psyc1030 quiz 3

Developmental Psychology

• Psychology has various subfields, including clinical, social, and developmental psychology.
• Developmental psychology studies how people grow, change, and adapt throughout their lives, from infancy to late adulthood.
• It integrates scientific research, psychological theory, and observational methods to understand transformations in behavior and emotions over time.

What Developmental Psychology Studies:

• Physical Development: Growth patterns, motor skills, puberty, and aging processes.
• Cognitive Development: Changes in thinking, problem-solving, language acquisition, and memory from infancy to older adulthood.
• Social and Emotional Development: Attachment and relationships, self-concept, emotional regulation, moral reasoning, and personality formation across different life stages.

Typical Questions in Developmental Psychology:

• How do genetic factors and the environment (nature vs. nurture) interact to shape development?
• Why do children form certain attachment styles, and how do these styles impact later relationships?
• What drives cognitive milestones (e.g., learning to speak, read, reason)?
• How do societal and cultural contexts influence growth and identity formation?
• What factors contribute to resilience or vulnerability across different life stages?

Why Study Developmental Psychology:

• Insight into Human Growth: Understand how people evolve physically, cognitively, and socially across the lifespan.
• Improving Quality of Life: Inform educational practices, parenting approaches, healthcare decisions, and social policies.
• Broader Impact: Promote healthier childhood development, support adolescents through transitions, and improve care for older adults.
• Connection to Other Fields: Overlaps with clinical psychology (e.g., diagnosing developmental disorders) and social psychology (e.g., peer influence in adolescence).

Infancy

• Infancy spans the first 2 years of life.
• It's a period of rapid development from a primitive state.
• Weight triples and length increases by 50%.
• The brain grows to 80% of its adult volume, and the cortex doubles in surface area.
• Coordinated reach, locomotion, and first words emerge.

Why Study Infancy:

• Foundations of Later Cognition, Personality, and Health: Expressive vocabulary measured between 16-30 months significantly predicts grade-9 exam scores at age 15, even after controlling for SES and other early-life factors.
• Period of Maximal Neural and Behavioral Plasticity: Deaf infants receiving cochlear implants before 12 months develop speech intelligibility and language scores indistinguishable from normal-hearing peers. Implantations after age two yield substantially poorer outcomes.
• Practical Relevance: Parenting, clinical screening, and public policy.
  • Kangaroo Mother Care (KMC): Continuous skin-to-skin contact begun immediately after birth reduces mortality and accelerates neurodevelopment in pre-term and low-birth-weight infants. Many countries now mandate KMC units in neonatal wards, saving an estimated 150,000+ infant lives annually.

Key Questions about Infancy:

1. How prepared are newborns at the moment of birth?
2. How do genes and experience weave together across the first two years?
3. How do scientists infer mental life from creatures who cannot yet speak?

Infancy - Historical Perspectives

Nature (Plato):

• Everything that the adult will become is already present at birth.
• Capabilities, skills, and personality are genetically encoded.
• Development is primarily maturation.

Nurture (John Locke and William James):

• The infant is a blank slate bombarded with sensory information.
• Development involves making sense of this information by forming associations.

Nature AND Nurture:

• Gene-Environment Interactions: The impact of genes on behavior depends on the environment in which the behavior develops.
• Nature via Nurture: Genetic predispositions drive individuals to seek or create particular environments that then enhance the behavior.
• Gene Expression: Genes turn on in response to specific environmental events.
• Epigenetics: Genes dynamically respond moment to moment to environmental conditions.

Sensory Systems

• Evolution equips neonates for immediate survival tasks.
• All 5 sensory systems are functional but unevenly mature.
• Vision is least developed; touch and smell are most advanced.

Early Biases Tune Infants to Caregivers and Nutrition:

• Newborns track top-heavy, face-like patterns.
• Sucrose elicits relaxed facial expressions and ingestion; bitter tastes trigger aversive "gape" responses.

Vision

• Newborn acuity = 20/500 (WHO "profound impairment").
• Fixed focal distance = 20 cm (stiff lens), optimal for face-to-face bonding.
• Accommodation begins to emerge around 8-10 weeks; adult-like dynamic focusing is reached by 6-7 months.
• Adult-level acuity and binocular depth are achieved by approximately 8 months.
• Synaptic density in the primary visual cortex overproduces to approximately 150% of adult levels by 4-8 months.
• Redundant connections allow for experience-driven refinement and later rapid pruning as crawling begins.

