Prenatal Stages Slides Biological Foundations
Prenatal Stages and Environmental Risks
Week 1: Developmental Psych | 11th Grade Psychology
Doctor's Dilemma
If you were a doctor advising a patient, how would you explain why exposure to a virus in Week 5 is drastically different than in Week 30?
"The difference isn't just time—it's what is being built at that exact moment."
The Prenatal Roadmap
Stage 1
Germinal
Conception to 2 Weeks
Creation of Zygote
Rapid Cell Division
Implantation in Uterine Wall
Stage 2
Embryonic
2 to 8 Weeks
Critical Period: OrganogenesisNeural Tube & Heart Beat
Most Vulnerable to Teratogens
Stage 3
Fetal
9 Weeks to Birth
Growth and Finishing
Sensory Development
Age of Viability (~24 weeks)
Environmental Risks: Teratogens
Any environmental agent—biological, chemical, or physical—that causes damage to the developing embryo or fetus.
Warning: Timing is everything.
Categories to Watch
Psychoactive Drugs (Alcohol, Nicotine)
Prescription Drugs (Thalidomide)
Environmental Toxins (Lead, Mercury)
Maternal Diseases (Rubella, Zika)
Severe Maternal Stress
The "Window of Vulnerability"
Germinal
EMBRYONIC (Organogenesis)
FETAL
Major Structural Defects
Physiological Defects /
Conception Week 3 Week 8 Week 24 (Viability) Birth
"In development, order and timing are not just details—they are destiny."
Teratogen Case Studies Worksheet Critical Windows
Teratogen Case Study Analysis
Name:
Date:
Psychology // Developmental Lab #01
Mission Briefing
As developmental psychologists, we must understand how external agents—teratogens —interact with biological stages. Analyze the medical files below. For each case, identify the developmental stage affected, the potential impact based on timing, and the mitigation strategy .
CASE #01
The Virus Variable
Patient History excerpt:
"Patient contracted a high-fever viral infection (Rubella) during Week 5 of pregnancy. At this time, the patient was unaware of the pregnancy. Symptoms lasted for 6 days. Patient is now in Week 12 and concerned about structural heart defects."
1. Developmental Stage & State of Organogenesis:
2. Why is Week 5 particularly high-risk for structural defects?
CASE #02
The Alcohol Effect
Patient History excerpt:
"Patient reports regular binge drinking (4+ drinks per session) throughout the Third Trimester (Week 28-Birth) . Early scans in the first trimester showed normal limb and organ formation."
1. Developmental Stage:
2. Predict the likely impact (Physical vs. Cognitive):
CASE #03
The Thalidomide Tragedy (Historical Context)
Scientific Overview:
In the 1950s, Thalidomide was prescribed for morning sickness. If taken between Days 35 and 50 after the last menstrual period, infants were born with phocomelia (malformation of limbs). If taken after Day 50, no limb defects occurred.
1. Explain the "Critical Period" concept using this data:
Synthesis: The Risk Assessment
Based on your analysis, rank the following factors in order of their impact on the severity of a teratogen's effect. Justify your top choice.
Dose
(Amount of exposure)
Timing
(Developmental stage)
Genetic Susceptibility
(Heredity of mother/fetus)
Justification for "Timing":
Teratogen Analysis Answer Key Teacher Key
Critical Windows Analysis
For Educator Use Only
CASE #01
The Virus Variable (Rubella)
Stage & Organogenesis:
Embryonic Stage (2-8 weeks). This is the peak of organogenesis .
Risk Factors:
Week 5 is a critical period for heart and circulatory system development. Exposure here carries high risk for major structural malformations (e.g., congenital heart disease, blindness, or deafness) because the basic structures are being formed from scratch.
CASE #02
The Alcohol Effect
Stage:
Fetal Stage (9 weeks to Birth).
Predicted Impact:
Since major organ structures (limbs, heart) were formed in the first trimester, the risk shifts toward cognitive and neurological deficits (Fetal Alcohol Spectrum Disorders) and low birth weight . The brain continues to develop rapidly throughout the third trimester; alcohol interferes with neuron migration and connectivity.
