AP Psychology - Intro to Psychology: Research Methods

What is Psychology?

  • The scientific study of behavior and mental processes.
    • Scientific study: Information is collected through systematic procedures, including records of observations and measurements. Knowledge is based on inferences from data and is open to inspection and criticism. Key aspects include curiosity, skepticism, and humility (the idea that "the rat is always right").
    • Behavior: Any activity that can be observed and measured, including:
      • Actual movements.
      • Verbal or written communication.
      • Physiological, visceral, and bodily changes.
    • Mental Processes: Thoughts, memories, emotions, motivations, dreams, perceptions, and beliefs.
      • These are not directly observable, recorded, or measured, posing a challenge for study.
      • Contemporary psychology studies these by observing changes in specific situations and inferring mental processes.

Roots of Psychology

  • Historical influences: Prehistoric times, Egyptians, Greeks, and the Middle Ages.
    1. Wilhelm Wundt (1832-Germany): Introspection/Structuralism
      • Considered the Father of Psychology.
      • Established the first psychology lab for research.
      • Focused on studying consciousness by having subjects report on their own subjective experiences.
      • Aimed to identify the basic building blocks of experience.
      • Edward Titchener, a student of Wundt’s, is also credited with introspection and structuralism.
    2. William James (1875-America): Principles of Psychology/Functionalism
      • Established the first American Psychological Lab at Harvard.
      • Authored a landmark two-volume text.
      • Proposed that humans adapt to their environment.
      • Emphasized the individual.
      • Mary Whiton Calkins: Studied under James but was denied a degree because she was female; she later became the first female president of the APA.
    3. G. Stanley Hall
      • Organized psychology in the USA.
      • A student of James and Wundt.
      • Established the APA (American Psychological Association) in 1892 at Clark University.
      • Founded the first psychology journal, the "American Journal of Psychology."
    4. Dorothea Dix
      • A reformer of mental health treatment in the U.S.
      • Founded the first mental hospital in Pennsylvania.
      • Advocated for reforms and better care for the mentally ill.
    5. Margaret Floy Washington
      • First female to earn a Ph.D. in Psychology from Harvard.
      • Second female president of the APA.
    6. Nellie Bly (Elizabeth Jane Cochran)
      • An undercover reporter who investigated asylums and reported on the horrendous treatment of patients.
      • Her book, Ten Days in a Mad House, prompted reforms and changes.

Major Perspectives in Psychology

  1. Neuroscience/Biological Perspective
    • Combines multiple disciplines, including physiology, brain studies, and neuroanatomy.
    • Focuses on the study of mental processes and their chemical underpinnings.
    • Central idea: "Everything psychological is biological.", meaning every behavior, feeling, and thought is a physical event in the brain.
  2. Psychodynamic/Freudian Perspective
    • Sigmund Freud (1856-1939): Influenced the entire field of psychology.
    • Emphasizes the importance of unconscious forces on human behavior.
    • Introduced psychoanalysis: views humans as irrational and motivated by biological drives.
    • These drives seek an outlet or expression.
    • Considered unscientific but more philosophical.
    • Introduced key concepts such as defense mechanisms.
      • Repression: Innate drives are repressed/buried/pushed out of conscious awareness but still demand satisfaction.
      • Anna O: A patient (not actually Freud’s) who suffered from paralysis of limbs, nausea, and speech disturbances.
        • Joseph Breuer, a colleague, used hypnosis, and she spoke freely of emotional experiences, which alleviated her symptoms.
      • Catharsis: Expression of intense emotions, providing cleansing or reduction of feeling through expression, can improve symptoms.
  3. Behavioral Perspective
    • Emerged because the psychodynamic perspective was considered too unscientific.
    • Focuses on studying ONLY observable, measurable behavior.
      • Classical Conditioning: Pavlov & Watson. Association learning (involving a reflex).
        • Watson coined the term "behaviorism."
        • Stated that only observable behavior is a proper subject for investigation.
      • Law of Effect & Operant Conditioning: Thorndike & Skinner. Association learning (behavior with an outcome/consequences).
  4. Humanism
    • Presents shortcomings of both psychodynamic theory and behaviorism.
    • Emphasizes feelings, experiences, needs, and problems of the whole person.
    • Key figures: Maslow and Rogers.
  5. Cognitive Perspective
    • Focuses on the way we process or transform information.
    • Concerned with mental processes of thinking, knowing, perceiving, attending, and remembering.
    • Circles back to Aristotle and Wundt.
  6. Eclectic Perspective
    • Utilizes all perspectives.