Hearing

• The cochlea matures by 24 gestational weeks; the womb filters high frequencies.
• Late-gestation EEG shows rhythm encoding of speech-like patterns.
• Newborns preferentially suck to hear their mother's voice and native prosody.
• Categorical Speech Perception: Present at birth (general), but by 8-12 months, sensitivity narrows to the native language only.
• Music: Preference for consonant over dissonant intervals by 3 months.
• Sound localization accurate to ±6° by 5 months.
• Eimas et al. (1971): Investigated categorical speech perception in 1- and 4-month-old infants.
  • Infants were conditioned to respond to the syllable "pa" (increased sucking).
  • Pairs of "ba" and "pa" were presented with varying intervals (0ms to 80ms).
  • No change in sucking was observed at short intervals.
  • A clear increase in sucking occurred at the categorical boundary (20ms – 40ms), similar to adult speech perception.

Touch

• Significant development before birth.
• Dense mechanoreceptors: Cutaneous receptors first appear along the lips at 7-8 gestational weeks and cover the entire body by ~20 weeks.
• Reflexes triggered by tactile cues (rooting, grasp).
• Newborns can detect object shape and texture by mouthing.
• Feel pain but descending inhibition is immature, requiring analgesia.
• Birth: A significant change from fluid to air/clothing/skin requires rapid recalibration of circuits in the first weeks.
• By 9 months, touch integrates with vision and proprioception (body representation).

Taste and Smell

• Critical for feeding and protection.
• Essentially mature at birth.

Taste:

• Innate preference for sweet tastes (energy) and aversion to bitter tastes (toxins).
• Fetal and breast-milk exposure to flavors (e.g., carrot, garlic) leads infants to later accept those foods more readily.

Smell:

• Day-1 orientation to maternal breast-pad odor.
• By 1 month, infants distinguish their mother's T-shirt from a stranger's.
• 2024 fMRI study: Maternal scent dampens the infant's amygdala response to threat faces.

Timelines

Early Motor Programs - Reflexes

• Present at or within days of birth --> "built-in" motor circuits.
• Reflexes solve immediate survival problems while the cortex is immature.
  • Feeding: Rooting and sucking.
  • Protection: Moro (startle) reflex.
  • Attachment: Palmer grasp reflex.
• Critical: These reflexes should fade within about 4 months to be replaced by voluntary controlled movement.

Early Motor Programs - Voluntary

• Head control = 6 weeks (prone life), full antigravity by 3 months.
• Goal-directed reach emerges at 3-4 months as vision-hand mapping stabilizes.
• Rolling --> crawling --> cruising sequence between 4-10 months, but cultural variation is large.

Emotion & Temperament

• Birth - 2 months: Two global states: distress/excitement vs. contentment.
• 2-4 months: Discrete joy and surprise appear.
• 5-7 months: Anger, fear, and sadness become identifiable in facial-action coding.
• 9-12 months: Social-referencing to caregiver's emotional cues.
• Early expressions are hard-wired yet rapidly shaped by caregiver mirroring.
• Temperament: Biologically-based individual differences in reactivity & self-regulation.
• Temperament captures early-life individuality, observable long before personality traits can be measured.
• Thomas & Chess Axes: Biological regularity, Hedonic tone, and Approach / withdrawal to novelty.
  • Easy ≈ 40% (regular, positive, approach).
  • Difficult ≈ 10% (irregular, negative, withdrawal).
  • Slow-to-warm ≈ 15% (low activity, mild negativity, gradual approach).
• Overall infancy-to-adulthood correlation modest, but extreme temperaments often persist.
• Caregiving and later self-control can amplify or mute early tendencies.
  • Behavioral inhibition at 4 months --> introverted, anxiety-prone adults.
  • “Under-controlled” 3-year-olds had the poorest health & finances at 45 years.
• Temperament sets initial parameters; the environment fine-tunes emotional style.
• Optimal development occurs when caregiver response matches child temperament.
  • Difficult babies need consistent, sensitive routines.
  • Easy babies still need stimulation.
  • Parent training is essential.

