Chapter Two: Research in Abnormal Psychology

\

• Research in abnormal psychology is especially important: a wrong belief in the field leads to suffering
  • Schizophrenia: severe disorder that causes people to lose contact with reality
  • Lobotomies were believed to cure schizophrenia, but this was false
  • Wasn’t disproven until tens of thousands of people had been lobotomized
  • Caused irreversible brain damage that left patients withdrawn

What Do Clinical Researchers Do?

• Clinical Researchers / Clinical Scientists try to discover universal laws / principles of abnormal psychological functioning using the scientific method
• Clinical Practitioners assess, diagnose, and treat individual clients
  • seek an individualistic understanding of abnormal behavior
• Clinical Researchers use three methods of investigation to form hypotheses
  • Case Study: focused on one individual
  • Correlational and experimental methods
  • Observe many individuals
  • Apply procedures uniformly (allows for replication)
  • Use statistical tests to analyze results

The Case Study

• A detailed description of a person’s life and psychological problems

How Are Case Studies Helpful?

• Can be a source of new ideas about behavior
• Can challenge a theory’s assumptions
• Can show the value of new therapeutic techniques
• Can offer opportunities to study unusual problems

What Are the Limitations of Case Studies?

• Reported by biased observers
• Rely on subjective evidence
• Low internal and external validity scores
• Little basis for generalization

The Correlational Method

• Correlation: the degree to which events / characteristics vary with each other
• Correlational Method: research procedure used to determine correlation between variables
• Subjects / Participants: people chosen for a study
• Sample: collective name for participants in a sample
  • Must be representative of the larger population

Describing a Correlation

• Line of best fit
  • Positive Direction: when variables change the same way. shows positive correlation
  • Negative Direction: when variables change in different ways. shows negative correlation
  • Unrelated variables: there is no consistent relationship between variables and no slope
• Magnitude: How closely do the two variables correspond?
  • The closer the data points are to the line of best fit, the greater the magnitude between the variables
• Correlation Coefficient
  • Positive / negative sign of the coefficient signifies direction
  • The number represents its magnitude - the closer it is to zero, the lower the relationship the variables have

When Can Correlations Be Trusted?

• p < .05: Findings are statistically significant and are thought to reflect the larger population
• The larger the magnitude of the correlation and the bigger the sample ➝ the more likely it is that a correlation will be statistically significant

What Are the Merits of the Correlational Method?

• High external validity
• Lack internal validity - describes the relationship between two variables, but doesn’t explain it
  • Variables can be correlated for any reason
  • Correlation doesn’t equal causation

The Experimental Method

• Experiment: research procedure in which a variable is manipulated and the manipulation’s effect on another variable is observed
  • Independent variable
  • Dependent variable
  • Confounding variable
  • To guard against confounding variables, researchers should include a control group, random assignment, and a masked design
  • ex: bias
• Control Group: A group of research participants who are not exposed to the independent variable under investigation
• Experimental Group: The participants who are exposed to the independent variable
• Statistical Significance: Indicates whether a participant’s improvement in functioning occurred because of treatment
• Clinical Significance: Indicates whether the amount of improvement is meaningful in the person’s life

Random Assignment

• Random Assignment: Any selection procedure that ensures that every participant in the experiment is as likely to be placed in one group as the other

• Reduces the effects of preexisting differences

Masked / Blind Design

• Avoids bias in experiments
• Individuals are kept unaware of their assigned group
• Double-Masked Design: Prevents against both patient bias and experimenter bias
• Triple-Masked Design: Experimenters arrange for judges to assess and analyze the outcomes, and the judges are also kept unaware of group assignments

Alternative Research Designs

• aka Mixed Designs / Quasi-experimental Designs
• Designs that intermix elements of both correlational and experimental studies

Matched Designs

• Researchers match the experimental participants with control participants who are similar in age, sex, socioeconomic status, etc.

• Make use of groups that already exist in the world (ex: effects of abuse on children. splits children into groups of abused and not abused)

• Violates the rule of random assignment

• Matched design minimizes confounding variables caused by not using random assignment

Natural Experiments

• Nature itself manipulates the independent variable while the experimenter observes the effects

• Used for studying the psychological effects of natural disasters and other unpredictable events (floods, plane crashes, fires, etc)

Analogue Experiments

• Experimenters induce lab participants to behave in ways that seem to resemble real-life abnormal behavior

• Investigators can manipulate independent variables freely while avoiding ethical and practical limitations of clinical research

• Often use animals as participants

Single-Subject Experiments

• A single participant is observed both before and after the manipulation of an independent variable

• Rely on baseline data (information gathered before any manipulations) that can be compared to data gathered after the manipulation of an independent variable

Longitudinal Studies

• Researchers observe the same individuals on many occasions over a long period of time

Epidemiological Studies

• Determine the incidence and prevalence of a problem in a particular population

• Incidence: Number of new cases that emerge in a population during a given period of time

• Prevalence: Total number of cases in the population during a given period

  • Includes both existing and new cases

• Help researchers identify groups at risk for particular disorders

• Cannot confirm causation alone

Protecting Human Participants

• Institutional Review Boards: Committees of five or more members who review and monitor every study conducted at a research facility, starting at proposal
• Rules:
  • Participants enlist voluntarily
  • Before enlisting, the participants are given informed consent
  • The participants can end their participation at any time
  • The benefits of the study outweigh its risks
  • Participants are protected from physical and psychological harm
  • Participants have access to info about the study
  • Participants have protected privacy
• IRBs are flawed: Ethical principles can’t always be broken down into simple guidelines

\