adults marry in their mid-twenties.
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3 Basic Levels of Moral Thinking
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Preconventional Morality: Before age 9, children show
morality to avoid punishment or gain reward.
2.
Conventional Morality: By early adolescence, social
rules and laws are upheld for their own sake.
3.
Postconventional Morality: Affirms people’s agreedupon rights or follows personally perceived ethical
principles.
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Kohlberg’s, Moral development
• Level I (preconventional)
• Stage I-Obedience and Punishment orientation (similar to Piaget 1st
stage) –It’s wrong to steal because you’ll get punished, rewards
from the outside world
• Stage 2-Individualism and Exchange-different individuals have
different viewpoints –What’s in it for me? (self-interests),
punishments from the external world
• Level II (conventional)
• Stage 3-Interpersonal accord and conformity- social norms-people
should live up to others’ expectations of the family and community
and behave in good ways-he loves his wife; no husband should let
his wife die (good boy/g) adolescents value loyalty to others as a
basis for moral judgments
• Stage 4-Authority and Maintaining Social Order-obeying the law,
respecting authority-what would happen if we all started stealing?
Cannot condone theft social order, justice and duty are important
in making decisions
• Level III (Post conventional)
• Stage 5-Social Contract and Individual Rights-it
is a human’s basic right to live and this
supersedes the law (moralistic) the
importance of individual rights are the basis
for moral decisions
• Stage 6-Universal Principles-there should not
be a law that protects some and hurts others(
uphold social contracts and laws that promote
a good society) universal ethical principles,
complete selflessness
Marica’s Stages of Identity
Development
• Identity-diffusion the individual does not
have firm commitments regarding the issues
in question and is not making progress toward
them
• Foreclosure-the individual has not engaged in
any identity experimentation and has not
established an identity based on the choices
or values of others
• Moratorium-the individual is exploring various
choices but has not yet made a clear
commitment to any of them
• Identity achievement-the individual has
attained a coherent committed identity based
on personal decisions
• During this time of identity development,
adolescents rely less on parents’ views and
defer instead to peers
Cognitive changes in late adulthood
• As neurogenesis slows down, the memory
functions decrease
• Crystalized intelligence, accumulated
knowledge may remain stable, but fluid
intelligence, intelligence for reasoning,
thinking quickly and abstractly declines
• Older adults may find it necessary to resort to
memory cues…
Aging and Memory
• Recognition memory does
not decline with age, and
material that is meaningful
is recalled better than
meaningless material.
• Some older adults suffer
from biologically based
cognitive impairments in
which the brain is so
adversely affected by aging
that it becomes very
difficult for the person to
continue to function
effectively.
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Successful Aging
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Death and Dying
The “normal” range of reactions or grief stages after the death
of a loved one varies widely. Grief is more severe if death
occurs unexpectedly. People who view their lives with a sense
of integrity (in Erikson’s terms) see life as meaningful and
worthwhile.
Life satisfaction before, during the year of, and after a spouse’s death
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