Prenatal Development Stages

Prenatal Development

• Prenatal development is composed of germinal, embryonic, and fetal stages.

• The germinal stage is 0-2 weeks with the single egg fertilized by sperm which is called a "zygote"

• Implantation happens when the attachment to the lining of the uterus

• The blastocyst consists of inner and outer layers of cells which will form the embryo and placenta.

• The embryonic stage is 2-8 weeks and the "Embryo" forms

• The neural tube develops

• Formation of facial features, head, arms, and legs occurs

• The brain, spinal cord, heart, and lungs develop

• A heartbeat is detectable with an ultrasound.

• The fetal stage is 8 weeks to birth and called "fetus"

• Skeletal, organ, and nervous systems become specialized during this stage

• Motor systems allow movement

• Sensory systems allow responses to stimuli

• At 12 weeks, differentiation occurs between cerebral hemispheres, the cerebellum, and the brainstem.

• At 28 weeks, the cortex develops gyri and sulci, and myelin production occurs.

• At 40 weeks, newborn brains have virtually all the neurons of an adult brain, and more.

Prenatal Environment

• Nutrition is a factor in the prenatal environment that can lead to low birth weight, developmental delays, and disease susceptibility if not sufficient.
• Teratogens are environmental agents such as drugs (e.g., thalidomide), pollutants, and diseases (measles, AIDS) that interfere with typical development.
• The strongest effects of teratogens occur during the embryonic period.
• Fetal Alcohol Spectrum Disorder can cause learning disorders, behavioral difficulties, and differences in facial structure.

The Infant's Brain

• The brain forms neuronal connections.
• Synaptogenesis forms new synaptic connections at a tremendous speed.
• Synaptic pruning is the loss of weak connections.
• Critical or sensitive periods are periods of time when neural development is strongly dependent on or influenced by experience.
• An example is early exposure to visual information.
• Blakemore & Cooper conducted a study in 1970 showed kittens exposed to only vertical or horizontal stripes unable to detect objects aligned in the opposite way.

Motor Development: Newborn Reflexes

• The rooting reflex causes an infant to move his or her head toward the hand when the cheek is stroked.
• The infant will seemingly look for something to suck
• The Moro reflex is a startle response that causes the infant to arch back, throw back the head, fling out arms and legs, and pull arms back inward in a hugging motion.
• The grasping reflex occurs when something touches the infant's palms, causing the infant to grasp it tightly.

Motor Development

• The sequence of motor development is generally consistent, involving raising the head, rolling over, sitting up, crawling, standing, walking, and running with variability in timing.
• Maturation is when children develop abilities biologically in genetically determined time frames.

Sensory Development

• The auditory system is well developed by birth.
• Babies prefer stories read in the womb (e.g., "The Cat in the Hat" and pacifier study).
• There is a strong preference for a mother or pregnant parent's voice
• Babies cry with accents as French babies' cries rise in intensity and German babies' cries trail off with differences present days after birth.
• The visual system is not well developed
• Visual acuity is 1/40th of that of an adult
• Color vision develops at 2 months, and depth perception at 4 months.
• Experience is vital through elements like a visual cliff.
• There are strong social preferences.
• Newborns prefer to look at objects 8-12 inches away, which is the distance between a feeding infant's face and caregiver.
• Newborns also look to voices and prefer face-like displays.

Piaget's Core Ideas

• A schema is a flexible concept or framework that helps make sense of information by organizing & interpreting it.
• Assimilation uses an existing schema to interpret new information.
• Accommodation revises an existing schema to incorporate new information

Sensorimotor Stage (0-2)

• The world is taken in through sensations and motor experience with no symbolic thought.
• Object permanence is the awareness that objects continue to exist when out of sight.
• Piaget stated that infants can only think about the physical world; the ability does not develop until 8-12 months.
• The current understanding is that it develops as early as 3.5 months.
• Violation-of-expectation method (VOE) measures object permeance

Preoperational Stage (2-6)

• The preoperational stage involves the development of a capacity for symbolic thought where the world is represented with words, sounds, gestures, and images.
• Language develops
• The child engages in imaginative or pretend play.
• The child is unable to manipulate symbolic schemas or perform operations.
• Conservation is the principle that quantity remains the same despite changes in shape or form.
• Egocentrism is the difficulty that children have imagining how others perceive something.
• Theory of mind is understanding that others have beliefs, desires, perceptions, and emotions different from one's own.
• A test for the theory of mind is the Sally-Anne test.

Concrete Operational Stage (7-11)

• This stage involves the capacity to think logically, but only about concrete events.
• Children now understand conservation and reversibility.
• Conservation: Quantity remains the same despite changes in shape
• Reversibility: Things can be changed and then returned to their original state.

