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Developmental Psychology Study Guide

Themes in Development

1. Nature vs. Nurture

   • Nature: Biological influences (genes, DNA).

   • Nurture: Environmental influences (family, culture, education).

2. Continuity vs. Discontinuous

   • Is development gradual (continuous) or does it occur in stages (discontinuous)?

3. Stability vs. Change

   • Do early traits remain stable, or do they change over time?

Research Methods

• Cross-Sectional Studies: Data collected from different individuals at a single point in time.

• Longitudinal Studies: The same individuals are examined over time to track changes.

Stages of Development

Prenatal Development

• Teratogens: Harmful agents like drugs, alcohol, and viruses that can affect fetal development.

• Fetal Alcohol Syndrome (FAS): Caused by alcohol consumption during pregnancy, leading to physical and cognitive impairments.

• Critical/Sensitive Period: A time when the brain is highly receptive to learning experiences (e.g., language acquisition, attachment formation).

Infancy and Early Childhood (0-6 years)

• Newborn Reflexes:

  • Rooting Reflex: Turning head toward a touch on the cheek.

  • Grasping Reflex: Automatic grasping of objects placed in the palm.

  • Startle Reflex: Spreading arms and legs in response to sudden movement or noise.

• Visual Cliff Experiment: Tests infants’ depth perception.

• Habituation: Decreased response to repeated stimuli.

• Maturation: Biological growth processes that occur in a predictable sequence.

• Fine Motor Skills: Small muscle movements (e.g., grasping, writing).

• Gross Motor Skills: Large muscle movements (e.g., walking, jumping).

Middle Childhood (6-12 years)

• Increased cognitive development, problem-solving, and social skills.

• Improved motor coordination.

• Learning academic and social rules.

Adolescence (12-18 years)

• Puberty: Physical maturation with hormonal changes.

• Adolescent Growth Spurt: Rapid height and weight changes.

• Menarche: First menstrual period in females.

• Spermarche: First ejaculation in males.

• Primary vs. Secondary Sex Characteristics:

  • Primary: Directly related to reproduction.

  • Secondary: Distinguishing traits like deeper voices and breast development.

• Brain Development:

  • Pruning: Removing unused neural connections.

  • Prefrontal Cortex Development: Improves decision-making but lags behind the limbic system, leading to emotional impulsivity.

  • Risk-Taking: Teen brains are wired for immediate rewards.

Early Adulthood (20s-30s)

• Peak physical performance.

• Cognitive and emotional stability.

• Establishing independence, relationships, and careers.

Middle Adulthood (40s-65 years)

• Physical Changes:

  • Gradual decline in strength, flexibility, and reaction time.

  • Decline in fertility (menopause in women, reduced sperm count in men).

• Cognitive and Emotional Development:

  • Peak problem-solving abilities.

  • Increased focus on family and career.

Older Adulthood (65+ years)

• Physical Decline:

  • Reduced muscle mass, slower mobility.

  • Vision and hearing loss.

  • Weaker immune system (but stronger immunity to common colds due to built-up antibodies).

• Cognitive Changes:

  • Brain shrinkage, slower processing speeds.

  • Increased impulsivity due to prefrontal cortex atrophy.

  • Risk of memory-related diseases (e.g., Alzheimer’s).

• The Role of Exercise:

  • Improves cognitive function and slows aging.

  • Promotes neurogenesis (growth of new brain cells).

Key Psychological Experiments and Concepts

• Imprinting: Some animals form attachments immediately after birth, while human bonding is more complex.

• Visual Cliff Apparatus: Demonstrates infant depth perception.

• Habituation: Learning through repeated exposure to stimuli.

• Maturation: Predictable physical and cognitive growth patterns.

Final Thoughts

Development is influenced by a mix of biological, psychological, and environmental factors. While some aspects of personality and traits remain stable, others evolve over time. Understanding these stages helps us comprehend human growth and behavior throughout life.