Human Development

Developmental Psychology

• Studies age-related behavioral & mental changes from conception → death.

• Focus on growth AND decline; examines biological (nature), cognitive, enviornmental and social experiences (nurture).

• Key construct: Resilience

  • Ability to recover from or adapt to difficult times.

Physical Development

Prenatal Stages

• Germinal: conception → uterine implantation (≈2 weeks).

• Embryonic: implantation → week 8.

• Fetal: week 8 → birth.

Conception Basics

• Sperm + egg = zygote (fertilized cell carrying combined genetic code).

Brain Development Timeline

• 3\;\text{wk}: forebrain, midbrain, hindbrain emerge; spinal cord forms.

• 11\;\text{wk}: structures enlarge; cortical differentiation begins.

• Birth: hindbrain & midbrain largely matured; forebrain still rapidly proliferating.

Early Childhood (0-6 yr)

• Brain: synaptic growth and pruning; myelination

• Motor: maturation sets sequence of development

• Sensory/Perceptual: development occurs through brain and body maturation and learning

Adolescence

Adolescent Brain

• early development: limbic system (emotions)

• later development: prefrontal cortex (reasoning and decision-making, risk taking)

The Aging Brain

some new cells grow in hippocampus and olfactory bulb

surviving or healthy neurons pick up the slack for disabled neighbors

reduced lateralization- both hemispheres used more equally

Motor Development

maturation are changes that occur primarily because of passage of time

• maturation takes place in the body and cerebellum

• physical training generally cannot change the timing

Physical Development in Adolescence

• Puberty: is the time of sexual maturation and during puberty, increased sex hormones lead to → primary & secondary sexual characteristics and some changes in mood and behvaior

Adulthood

• Early (mid-20s): biological peak—muscle strength, cardiac output, reaction time, sensory sensitivity.

• Middle Age

  • Women: Menopause (late 40s–early 50s).

  • General: lose height, gain weight.

• Late Adulthood

  • Primary aging: inevitable biological change.

  • Secondary aging: lifestyle-controllable (disease, disuse, neglect).

Cognitive Development (Piaget)

• Children actively construct knowledge via schemas (mental frameworks).

• Two adaptive processes:

  • Assimilation: fit new info into existing schema.

  • e.g., toddler calls a cat “dog” because of 4-legged schema.

  • Accommodation: adjusting old schemas or developing new ones to better fit with new information (distinguish cat vs dog varieties).

Stage 1 – Sensorimotor (0\rightarrow2 yr)

• Understanding of the world through senses & actions.

• Object permanence emerges → things exist even when unseen.

Stage 2 – Preoperational (2\rightarrow7 yr)

• Symbolic thought; language explosion.

• Deficits (“hallmarks”):

  • Lack of conservation

  • Animism (objects are alive).

  • Egocentrism- tendency of a child to only think from own point of view (do you have a brother? Yes,jim. does jim have a brother? no)

Stage 3 – Concrete Operational (7\rightarrow11 yr)

• Perform logical operations on concrete objects/events

• breakfree from hallmarks of prior stage

Stage 4 – Formal Operational (11+ yr → adulthood)

• Think abstractly; hypothetical-deductive reasoning (draw conclusions from available information).

Executive Function

• complex cognitive processes: planning, inhibition, problem-solving.

• Theory of mind: understanding others dont think, feel, or believe like you

Adult Cognitive Trends

• Early adulthood: idealism → pragmatic realism.

• Middle adulthood: intellectual skills, memory

• Late adulthood: slower processing & retrieval; but wisdom may grow

Temperament & Attachment

Temperament

individuals behavioral style or characteristic way of responding

• Easy 40\% – cheerful, relaxed, agreeable

• Difficult 10\% – irritable, moody, over-reactive

• Slow-to-warm 15\% – shy, withdrawn, takes time to adjust

Attachment Styles (Ainsworth – Strange Situation)

• Secure: explores but checks back occasionally

• Avoidant / Dismissive: treats mother & stranger similarly; little distress.

• Anxious / Ambivalent / Pre-occupied: clingy pre-separation, intense distress

• Harlow’s Rhesus monkey experiment: infants chose cloth mother over wire-food mother

Socio-Emotional Development (Erikson)

• Eight psychosocial crises; resolution → competence or weakness.

• Emerging Adulthood (18–25 yr): prolonged transition marked by identity exploration, instability, self-focus, feeling "in-between," optimism.

Parenting Styles (Baumrind)

• Authoritative: high warmth, moderate control; democratic → competent, friendly children.

• Authoritarian: low warmth, high control; rigid → conflicted, moody children.

• Permissive/Indulgent: high warmth, low control; lenient → impulsive, spoiled behavior.

• Neglectful/Uninvolved: low warmth & control → low self-esteem, conduct & academic problems.

Gender & Identity

• Gender: psychosocial experience of being male/female/both/neither; encompasses cognition, emotion & biology.

• Gender identity: inner sense of gender; distinct from sexual orientation & outward expression.

Moral Development (Kohlberg)

• Assessed via moral dilemmas (e.g., Heinz steals drug). Reasoning why determines stage.

• Current research: prosocial behavior fostered by supportive parenting, peers, culture; conscience forms by \approx3\;\text{yr} via emotionally rich parent-child dialogue.