CASE #03
Thalidomide Critical Periods
Critical Period Concept:
This case perfectly illustrates that "Timing is Everything." The critical period for limb formation is roughly Days 35-50. Once that window closes (post-Day 50), the limbs are already structurally set, and the teratogen no longer has that specific structural target to disrupt.
Instructional Tip:
Encourage students to move beyond "teratogens are bad" to "teratogens are time-sensitive agents ." The most common misconception is that the fetal stage is the most dangerous because the fetus is "bigger" and "closer to being a baby." Correct this by emphasizing that the Embryonic Stage is actually the most fragile for structural life because that's when the blueprint is being executed.
Neonatal Reflexes Slides The Neonate
Survival Reflexes and Sensory Capabilities
Week 2: Developmental Psych | 11th Grade Psychology
Evolutionary Echoes
Why do babies throw their arms out when startled, or curl their toes when the bottom of their foot is stroked?
"These aren't learned behaviors. They are hard-wired survival programs from our ancient ancestors."
What is a Reflex?
Innate, automatic, and involuntary responses to specific stimuli.
Purpose
Survival, protection, and the foundation for later voluntary movements.
Timeline
Most disappear within 4-6 months as the brain matures (frontal lobe takes control).
Key Neonatal Reflexes
Rooting
Turning head toward touch on cheek. (Finding food source)
Moro (Startle)
Throwing arms out/pulling in when falling/startled. (Clinging to caregiver)
Palmar Grasp
Strong grip on anything placed in palm. (Evolutionary grip)
Babinski
Toes fan out when sole is stroked. (Neurological indicator)
Newborn Sensory Capabilities
Vision
Least developed sense. Vision is blurry (20/600). Preference for high-contrast patterns and faces . Focus is best at 8-12 inches.
Hearing
Functional before birth. Preference for high-pitched voices (Motherese) and complex sounds. Can recognize mother's voice.
Smell & Taste
Highly developed. Preference for sweet tastes (breastmilk). Can identify mother's scent within days of birth.
Reflex Observation Worksheet Survival Wiring
Neonate Reflex Observation Guide
Name:
Date:
Psychology // Developmental Lab #02
Observation Task: Below are clinical descriptions of common newborn behaviors. Identify the reflex being described and analyze its biological or evolutionary purpose. Use your lecture notes and the simulation videos provided in class.
Clinical Description Reflex Name Evolutionary / Survival Purpose "When the infant is held upright and their feet touch a flat surface, they lift one foot and then the other in a rhythmic motion." "A nurse strokes the sole of the baby's foot from heel to toe. The baby's big toe moves upward and the other toes fan out." "The infant is startled by a loud clap. They arch their back, throw back their head, and fling out their arms and legs." "A finger is placed against the side of the infant's mouth. The infant turns their head toward the finger and opens their mouth."
Sensory Simulation Analysis
Based on the "Vision Simulation" shown in class, explain why an infant's 20/600 vision is actually an evolutionary advantage rather than just a deficit. Consider the distance between a baby's face and their caregiver's face during feeding.
Why does a newborn show a strong preference for high-pitched , melodic voices (often called 'Motherese' or 'Parentese') over normal adult conversational tones?
The "Fading" Question:
Most of these reflexes disappear by month 4-6. What does this tell us about the biological maturation of the human brain?
Reflexes Evolutionary Guide Teacher Guide
Evolutionary Origins of Neonatal Behavior
Psychology Unit 1.2
Reflex Observation Key
1. Stepping Reflex Survival Logic
Foundations for voluntary walking; helps baby find the nipple if placed on the mother's stomach (the "Breast Crawl").
2. Babinski Reflex Survival Logic
Mainly used as a clinical diagnostic tool. Presence beyond age 2 suggests neurological damage (damage to the pyramidal tract).
3. Moro Reflex Survival Logic
Ancient primate survival mechanism—if a mother lost her grip while moving through trees, the baby's reflexive "grasp" would help them stay attached.
4. Rooting Reflex Survival Logic
Direct survival: Finding the food source. Complements the sucking reflex.
Vision Paradox
Infant vision (20/600) focuses best at 8-12 inches—the exact distance between a baby's eyes and the mother's eyes during breastfeeding. This "blurry" vision filters out environmental distractions, forcing the baby to bond and focus only on the caregiver.
