Psychology is defined as the science of behavior and mental processes. It has evolved from ancient Greek and modern philosophical roots and aims to understand the human mind through empirical research and observation. The major branches of psychology include clinical, developmental, industrial/organizational, social, and cognitive/experimental psychology. Psychology follows the scientific method and can be divided into basic research and applied fields like clinical and industrial psychology. Its history involves key figures like Wundt, Watson, Freud, Rogers, and developments like behaviorism and the cognitive revolution.

1. Psychology: Definitions & History

2. Psychology
 Definitions
o From Greek word “psyche” to “talk about the self”
o The science of behavior and mental processes research
to obtain knowledge about the human mind
o Explains mental functions and underlying processes
• What is behavior?

3. Branches of Psychology
 Clinical
o Assessment and treatment individuals with chronic mental
disorders or psychological crises (OCD, PTSD, grief)
o Can focus on specific group to treat (autistic children), or
more generally (addiction, relationship issues, and anxiety)
o Licensing and APA-sanctioned internship required to
practice
 Developmental
o Study of how we develop intellectually, emotionally, and
how we change and grow over the lifespan

4. Branches of Psychology
 Industrial/Organizational
o Explore relationships between individuals and their work
environment
o Leadership trust, increase productivity, involved in
staffing/personnel selection
 Social
o Individual and group behavior, attitudes, addiction,
persuasion, gender issues, self-esteem, motivation, personality,
market research, etc.
 Cognitive/Experimental
o Study learning, memory, sensation/perception

5. Psychology
• Scientific psychology = Empirical research studies
o “Basic research” to build psychology’s knowledge base
o Cognitive, developmental, abnormal, social psychology
• Applied psychology = “Real world” psychology
o Clinical, sport, or industrial/organizational psychology,
market research…

6. Psychiatry vs. Psychotherapy vs. Psychoanalysis?

7. Clinical Psychology
• Psychiatry = branch of medicine concerned with mental
disorders; psychiatrists are medical doctors
who prescribe medication
• Psychotherapy = a form of treatment emphasizing
communication
• Psychoanalysis = Freudian theories/techniques
emphasizing unconscious conflict

8. Psychology
 What makes psychology scientific?
• Like all science, psychology follows the empirical method
• Data + theory = knowledge
• Empiricism = Observation, objectivity, precision,
experimentation, etc.

9. Psychology
 History
• Origins of psychology are rooted in philosophy
o Free will vs. Determinism
• Plato vs. Aristotle (Ancient Greece)
o Plato – Personality/characteristics inherited
o Aristotle – Nothing in the mind that does not originate from
external world via the senses
• Locke vs. Descartes (1600s)
o Locke – Mind blank slate at birth; knowledge comes via senses
o Descartes – Knowledge not dependent on sense experiences

10. History
• James (1875)
o American physician
o Wrote classic psychological text Principles of Psychology
• Wundt (1879)
o German physician
o Empiricism: science flourishes via observation/experimentation
• Watson (1900s)
o Founder of Behaviorist movement
o Behaviorism: Ignore mental states and focus only on what
is observable (behavior); the mind as a “black box”

11. History
• Psychoanalysis
o Freud (1890s)
• Emphasized unconscious drives (sex and aggression) as root of all
behavior
• Humanistic Psychology
o Rogers/Maslow (1950s-1960s)
• Emphasized free will; the ‘great reservoir’ of human potential
• Focused on optimal development rather than negatives
• Cognitive Revolution (1960s)
o Focused on perception, processing, retrieval of information, how memory
works, decision making, “the mind as a computer”, human cognition

12. Maslow’s Hierarchy of Needs