Developmental Psychology Overview and Key Concepts

Developmental Psychology

Focuses on how people change across their lifespan, from infancy to old age, in terms of cognition, emotions, behavior, and social interactions.

Development is Lifelong

It occurs from birth to death.

Development is Multidimensional

It includes biological, cognitive, and socio-emotional aspects.

Development is Plastic

It can change based on experiences.

Development is Contextual

It is shaped by culture, society, and history.

Psychosexual Theory

Focuses on how unconscious desires shape development.

Oral Stage

0-1 year - Focus on mouth, sucking, biting.

Anal Stage

1-3 years - Toilet training; control vs. messiness.

Phallic Stage

3-6 years - Oedipus/Electra complex.

Latency Stage

6-12 years - Social skills develop.

Genital Stage

12+ years - Mature sexual relationships form.

Psychosocial Theory

Development occurs through 8 stages of crises.

Trust vs. Mistrust

0-1 year - Secure attachment.

Autonomy vs. Shame

1-3 years - Independence.

Initiative vs. Guilt

3-6 years - Confidence in initiating activities.

Industry vs. Inferiority

6-12 years - Academic & social competence.

Identity vs. Role Confusion

12-18 years - Self-concept formation.

Intimacy vs. Isolation

18-40 years - Close relationships.

Generativity vs. Stagnation

40-65 years - Productivity, guiding the next generation.

Integrity vs. Despair

65+ years - Reflecting on life.

Cognitive Development

Children actively construct knowledge.

Sensorimotor

0-2 years - Object permanence develops.

Preoperational

2-7 years - Egocentrism, symbolic thinking.

Concrete Operational

7-11 years - Logical reasoning, conservation.

Formal Operational

12+ years - Abstract thinking, hypothetical reasoning.

Sociocultural Theory

Zone of Proximal Development (ZPD): Difference between what a child can do alone vs. with help.

Scaffolding

Temporary support given by adults.

Moral Development

Levels of moral reasoning.

Preconventional

0-9 years - Obedience & personal gain.

Conventional

9-16 years - Social norms & law/order.

Postconventional

16+ years - Ethics, human rights.

Hypothesis Testing

Process of making inferences about populations based on sample data.

Null Hypothesis (H₀)

No difference/effect exists.

Alternative Hypothesis (H₁)

A significant difference/effect exists.

Type I Error

Rejecting a true null hypothesis (false positive).

Type II Error

Failing to reject a false null hypothesis (false negative).

Random Sampling

Equal chance for every participant.

Stratified Sampling

Dividing into groups and selecting proportionally.

Convenience Sampling

Selecting participants based on availability (least scientific).

Mean

Arithmetic average (sensitive to outliers).

Median

Middle value (best for skewed data).

Mode

Most frequently occurring value.

Standard Deviation

Measures spread of data around the mean.

Hippocampus

Memory formation.

Amygdala

Emotion regulation, especially fear and aggression.

Hypothalamus

Controls hunger, thirst, body temperature, and hormones.

Cerebellum

Coordination and balance.

Frontal Lobe

Decision-making, problem-solving, voluntary movement.

Dopamine

Linked to movement (Parkinson's) and reward (schizophrenia, addiction).

Serotonin

Mood regulation (low levels linked to depression).

Acetylcholine

Muscle contraction and memory (deficit leads to Alzheimer's).

GABA

Inhibitory neurotransmitter (deficit causes anxiety).

Test-Retest Reliability

Stability of scores over time.

Inter-Rater Reliability

Agreement between different observers.

Internal Consistency

Extent to which test items measure the same construct.

Content Validity

Test covers all aspects of a concept.

Construct Validity

Test actually measures what it intends to measure.

Criterion Validity

Test correlates with an external measure of the concept.

Standardization

Process of administering tests under uniform conditions.

Schizophrenia

Hallucinations, delusions, disorganized thinking (linked to dopamine imbalance).

Major Depressive Disorder

Persistent sadness, loss of interest, fatigue (low serotonin).

Generalized Anxiety Disorder

Excessive, uncontrollable worry for 6+ months.

Obsessive-Compulsive Disorder (OCD)

Unwanted thoughts (obsessions) and repetitive behaviors (compulsions).

Psychoanalysis

Unconscious conflicts and childhood experiences.

Behavior Therapy

Uses conditioning (e.g., exposure therapy for phobias).

Cognitive Therapy

Focuses on changing negative thought patterns.

Humanistic Therapy

Client-centered approach emphasizing self-growth.