Developmental Psychology Overview

Developmental Psychology

• Developmental psychology studies how people change physically, cognitively, socially, and emotionally from infancy to old age.
• Development can be qualitative (changes from one stage to another) or quantitative (continuous and gradual changes).
• Nature (genetics and biology) and nurture (environment and culture) both influence development.
• Key challenges for developmental research include selecting appropriate measures based on age and abilities and choosing the right research design.

Research Designs

• Cross-sectional: Compares groups of different ages at the same time. Advantages: understanding abilities at different ages and comparing groups close in age; Disadvantages: cohort effect, less useful for dramatic age differences.
• Longitudinal: Studies the same group of people over a long period. Advantages: confidence in observing changes over time; Disadvantages: time-consuming, costly, attrition (participants dropping out), and often only examines one generation.
• Sequential: Combines cross-sectional and longitudinal approaches. Advantages: high confidence in observed changes, better generalization to other cohorts; Disadvantages: costly, time-intensive.

Prenatal Development

• Germinal stage: Conception to two weeks; zygote (fertilized egg) forms; blastocyst (hollow ball of cells).
• Embryonic stage: Two to eight weeks; embryo develops. Placenta forms to nourish the fetus.
• Fetal stage: Ninth week to birth; fetus grows and matures; significant development of brain and body systems; responsiveness to light around week 26 and develops fully by 27 weeks.

Brain Development

• Neural tube: early structure that forms the brain and spinal cord.
• Neurons & glia: fundamental cells the neural tube develops into.
• Neural migration: glia cells create guide wires for neurons.
• Neural proliferation: creation of new synaptic connections.
• Synaptic pruning: elimination of unused neural connections.
• Myelination: insulation of axons for faster signal transmission.
• Maturation occurs differently in different brain areas (sensory, motor, language, frontal lobes).

Developmental Disorders

• Down syndrome: extra copy of chromosome 21, leading to intellectual and physical disabilities.
• Teratogens: environmental agents that can harm a developing fetus (e.g., alcohol, tobacco).
• Fetal Alcohol Syndrome: developmental disorder from prenatal alcohol exposure, affecting intellectual abilities, attention, physical growth, and activity level.

Infancy

• Newborn reflexes: automatic motor responses to sensory stimuli, including preferences for tastes, smells, voices, and "face-like" stimuli. Newborns appear to imitate facial expressions, though motivation might be more about interest and arousal.
• Habituation/dishabituation: decreased/increased response to repeated/new stimuli, measuring infants' learning.
• Motor development: follows cephalocaudal (head-to-toe) and proximodistal (center-outward) trends.

Cognitive Development (Piaget)

• Schemas: Mental models to understand experiences.
• Assimilation: Using existing schemas to interpret new experiences.
• Accommodation: Modifying schemas to incorporate new experiences.
• Sensorimotor stage: (birth-2 years) knowledge through senses and actions, object permanence is important.
• Preoperational stage: (2-7 years) symbolic representation emerges; egocentrism is prevalent.
• Concrete operational stage: (7-12 years) logical thinking about concrete objects. Conservation abilities develop.
• Formal operational stage: (12 years and up) abstract and hypothetical reasoning.

Attachment Theory

• Attachment: enduring emotional bond between infant and caregiver. Imprinting is a specific type of early attachment.
• Attachment styles: secure, insecure-avoidant, insecure-resistant (ambivalent).
• Temperament: stable individual differences in emotional reactivity, activity, attention, and regulation; influence attachment styles.
• Parenting styles: influential on attachment; authoritative, authoritarian, permissive, and disengaged parenting styles.

Social Psychology

• Social psychology examines how social contexts influence thoughts, feelings, and behaviors.
• Attribution: explaining behavior (fundamental attribution error, self-serving bias).
• Attitudes: evaluations of stimuli (explicit and implicit).
• Persuasion: Elaboration Likelihood Model (Central & Peripheral Routes).
• Compliance Techniques: Foot-in-the-door, door-in-the-face.
• Cognitive Dissonance: discomfort from inconsistencies in thoughts/actions; changed attitudes to reduce.
• Social norms: shared patterns of actions, beliefs, and preferences.
• Conformity: Mimicking or adopting others' behaviors; informational & normative social influences.
• Group dynamics: group polarization, social loafing, groupthink, deindividuation, social facilitation.