The Scientific Method

  • Emphasizes stringent empirical testing to prove a theory right or wrong.

  • Starts with curiosity and a desire to understand, leading to a theory that explains behavior based on experiences and organizes ideas.

  • Theories do not prove anything and must be tested.

    1. Testable Hypothesis: Asks a specific question in a clear, focused, and testable manner.

      • A testable proposition about behavior or mental processes that is subject to empirical testing.

      • To show cause and effect, it's often framed as an "if, then" statement.

        • Hindsight Bias (I Knew It All Along Phenomenon): The false idea that common sense can predict the outcome or event. Ie. “Absence makes the heart grow fonder” vs “ Out of sight, out of mind”.

        • Overconfidence: The tendency to be more confident than correct.

        • Falsifiability: The possibility that an idea, hypothesis, or theory can be disproven by observation or experiment.

        • Null Hypothesis: A statement that assumes no significant difference or relationship between variables being studied.

          • It is the default assumption unless evidence proves otherwise.
          • If the null hypothesis is true, then any effects are due to chance alone.

    2. Operational Definition: States terms in ways that can be observed and measured to control for bias.

      • Involves stating EXACTLY what is meant and EXACTLY what is being studied, observed, and measured.
        • Example: Defining "happy" could involve a self-evaluation score from 1-10, the number of times someone starts a laugh, or how long someone maintains eye contact.
        • The specific definition might be arguable but clarifies how the term is defined for the purpose of the study.
        • Example: "Better health" could be measured by heart rate, and "Better in school" by the number of correct answers on a quiz.

    3. Reporting Conclusions: If a study is appropriately designed to answer specific questions and data is collected in a careful, unbiased manner, then meaningful conclusions can be drawn.

      • Replication: If designed and executed carefully, another researcher should be able to replicate the findings.
      • Peer Review: Scientific experts evaluate a research article’s theory, originality, and accuracy.

Experimental Methods

  • Designed to show causation.
  • Must have random assignment.
  • Scientists treat an object/subject in a certain way and then observe the effects of that treatment. Experiments are a form of stringent empirical testing, providing evidence to prove a theory right or wrong and starting with curiosity and a desire to understand.
    • Examples
      • Hinsz and Tomhave study on smiling: (From the idea that if you laugh, the world laughs with you; if you cry, you cry alone).
        • ⅕ smiled with a neutral expression coming towards them.
        • Frowns did not get smiles or frowns.
      • Liebert & Baron study on kids observing violence on TV: Showed kids violent show (The Untouchables) or athletic competition. Aggression was defined in 10-second intervals and measured while playing with an aggressive toy or assaulting Bobo doll).
        • Those viewing violence behaved more aggressively.
    • Independent Variable: Varied and manipulated by the experimenter.
      • What is hypothesized to CAUSE change. (The experimenter controls this aspect).
    • Dependent Variable: Theoretically affected by the independent variable.
      • The possible behavior change that results from the experiment.
    • Control Group
      • Subjects not exposed to the independent variable.
      • In drug/treatment trials, this group receives a placebo (inert substance or conditions, i.e., sugar pill)
    • Experimental Group
      • Subjects that are exposed to the independent variable being studied.
    • Random Assignment: Assigned to groups (experimental & control) BY CHANCE, eliminating bias and results due to outliers.
      • Can be achieved using a coin flip OR computer-generated list of random numbers.
      • Population: the group of people that have the opportunity to be selected for the study, samples drawn from (except for national studies, this does not refer to a country’s whole population)
      • Random Sample: Selected from the population that fairly represents a population because each chance
      • Random Assignment: Required for an EXPERIMENT to assign participants to experimental and control groups by chance, thus minimizing the preexisting differences between the different groups
      • Convenience sample: A non-probability sampling method that involves selecting a sample of people who are easy for the researcher to access ie. people on the street, students in a class
      • Sampling bias: A flawed sampling that produces an unrepresentative sample
    • Confounding variables: Extraneous variables that could affect the dependent variable.
      • Example: IQ scores and home environment. Random assignment helps and allows for better replication.
      • Nut/bolt study: Choice of partner, choice to go first or second, position of nuts/bolts.
    • Single Blind: Subjects are uninformed about the purpose of the study
    • Double Blind: Subjects and researchers working with and analyzing the data are uninformed about the purpose of the study.
      • Mandatory in drug/treatment trials.

