Psychological Science: Historical Roots, Key Theories, and Research Design
Cognitive Biases in Thinking
- Confirmation bias: Ignoring evidence that opposes our beliefs (e.g., on vaccines).
- Failing to accurately judge source credibility (e.g., celebrity endorsements).
- Misunderstanding or not using statistics (e.g., gambler’s fallacy).
Scientific Foundations of Psychology (Antiquity–18th Century)
Psychology originated in philosophy, with roots in epistemology (the study of how we gain knowledge).
Plato: Founder of Rationalism
- Advocated rational analysis to understand the world rather than empirical observation.
- Believed we are born with innate knowledge, which we must find a way to access.
- Suggested mathematics can predict the world even before observation.
Aristotle: Founder of Empiricism
- Contrasted Plato, emphasizing the need to observe the physical world to gain knowledge.
Origins of Experimental Psychology (19th Century)
The 19th century saw the emergence of distinct schools of thought, establishing psychology as a separate field from philosophy.
Wilhelm Wundt and Introspection
- Wilhelm Wundt is considered the father of experimental psychology (late 19th century, Germany).
- His work began with introspection, an examination of subjective mental experiences.
- Introspection required individuals to inspect and report on the content of their thoughts.
- Wundt focused on introspection and reaction time, introducing quantification into the study of mental processes.
Structuralism: Deconstructing the Mind
Building on introspection, structuralism emerged, proposing that the mind is composed of small, simple parts, much like LEGO bricks. Edward Titchener was a key proponent.
Limitations of Structuralism:
- Highly subjective and personal.
- Prone to error or bias.
- Lacked objective verifiability by other researchers.
Functionalism: The Purpose of Behavior
Functionalism, in contrast to structuralism, focused on the purpose of behavior – why we do what we do. This perspective was heavily inspired by Charles Darwin’s evolutionary ideas.
- William James, considered the first American psychologist, described thoughts as a “stream of consciousness,” emphasizing their fluid and ever-changing nature.
Evolution, Adaptation, and Behavior
A significant influence on functionalism was Charles Darwin and his theory of evolution. Key tenets include:
- Species change over time based on traits that enhance survival and reproduction.
- Random mutations introduce variations.
- Helpful traits are passed on through natural selection.
- Over generations, species gradually adapt to their environments.
Gestalt Psychology (20th Century)
Gestalt theory posits that the whole of our experience is greater than the sum of its individual parts (e.g., Kurt Koffka). This perspective directly opposed structuralism.
- It emphasizes that how we perceive things is heavily dependent on context.
- Consequently, introspection was deemed an ineffective method for understanding perception.
Psychoanalysis (20th Century)
Sigmund Freud proposed that most behavior stems from unconscious mental processes. He described three key components of the mind:
- Id: Represents unconscious desires and primal urges.
- Superego: Embodies moral rules and ideals, largely unconscious.
- Ego: The rational and conscious part, balancing the demands of the id and superego.
Freud believed that dreams and “slips of the tongue” (Freudian slips) reveal underlying unconscious struggles. Psychoanalysis is his therapeutic method designed to bring these hidden thoughts into conscious awareness, helping individuals understand their conflicts.
Critiques of Psychoanalysis:
- Not scientifically testable.
- Lacks predictive power for behavior.
- Primarily explains phenomena after they occur, rather than predicting them.
Behaviorism (20th Century)
John B. Watson founded behaviorism, an approach to psychology that emphasizes how the environment shapes behavior (prioritizing nurture over nature).
- It became the most popular theory in the 20th century and remains influential today.
- Behaviorism aims to explain and predict behavior using simple, observable rules.
Critiques of Behaviorism:
- Overemphasis on observable behavior.
- Tends to disregard internal thoughts, feelings, and mental processes.
Social and Personality Psychology
These fields developed alongside other psychological areas, utilizing experimental methods to study human influence.
- Social Psychology: Examines how others affect our thoughts, feelings, and actions, focusing on what makes people similar.
- Personality Psychology: Investigates traits, emotions, and behaviors that vary across individuals and situations, highlighting what makes people unique.
Evolutionary Psychology
This field explains mental traits as outcomes of natural selection. While the brain undergoes biological changes, aspects of the mind also evolve through culture.
- Understanding the adaptive problems our ancestors faced provides insight into contemporary human behavior.
Case Study: The “Mozart Effect” and Baby Media
The “Mozart Effect” was popularized by products like Baby Einstein. Initially, one study suggested a small, temporary boost in test scores after 10 minutes of listening to Mozart.