Auditory Preferences
Newborns prefer high-pitched voices because they are easier to distinguish from low-frequency background noise. This preference ensures the infant remains attuned to human social interaction rather than inanimate sounds.
Psychological Connection:
In psychology, we look for the disappearance of these reflexes. If a 12-month-old still has a Moro reflex, it suggests the frontal lobe isn't maturing enough to inhibit lower-brain signals. This is often an early indicator of cerebral palsy or other motor neuron issues.
Physical Growth Slides Rapid Expansion
Physical Growth and Motor Milestones
Week 3: Developmental Psych | 11th Grade Psychology
The Laws of Development
Cephalocaudal
Growth proceeds from head to tail .
Babies learn to control their head and neck before their torso, and their torso before their legs.
Proximodistal
Growth proceeds from the center outward .
Infants gain control over their trunk and shoulders before their hands and fingers.
Motor Milestone Timeline
2 Months Prone, lifts head
6 Months Sits without support
9 Months Crawling, Pulls to stand
12 Months+ Walking independently
Gross Motor Skills
Involve large muscle groups and whole-body movement.
Rolling over
Crawling
Walking
Fine Motor Skills
Involve small muscle groups , specifically hands and fingers.
Pincer Grasp (9 mos)
Holding a spoon
Stacking blocks
Defining "Normal"
Milestones are averages , not deadlines. Developmental psych uses percentiles to track relative progress.
90%
Window
The age range where 90% of healthy infants achieve the skill.
MATURATION
Nature
Biological growth processes that enable orderly changes in behavior.
EXPERIENCE
Nurture
Tummy time and social stimulation can nudge the timing.
Milestone Mapping Worksheet Milestone Map
Physical and Motor Sequencing
Name:
Date:
Psychology // Developmental Lab #03
Part 1: Biological Directions
A. The Cephalocaudal Trend
Provide a real-world example of how this "head-to-tail" growth manifests in an infant's motor control over the first 6 months.
B. The Proximodistal Trend
Explain why a baby can wave their arms vigorously at a toy but struggle to pick up a small Cheerio until much later.
Part 2: The Motor Timeline
Place the following motor skills in their correct chronological order (1-6) and categorize them as Gross (G) or Fine (F) motor skills.
Uses pincer grasp to pick up small objects
G/F
Lifts head when lying on stomach (prone)
G/F
Walks independently without support
G/F
Rolls over from back to stomach
G/F
Sits alone steadily without falling
G/F
Pulls self up to stand using furniture
G/F
Part 3: Interpreting Norms
"Baby A" sits up at 8 months. The 50th percentile for sitting up is 6 months. "Baby B" walks at 10 months. The 50th percentile for walking is 12 months.
Are either of these babies "delayed"? Why or why not?
Explain how maturation limits the effect of early training (e.g., trying to teach a 4-month-old to walk).
Milestones Answer Key Answer Key
Physical Growth & Milestones
Unit 1.3 Educator Guide
Motor Timeline Sequencing
1
Lifts head when prone (~2-3 mos)
[Gross]
2
Rolls over back to stomach (~4-5 mos)
[Gross]
3
Sits alone steadily (~6-7 mos)
[Gross]
4
Pulls self up to stand (~9 mos)
[Gross]
5
Pincer grasp pick-up (~9-10 mos)
[Fine]
6
Walks independently (~12-15 mos)
[Gross]
Cephalocaudal logic
Control of the head is necessary for balance and visual tracking before the legs can be used for mobility. Students should note that infants can hold their head up weeks/months before they can sit up or crawl.
Maturation vs. Training
Maturation sets the ceiling. You cannot train a 4-month-old to walk because their neural pathways and muscle density have not biologically reached the required threshold. Maturation is the biological "green light" for learning.
Teacher Note on Percentiles:
Neither baby in the example is necessarily "delayed." Developmental psychologists look at trajectories , not single data points. A baby at the 10th percentile for weight who has stayed at the 10th percentile for months is usually fine. A baby who drops from the 90th to the 10th is a medical concern.