Formal Operational Stage (12-adult)

• Adolescents are now able to think abstractly and mentally manipulate ideas and problems without physical objects.
• They can think about hypothetical problems and possible occurrences.

Conclusions about Piaget's Theory

• Piaget's stage theory had global influence on the field.
• Current researchers believe that development is a more continuous process
• Children express their mental abilities and operations at earlier ages than Piaget believed.
• Understanding development is important for good caregiving in teaching and parenting.

Morality: Pre-Conventional ( <9 years)

• This is also known as "Pre-moral"
• Morality is self-interested
• Children obey to avoid punishment, as noted by the statement, "I won't cheat because I would get in trouble."
• Children obey to obtain rewards, as noted by the statement, ""I'll clean the bathroom because I'll get $5."

Morality: Conventional (adolescence)

• This is also known as "Role conformity”
• Regards social conventions as moral guides
• People uphold laws and rules because they are rules
• The participant may say "I won't cheat because it's the rule"
• Possible approval of actions that maintain social order

Morality: Post-Conventional (Adulthood)

• This is also known as "Self-accepted moral principles"
• Affirms people's agreed-upon rights
• Follows what one perceives to be basic ethical principles
• A test subject may say, "I don't cheat because it's wrong; it's unethical."

Criticisms of Kohlberg's Theory

• Gender bias: Kohlberg's studies were conducted exclusively with men or boys.
• Women are more likely to consider compassion and social relationships in moral judgments.
• Cultural bias is present as Research focused on North American samples
• More concrete forms of morality may develop in cultures with more face-to-face encounters.

The Attachment System

• In the 1950s, the prevailing view was that infants bond with their mother because she feeds and diapers them
• Harry Harlow and John Bowlby stated that emotional bonding is an innate, powerful need
• Harlow did rhesus monkey experiments that preferred the terrycloth "mother” (vs. wire) regardless of who provides milk
• Bowlby stated that orphans fail to thrive due to being undersized and disengaged without emotional security provided by maternal care
• Attachment: This is a strong emotional bond between infant and caregiver.
• Three functions of attachment (first identified in infants):
• Proximity maintenance: Seeking and sustaining physical closeness
• Safe haven: Returning for comfort and reassurance when in need of support
• Secure base: Using the attachment figure as a foundation for confident play and exploration

Attachment Styles

• Individual differences and the "Strange situation” (Mary Ainsworth).
• Examines a child's reaction to three key situations: exploration, caregiver leaving, and caregiver returning.
• Attachment styles are characteristic patterns of relating to others based on history with a caregiver and temperament.

The styles are below:

• Secure: Infants trust a responsive caregiver, feel comfortable to explore (secure base), minor distress, easily comforted
• Ambivalent: Infants cling to inconsistent caregiver, and do not explore, protest extremely, and are not easily comforted.
• Avoidant: Infants appear detached from unresponsive caregiver, and do not appear distressed, but have elevated heart rates.
• Disorganized: Infants alternate between wanting to get away and wanting to be comforted

Adult Attachment

• People with secure attachments find it relatively easy to get close to others and are comfortable depending on them, and they do not often worry about being abandoned.
• People with anxious or ambivalent attachment styles find that others are reluctant to get as close as they would like, and they often worry that their partner doesn't really love them.
• Avoidant types are uncomfortable being close to others and find it difficult to allow themselves to depend on others
• Those that identify as fearful and disorganized want emotionally close relationships, but find it difficult to trust others completely or to depend on them.
• Infant attachment style predicts the nature of adult relationships.
• Secure relationships display more commitment, trust, and intimacy plus little conflict, jealousy, or negative emotion and better relationship quality, satisfaction, and outcomes.
• By contrast, insecure attachments have these qualities:
• Relationships on "hard mode"
• • Anxious will be jealous, clingy, controlling, and over-perceive conflict
• • Avoidant will have lack of support and emotional and physical infidelity

Erikson's Psychosocial Development

• Development is a lifelong process that progresses through eight stages.
• Each stage has a key challenge (psychosocial crisis) to resolve.
• How these are resolved can impact personality development.
• Stage 1 Trust versus Mistrust, infant, where the person will form attachment and develop trust and security.
• Stage 2 Autonomy versus Shame/Doubt, toddler, which will develop personal control and independence.
• Stage 3 Initiative versus Guilt, preschool, which will make them try things out, exerting control over the environment.
• Stage 4 Competence versus Inferiority, childhood, and it will help them learn to cope with social and academic demands.
• Stage 5 Identity versus Role Confusion, adolescent, which will develop a sense of identity, values, and goals.
• Stage 6 Intimacy versus Isolation, early adult, and will establish intimacy and close relationships.
• Stage 7 Generativity versus, middle aged, which will have them contribute to family and society.