Findings and Rebuttals:
- The reported effect lasted only 10–15 minutes.
- Subsequent studies failed to replicate the effect.
- Newer research indicates that television viewing does not aid learning in children under two years of age.
Key Concepts from Influential Psychologists
Jean Piaget: Cognitive Development
- Proposed that cognitive development occurs in fixed stages, which all children progress through in a specific order.
Sigmund Freud: Dreams
- Believed dreams are expressions of the unconscious mind, revealing hidden wishes and desires.
The Scientific Method
The scientific method comprises three key components:
- Theory: A broad explanation for why something occurs.
- Hypothesis: A specific, testable prediction derived from a theory.
- Research: The systematic collection of data and its quantitative analysis.
HOMER: A Framework for Scientific Inquiry
The acronym HOMER outlines the steps of the scientific method:
- Hypothesize: Make a specific, testable prediction.
- Operationalize: Clearly define how variables will be measured.
- Measure: Collect data in a structured manner.
- Evaluate: Analyze results to determine if they support the hypothesis.
- Replicate/Revise/Report: Repeat the study, adjust if necessary, or publish the findings.
Research Methods: Descriptive Studies
Descriptive studies, also known as observational studies, involve watching and recording people or animals to analyze behavior in a structured and unbiased way.
Types of Descriptive Studies:
- Naturalistic Observation: Observing without interfering in the natural environment.
- Participant Observation: Actively taking part in the situation being studied.
Caveats of Descriptive Studies
- Observer Bias: Occurs when an observer’s expectations distort what they record. This is why introspection is unreliable and why experimenters should ideally be blind to the hypothesis.
- Experimenter Expectancy Effect: The observer’s expectations inadvertently cause a change in the behavior of the subjects being watched.
Pros and Cons of Descriptive Studies
Descriptive studies involve observing and categorizing behavior with minimal interference from the observer.
Advantages:
- Useful in early stages of research.
- Conducted in real-world settings, enhancing ecological validity.
Disadvantages:
- Susceptible to observer bias.
- Risk of subjects altering their behavior due to awareness of being watched (Hawthorne effect) or a desire to impress the observer.
Research Methods: Correlational Studies
Correlational studies examine how two variables relate to each other without manipulation or control by the researcher.
Advantages:
- Cost-effective and time-efficient.
- Can be conducted in real-life situations.
Disadvantage:
- Cannot prove causation: They can only demonstrate that variables occur together, not that one causes the other.
Example: A humorous observation notes that both the number of pool drownings and Nicolas Cage movie releases increased, but this does not imply that Cage caused the drownings.
Establishing Causation and Addressing Confounds
To assert that an independent variable (IV) causes a dependent variable (DV), the IV must be the sole difference between experimental groups.
- A confounding variable is anything else that also affects the DV, providing an alternative explanation for the results.
- This includes issues like experimenter expectancy or observer bias.
- To mitigate confounds, both participants and researchers should be unaware of group conditions (a double-blind procedure).
- If confounds are present, even repeated studies cannot definitively confirm true causation between the IV and DV.
Random Sampling vs. Random Assignment
- Random Sampling: The process of selecting who participates in a study (occurs before the experiment).
- Random Assignment: The process of allocating participants to different experimental groups (occurs during the experiment) to ensure the independent variable is the true cause of changes in the dependent variable.
Research Methods: Experimental Studies
Experimental studies involve researchers intentionally manipulating variables to test their relationships.
Advantages:
- Can definitively prove causation (that one variable causes another).
Disadvantages:
- Can be expensive.
- May sometimes feel artificial or lack ecological validity.
- Results may not always generalize to the broader population.
Validity and Reliability in Research
- Validity: Refers to how well a study measures what it intends to measure (e.g., is it measuring a music effect or a stress-relief effect?).
- Reliability: Refers to the consistency and stability of results across different times or studies (e.g., does the Mozart effect yield consistent results over time?).
A study can be reliable but still lack validity if its design is flawed. For instance, consistently hitting the same wrong spot on a target demonstrates reliability but not validity. Scattering shots all over shows neither, while consistently hitting the bullseye demonstrates both validity and reliability.
Types of Validity
- Internal Validity: Ensures that the observed results are genuinely caused by the independent variable, rather than by confounding factors.
- External Validity: Indicates how well the study’s results can be generalized to populations and settings beyond the specific study (e.g., to people other than just UCD psychology students).