Piaget Sensorimotor Slides The Infant Mind
Piaget’s Sensorimotor Stage
Week 4: Developmental Psych | 11th Grade Psychology
The Peek-a-Boo Paradox
Why is 'Peek-a-Boo' hilarious to a six-month-old but boring to a two-year-old?
"For a baby, if they can't see you, you literally cease to exist. You aren't just hiding; you are being resurrected."
"Children are little scientists."
Piaget believed children don't just "soak up" information; they actively construct their understanding of the world through interaction.
Schemas
Mental frameworks used to organize and interpret information.
Adaptation
The process of adjusting schemas (Assimilation vs. Accommodation).
Stage 1: Sensorimotor
Senses + Motor
Thinking happens through physical interaction and observation.
1
Object Permanence
The understanding that objects continue to exist even when they cannot be perceived.
2
A-not-B Error
Searching for an object where it was last found (Location A), even after seeing it moved to a new hiding spot (Location B).
3
Deferred Imitation
Repeating a behavior observed earlier (e.g., pretending to talk on a phone). Shows mental representation.
Circular Reactions
How babies "experiment" to learn cause and effect.
Primary
Repetitive actions centered on the infant's own body (e.g., thumb sucking).
Secondary
Actions aimed at objects outside the body (e.g., shaking a rattle to hear sound).
Tertiary
Intentional variation of actions to see results (e.g., dropping a spoon from different heights).
Cognitive Toy Lab Worksheet The Toy Lab
Applying Piagetian Cognitive Theory
Name:
Date:
Psychology // Developmental Lab #04
Part 1: Cognitive Frameworks
Object Permanence Test
Imagine you are testing a 5-month-old for object permanence. Describe your experiment and the infant's likely reaction.
The A-Not-B Error
Explain why an infant makes the A-not-B error. Is it a failure of memory or a failure of cognitive representation?
Design Brief: The Sensorimotor Specialist
Your mission is to design an educational toy for a specific Piagetian milestone.
Target Milestone:
(e.g., Secondary Circular Reactions, Object Permanence, etc.)
Toy Name:
How it works:
Why it fits this stage:
(Use psychological terms like "scheme" or "circular reaction")
Toy Blueprint / Sketch:
Piaget's Legacy:
Modern research suggests Piaget may have underestimated infant's abilities. Why might a baby show object permanence in a "looking time" study but fail a "reaching" study?
Sensorimotor Substages Teacher Guide Teacher Guide
The 6 Substages of Sensorimotor Development
Unit 1.4 Educator Guide
Substage & Age Key Characteristics Toy Example 1. Simple Reflexes (0-1 mo) Sucking, rooting, grasping. Coordinating sensation and action. Soft pacifier or high-contrast card. 2. Primary Circular (1-4 mos) Reproducing events that happened by chance and were centered on own body (e.g., thumb). Wrist rattles (body focus). 3. Secondary Circular (4-8 mos) Infant becomes more object-oriented. Repeats actions that trigger environmental responses. Musical activity gym or kick-piano. 4. Coordination of SCR (8-12 mos) Intentionality. Using one schema to reach a goal (e.g., moving an obstacle to get a toy). Pop-up toys or hide-and-seek boxes. 5. Tertiary Circular (12-18 mos) "Little Scientist." Active experimentation and trial-and-error variability. Water play sets or shape sorters. 6. Mental Representation (18-24 mos) Internalizing schemas. Insights and symbolic thought. Deferred imitation. Toy kitchen or pretend cell phone.
A-not-B Error Insight
This error usually occurs in Substage 4. It suggests that while the baby has some object permanence, their motor memory is stronger than their mental representation. They search where they were successful before, rather than where they saw it go.
Critique of Piaget
Researchers like Renée Baillargeon found that infants as young as 3 months show "surprise" when objects disappear impossible ways. Piaget's tasks often required complex motor skills (reaching/lifting), which may have hidden the infant's actual cognitive awareness.
Attachment Theory Slides The Social Bond
Attachment Theory and Early Connection
Week 5: Developmental Psych | 11th Grade Psychology
Nature or Nurture?
Is love and attachment a biological drive (like hunger) or a learned behavior (associating food with comfort)?
"We used to think babies loved mothers because they fed them. We were wrong."