Studying Babies

• No instructions, no verbal reports.
• Must rely on natural behaviors and reflexes.
• Measures: Looking, sucking, and reaching.
• Changes in these behaviors correlate with things of interest; thoughts are inferred from actions.
• Indirect inference is sensitive to fatigue/state changes and requires converging methods for firm conclusions.

Preferential Looking

• Fantz (1960s): Infants look longer at face-like, high-contrast patterns.
• Infant reclines on a parent’s lap or crib mattress.
• A display board shows Stimulus A on one side and Stimulus B on the other, each positioned at the optimum focal distance (~20 cm).
• Eye-tracking monitors gaze.
• Positions are switched to control for side bias.
• 0-48-hour newborns: High-contrast schematic face (40%) vs. scrambled face (15%).

Physiological Additions

• Confirm and extend behavioral findings.
  • Heart-rate deceleration: Sustained attention.
  • Pupil dilation / skin conductance: Arousal.
  • EEG/ERP & fNIRS: Cortical localization.

Key Takeaways

1. Newborns are prepared yet plastic, equipped with adaptive biases while remaining exquisitely moldable.
2. Development is "nature via nurture": Genes provide ranges; environments tune trajectories.
3. Methodological ingenuity drives discovery: How we ask dictates what we can know.

Social Development

• Describe the preferences and abilities of young infants
• Understand how infants learn from others and distinguish the self from others
• Describe when young children start to display helping behaviours, and what these behaviours are.
• Explain what theory of mind is, and why it is useful for children to have a theory of mind.

Newborn Preferences

• Newborns have preferences that drive what they learn.
• Social learning involves paying attention to faces.
• Goren et al. (1975): Found infants prefer face-like stimuli.
• Infants prefer human speech over artificial sounds, especially maternal language sounds and accents, which aids in fitting into their community.

Sensitivity to Emotional Cues

• Within the first six months, infants develop a sensitivity to emotional cues.
• Important in social situations.
• Field et al. (1982): Infants as young as 36 hours old could differentiate positive (happy) from negative (sad) emotions, as well as positive/negative expressions from surprised expressions.
• Around five months, infants prefer hearing the sound that matches the emotion of the face (Walker-Andrews, 1997), such as a laughing sound with a happy face.
  • They can match acoustic elements with visual cues, especially for familiar people (e.g., their mother).
• Their ability to generalize increases across the first year of life.

Responding to Emotions

• Infants can recognize different emotional cues and use this ability to respond appropriately.
• The first month: smiles are usually due to being full or having had a good sleep.
• Around three months: infants smile in response to social cues (social smile).
• Around six months: they're tuned into familiar people and show more smiling/laughing to familiar people (e.g., mother) than strangers.
• Infants are attuned to mothers’ expressions.
• Contagious Crying: When one infant cries, others cry too (3-6 months).
  • Argument 1: Due to basic empathy (feeling what others feel).
  • Argument 2: Infants are just hyper-reactive (freaked out because someone else is freaked out).
  • May be basic empathy or emotional arousal.
• Infants produce emotional responses, enabling them to be active in social interactions. Still Face Experiment (Tronick et al., 1978):
  • Phase 1: Normal play session between mother and infant.
  • Phase 2: Mother switches to a neutral expression (“still face”), causing distress for the infant as it’s not normal. The infant tries to regain the mother’s attention, realizing that social interaction involves two-way communication.
  • Phase 3: Mother changes back to happy expressions; infants happily interact again as if nothing happened, especially those securely attached.
• This experiment demonstrates that infants are actively involved in social interactions.

Joint Attention and Social Referencing

• Infants love to learn from around six months to around 18 months.
• They seek information through joint attention, using gaze and pointing to share focus and learn object names.
• Social Referencing: Infants look at their mothers to see how she is reacting.
• Infants develop social referencing at around 10 to 12 months of age.

Visual Cliff Paradigm:

• Infants are tested to see if they have developed depth perception.

Scaffolding

• Between 6 and 18 months, mothers play a vital role in scaffolding infants' understanding of mental states.
  • Scaffolding is building an infant’s knowledge through teaching them something slightly more difficult than what they already know.
  • Mental states include desires, thoughts, beliefs, and knowledge.
• Mothers help infants by discussing their mental states, particularly their desires (e.g., "Do you want that apple?"), more than their thoughts or beliefs.
• It’s crucial that mothers talk about the infant’s own mental states (e.g., "Do YOU want that apple?").

Sense of