Developmental psychology studies how human behavior changes over time, from infancy through adulthood. Key theorists include Piaget, who described stages of cognitive development from sensorimotor to formal operations, and Erikson, who proposed psychosocial stages of development. Research employs cross-sectional and longitudinal methodologies to understand maturation, the influence of environment and heredity, and disorders like autism across the lifespan.

1. Developmental Psychology

2. Development
• Developmental psychology
o Studies maturation of human behavior over time
o Recent shift from adolescent studies to lifespan
research
• Maturation
o Individual growth/development biologically based
o What is the interaction between hereditary and
environment?

3. Development
• Infancy
o Newborns have simple adaptive reflexes
• Rooting reflex
• Tonic neck reflex
• Palmar grasp reflex
• Plantar reflex
o Motor reflexes develop during later critical periods
• Smiling, turning head, rolling over, crawling, walking

5. Piaget
• Assimilation
o Occurs when new experiences are incorporated into
existing schema
• Accommodation
o Occurs by changing existing schemas to accommodate
new information
o Can be a more difficult process

6. Piaget
• Stages of Cognitive Development
o Cognitive schemas
o Emphasized how children’s mental abilities progress
qualitatively on a fixed sequence of stages
o At each stage of development, children use a distinct
type of thought to guide thinking

7. Piaget
• Sensorimotor Stage (0 - 2 years)
o Earliest stage
o Child is completely egocentric
o No sense that objects are separate from themselves
o Learning occurs through use of hands and mouth
o Object permanence?
• The understanding an object continues to exist even
when you can't see it or touch it

8. Piaget
• Preoperational (2-7 years)
o Conserving number, length, amount, weight, and
volume is difficult
o Perceptual impression chosen over logic
o Putting self in another person’s place is difficult
o Contradicting themselves is not a problem
o Language acquisition and symbolic thinking

9. Piaget
• Concrete Operational (7-11 years)
o Thinking can be reversed and a sequence of changes can
be held in the mind
o
‘
Awareness of other people’s viewpoints
o Appearance of systematic and logical reasoning

11. Piaget
• Formal Operational (12+ years)
o Ability to recombine groups into fewer or broader
categories develops
o Defining concepts using other abstract concepts is
possible
o Can use analogies to understand concepts
o Independent, abstract thinking
o Can think about thinking

12. Development
• Critical periods
o Genetically pre-determined maturation phases
o Periods of extremely high sensitivity to stimuli from
environment that shape future development
o Victor of Aveyron/L'Enfant Sauvage (1799)
o Calrson et al. (1987) visual deprivation in monkeys

13. Development
• Imprinting
o Duckling studies (Lorenz)
• Hatching appears to be a critical period for ducklings
• 1st large moving object they see becomes imprinted as the
mother
o Early animal imprinting with humans = good pets
o Harlow’s rhesus monkeys

15. Development
• Parenting styles
o Authoritative
o Authoritarian
o Permissive
o Uninvolved

16. Kohlberg’s Levels of Moral Development
• Preconventional morality
o Follow moral rules to avoid punishment or obtain rewards
• Conventional morality
o Define what is right by the standards learned from others
o Internal belief in the moral rules learned
• Postconventional morality
o Use of self-defined moral principles that may not match
conventional moral beliefs
o Morals defined by one’s culture may be viewed as a social
contract and potentially fallible

17. Kohlberg’s Moral Development Theory

18. Erikson’s Psychosocial Stages of Development

19. Methodology
• Cross-sectional designs
o Studying separate groups at the same time
o Sample of 8th, 10th, and 12th graders
o Be aware of potential confounds
• Longitudinal designs
o Studying the same individuals/group over time
o Sample of 8th graders tested again in 10th and 12th grade
o Be aware of attrition

20. Disorders
• Autism
o Extreme social withdrawal + impaired verbal/nonverbal
communication skills
o Physical condition linked to abnormal chemistry in brain
o Asperger syndrome
• Milder form of autism
• Delayed motor development milestones
• Intense preoccupation w/narrow area of interest (phone books)

21. Death and Grief
• 5 Stages of Grief (Kubler-Ross, 1977)
o Denial
o Bargaining/rationalization
o Anger
o Grief/sadness
o Acceptance