Non-experimental Methods

  1. Naturalistic Observation

    • Subjects are observed in their natural environments.
    • The observer does not attempt to interfere with the natural behavior of the subject.
    • Subjects are usually unaware of being observed/studied.
    • Ethology: Study of animals in natural habitat.
    • Tells what behavior is, but not why it occurs.

  2. Case Study

    • Extensive study of all or part of the LIFE HISTORY of an individual.
    • Essential in understanding and helping psychological disorders.
    • Illustrates ideas and relationships in teachings.
    • Research tool to suggest theories or hypotheses; generates a POSSIBLE WHY behavior occurs, and generates a possible hypothesis.

  3. Surveys

    • Used for larger groups.
    • Measures attitudes and behavior patterns using questionnaires (in-person, phone, email, etc.).
      • Identify "population" (entire group that subjects will be pulled from) then statistically randomly selected from the population
    • Results often counter common beliefs.
      • Example: Kinsey Report (1940s) on premarital sex. It was thought that men were much more likely to engage in premarital sex, but the stats showed 68% of males and 60% of females.
    • Problems:
      • Honesty of responses.
      • Asking the same question in 2-3 different ways to ensure honest responses.
        • Framing: How a question is posed can affect how someone responds to it.
        • Social desirability bias: People answer a survey in the way they think will please the researcher.
        • Self-report bias: People don’t accurately report or remember their behaviors.

  4. Correlational Studies

    • Seeing if variables are related or go together (correlated).

    • Sir Francis Galton

    • Changes in one variable (event) are associated with changes in another variable (event).

    • Correlation DOES NOT equal causation!!!!

      • 3rd Variable Problem: Another event connects the 2 variables.
        • Example: Observing that better health and exercise are correlated. Those who exercise may be more likely to eat better, and that is what causes the better health, not necessarily the exercise itself.
        • Ice cream sales & rape
        • Ice cream sales & drownings
      • Positive Correlation: High with high, low with low. Both events go in the same direction.
      • Negative Correlation: High with low. Both events go in opposite directions.
      • Scatter Plot: A graph showing visual representation of the 2 variables/events.
      • Correlational Coefficient: Computed numbers that express the degree and direction of relationships that can range from −1.00-1.00 to +1.00+1.00.
        • 00 = NO RELATIONSHIP.
        • Closer to 1 whole = the stronger the relationship
        • (+ & - DO NOT effect the strength of the relationship).
        • .0.0 to −.3-.3, 00 to +.3+.3 = weak relationship
        • .3.3 to .7.7 (+ or -) = moderate relationship
        • .7.7 to 11 (+ or -) = strong relationship
      • Illusory Correlation: perceiving a relationship where none exists or perceiving a stronger-than-actual relationship

  5. Qualitative Measures

    • Relies on in-depth, narrative data that are not translated into numbers.
    • Example: Structured interviews.