Harry Harlow (1950s)
The Experiment
Infant rhesus monkeys were given two "surrogate" mothers:
Wire Mother: Provided milk, no comfort.Cloth Mother: Provided comfort (softness), no milk.
The Result: Contact Comfort
The monkeys spent 17-18 hours a day with the cloth mother , only leaving to get milk from the wire mother.
"Contact comfort is essential for normal social development."
The Strange Situation
The Protocol
A standardized procedure to observe attachment relationships. It involves a series of separations and reunions between infant, mother, and a stranger.
What researchers look for:
Safe Base
Does the infant use the mother as a base to explore?
Separation Anxiety
How does the infant react when the mother leaves?
Stranger Anxiety
How does the infant react to a new person?
REUNION behavior
This is the most critical diagnostic data point.
Attachment Classifications
Secure (60-70%)
Distressed when mom leaves; quickly comforted upon reunion. Uses mom as a safe base.
Avoidant (Insecure)
Indifferent to mom's departure; avoids/ignores mom upon reunion. Often shows physiological stress (high heart rate).
Anxious-Ambivalent
Highly distressed when mom leaves; clings then resists (anger) upon reunion. Not easily comforted.
Disorganized
Confused, erratic, or fearful behavior. Often seen in cases of neglect or abuse.
Attachment Classification Worksheet Bonds of Life
Attachment Style Clinical Analysis
Name:
Date:
Psychology // Developmental Lab #05
Clinical Observation Task
Based on Mary Ainsworth's Strange Situation , read the following three scenarios and identify the Attachment Style . Justify your answer by citing specific infant and caregiver behaviors.
Scenario Alpha
Case Ref: #AS-01
"Leo is 14 months old. In the playroom, he stays close to his mother and refuses to play with the blocks even when she encourages him. When she leaves the room, he screams hysterically. When she returns, he rushes to her to be picked up, but as soon as she lifts him, he begins kicking her and pushing away, though he won't let her put him down."
Classification:
Reasoning (Cite Behaviors):
Scenario Beta
Case Ref: #AS-02
"Maya is 12 months old. She crawls around the room, occasionally looking back at her father and smiling before returning to her toys. When her father leaves, she cries briefly. When he returns, she crawls quickly toward him with her arms up, receives a hug, and then immediately goes back to playing with her teddy bear."
Classification:
Reasoning (Cite Behaviors):
Scenario Gamma
Case Ref: #AS-03
"Toby is 15 months old. He explores the room without checking in with his mother. When she leaves, he doesn't seem to notice or care. When she returns, Toby continues playing with a truck and actually turns his back to her when she tries to get his attention, showing no physical greeting."
Classification:
Reasoning (Cite Behaviors):
Harlow's Synthesis
If a baby is raised in an environment with high "Dose" (food/nourishment) but zero "Contact Comfort" (physical affection), what does Harlow's research predict about their future social-emotional health?
Attachment Long-Term Guide Teacher Guide
Attachment Styles and Long-Term Implications
Unit 1.5 Educator Guide
Case #01: Scenario Alpha Resistant / Anxious-Ambivalent
Evidence: High distress upon separation (anxiety) + "Push-Pull" behavior upon reunion (clinging but kicking). This suggests inconsistent caregiving in the past.
Case #02: Scenario Beta Secure Attachment
Evidence: Uses dad as a "safe base" (smiling/checking in). Briefly upset but easily comforted upon reunion. Immediately returns to exploration.
Case #03: Scenario Gamma Avoidant Attachment
Evidence: Lack of exploration check-in. No distress when mom leaves. Avoidance/ignoring of the caregiver upon reunion.
Internal Working Models (IWM)
Definition
A cognitive framework (schema) comprising mental representations for understanding the world, self, and others. A person’s interaction with others is guided by memories and expectations from their internal model.
Long-Term Connection
Secure infants tend to grow into adults with higher self-esteem and more stable, empathetic romantic relationships. Insecure infants may struggle with intimacy (avoidant) or become overly clingy/fearful of abandonment (resistant).
"Is attachment destiny? Remind students that temperament (nature) and later life experiences (nurture) can shift an attachment style over time. This is called 'Plasticity'."
