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disproven until tens of thousands of people had been lobotomized * Caused irreversible brain damage that left patients withdrawn

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

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

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

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

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

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: 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

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

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

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)

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

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

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

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

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