  6. Quantitative Measures

    • Relies on quantifiable, numerical data.
    • Example: Likert scales.

Descriptive Statistics

  • Techniques borrowed from mathematics used to describe data, determine probability, determine if results are “due to chance” or “statistically significant” (= NOT DUE TO CHANCE), and guide inferences made from data.
    1. Distribution: How scores are spread out across the range of possible values, usually low to high in order.
    2. Bell Curve/Normal Curve/Normal Distribution: Symmetrical, unimodal, defined by a specific formula. Key percentages: 68, 95, 99.
      • Mean, median, and mode are the same.
      • 1 line of symmetry (measures of central tendency).
    3. Measures of Central Tendency
      • Mean: Average; sum of scores in distribution, divided by number of scores. Too ambiguous (i.e., "average adult would have 1 ovary and 1 testicle").
      • Median: Value in the middle of the distribution, 50% above and 50% below this point (half the scores). Often a better measure if there are outliers.
      • Mode: Most frequently occurring score; least used.
    4. Outliers: Unusual or extreme score; reason to use median vs. mean.
    5. Skewed Distribution: Occurs with outliers.
      • One “tail” or extreme end (the extreme score pulls the mean) is longer, to the right (+ positive skew) or left (- negative skew).
      • Mean shows direction of skew, Median is always in the middle, Mode on the opposite side (the hump).
      • Outlier pulls the Mean to the direction of the skew (tail).
    6. Bimodal Distribution: When two clearly separate groups are visible in a histogram. Characterized by 2 modes or 2 distinct clusters of data
    7. Measures of Variability
      • Range: Value/distance from highest to lowest score.
      • Standard Deviation (SD or S): How scores “deviate” or are different from the mean.
        • 68% are 1 SD from the mean (34% above & 34% below).
        • 95% are 2 SD from the mean (47.5% above & 47.5% below).
          • Also, 95-68=27.5, split in half (half above and half below).
          • SO, 13.5% are from 1 to 2 SD above and 13.5% are 1 to 2 SD below
        • 99% are 3 SD from the mean (49.5% above & 49.5% below).
          • Also, 99-95=5%, split in half (half above & half below)
          • SO, 2.5% are from 2 to 3 SD above and 2.5% are 2 to 3 SD below
        • MOST used measure of variability.
          • (for informational purpose ONLY…you do not need to do this)
            1. Compute the Mean.
            2. Subtract the Mean from each score to find each scores difference from the mean.
            3. Square each difference/deviation (gets rid of negatives).
            4. Add the squares.
            5. Divide result by the number of scores.
            6. Find the square root of result…this is the SD
    8. Percentile rank: From 0 (lowest, all the way to the left) to 99th (highest, all the way to the right).

Ethics in Psychology

  1. Preamble of the APA: ”Respect the dignity and worth of the individual, strive to preserve and protect human rights, increase knowledge, protect the welfare of those seeking services."
  2. Rights Research participants, consider benefits to society and dignity and welfare of subjects, advantages, alternatives, purposes, deception.
    • Maintained by the IRB (Local Institutional Review Board) Committee that reviews research proposals involving human subjects to ensure they are ethical and protect the participants' rights and welfare. Federally mandated and locally administered, legally required
  3. Care of animals Safeguard health, comfort, and humane treatment, minimize chances of pain, illness and discomfort, must be necessary for progress, advantages, IRB and IACUC (Institutional Animal care and Use Committee).
  4. Informed consent & assent (not able to give own legal consent) Need to be told enough to make choice to participate
  5. Confidentiality Information provided by others seeking counseling, studied in work, students, and research subjects.
  6. Use of deception Committee of Standards in Research, CSR, monitors ethical issues Necessary but brings up ethical issues Often done with the use of confederates-individual(s) who seem to be participants but in reality are part of the research team
  7. Debriefing Make subjects aware of what the study was about, the true nature of the study, and discovered, Mandatory especially when deception is used