Chapter 4 Research Methods Outline Examining abnormal behavior

Chapter 4 Research Methods

Outline Examining abnormal behavior Types of research methods Genetics and behavior across time and cultures Research ethics

Focus Questions o What are the basic components and methods of psychopathology research? o How do researchers study the role of genetics? How do researchers study behavior across time and culture? o Why are ethical principles important in research?

Examining Abnormal Behavior Important questions § What problems cause distress or impair function? § Why do people behave in unusual ways? § How can we help them develop more adaptive behaviors?

Basic Components of Research Starts with a hypothesis or “educated guess” § Not all hypotheses are testable § Hypotheses in science are formulated so that they are testable

Basic Components of Research design § A method to test hypotheses § Independent variable The variable that causes or influences behavior § Dependent variable The behavior influenced by the independent variable

Considerations in Research Design Internal validity vs. external validity § Internal validity: Extent to which results of a study are due to the independent variable § External validity: Extent to which results of a study are generalizable to the population it’s studying Ways to increase internal validity by minimizing confounds § Use of control groups § Use of random assignment procedures § Use of analog models

Statistical versus Clinical Significance Statistical methods – branch of mathematics § Helps to protect against biases in evaluating data Statistical vs. clinical significance § Statistical significance – are results due to chance? § Clinical significance – are results clinically meaningful? § Statistical significance does not imply clinical meaningfulness Balancing statistical versus clinical significance § Evaluate effect size § Evaluate social validity

The “Average” Client? Patient uniformity myth § Researchers sometimes mistakenly see all participants as one homogenous group Generalizability § The extent to which results are applicable to the larger population being studied

Studying Individual Cases Case study method § Extensive observation and detailed description of a single client § Foundation of early historic developments in psychopathology Limitations § Lacks scientific rigor and suitable controls § Internal validity is typically weak § Often entails numerous confounds

Research by Correlation Assess the degree to which levels of certain variables are linked to levels of other variables § Example: Higher levels of education are linked to higher levels of income The nature of correlation § Statistical relation between two or more variables § No independent variable is manipulated § Range from – 1. 0 to +1. 0 § Negative vs. positive correlation

Research by Correlation Necessary in situations where you can’t manipulate variables Limitations § Does not imply causation § Problem of directionality

Epidemiological Research An example of the correlational method Surveys large groups of people to get a picture of an entire population Examines incidence, prevalence, and course of disorders § Examples – AIDS, trauma following disaster

Example of Correlational Relationships

Research by Experiment Nature of experimental research § Manipulate independent variable § Observe effects on dependent variable § Attempt to determine causal relationships § Premium on internal validity

Group Experimental Designs Involves manipulating a variable (i. e. , introducing or withdrawing something in a controlled way) Clinical trial: Experiment designed to evaluate the effectiveness of a treatment Example: Administering a drug

Control Groups in Clinical Trials Control group: Provides a comparison point Often matched to demographics of experimental group Placebo: Some participants are given an inactive treatment (e. g. , sugar pill), but participants don’t know which treatment they are getting Double-blind: Participants and assessors are unaware of what kind of treatment participants are getting Placebo effect: Something changes simply because the participant expects the change to occur (e. g. , expecting to feel better when taking an inactive pill)

Single-Case Experimental Designs Nature of single subject design § Rigorous study of single cases § Manipulate timing and nature of experimental conditions § Frequent repeated measurement of outcomes is critical Permits conclusions about changes over time relative to the introduction and withdrawal of certain variables

Single-Case Experimental Designs Types of single-subject design § Withdrawal designs First establish a baseline, then introduce treatment Then, stop treatment to see if behavior/symptoms return to the way they were before treatment May present ethical concerns if an efficacious treatment is removed

Single-Case Experimental Designs Types of single-subject design § Multiple baseline designs Start treatment at different times in different conditions (e. g. , in home vs. school settings) – see if changes occur in conjunction with introduction of treatment Improves internal validity

Studying Genetics Behavioral genetics § Interactions of genes, experience, and behavior § Phenotype vs. genotype Genotype: Genetic makeup Phenotype: Observable characteristics (e. g. , eye color, degree of shyness) § Endophenotype: Genetic mechanism that contributes to problems causing certain symptoms Example: Group of genes responsible for impairing working memory in schizophrenia

Studying Genetics Family studies § Proband: The person who has the trait of interest (e. g. someone who has schizophrenia) § If there is a genetic influence, expect to see the trait more in first-degree relatives compared to second-degree § Familial aggregation: Tendency of a disorder to run in families § Issue of shared environment: Families usually live together, so similarities may be due to environmental factors as well as genetics

Studying Genetics Adoption studies § One way to separate the effects of the environment § Sibling pairs separated after birth: Do they show similarities even if they were raised in different environments? § Are adopted children more similar to their birth parents (genetics) or adoptive parents (environment)?

Studying Genetics Twin studies § Compare identical/monozygotic twins against fratergnal/dizygotic twins If a trait is genetic, expect to see greater concordance in identical twins (similar environment and same genetics) compared to fraternal twins (similar environment, different genetics) § Can be combined with adoption studies: If identical twins are both adopted separately and raised apart, shared outcomes are more attributable to genetics

Studying Genetics: Locating Specific Genes Genetic linkage studies and association studies § Examine known genetic markers (certain gene whose location is known) § Compare these genetic markers against the trait being studied

Studying Genetics: Locating Specific Genes Genetic linkage studies and association studies § If the genetic marker tends to co-occur with the trait, conclude that the trait is probably caused in part by genes that are in close proximity to the genetic marker (e. g. on the same chromosome) § Genetic linkage studies occur in groups of people who all have the trait of interest § Association studies occur in people with and without the trait of interest

Studying Behavior Over Time Prevention research § Health promotion: Increasing healthy behavior in entire population (even people not at risk for developing disorders) § Universal prevention: Target specific risk factors but not specific people § Selective prevention: Targets groups of people at risk § Indicated prevention: Targets specific individuals who are showing early signs of a disorder

Studying Behavior Over Time-based research strategies § Cross-sectional designs: Take a cross section of the population at different age groups Compare cohorts (age groups) on traits of interest § Longitudinal designs Study one group of people over time Have to take into account specific experiences of the generation being studied (crossgenerational effect)

Studying Behavior Over Time

Studying Behavior Across Cultures Value of cross-cultural research § Overcoming ethnocentric views § Increases understanding of Etiologies Symptom presentations Treatments

Studying Behavior Across Cultures Difficulties in cross-cultural research § Definitions of abnormal behavior § Variance in presentation § Availability of valid assessment instruments may be limited

Programs of Research Components of a research program § Set of interrelated research questions § Draw on several methodologies in finding answers § Conducted in stages, often involving replication Allows for more nuanced, complete picture of a phenomenon Replication is critical § Protects against fluke results

Research Ethics Sometimes, needs of science (e. g. , designing a good experiment) are at odds with needs of research participants (e. g. , need for treatment) § Research ethics determine the degree to which each should be prioritized Ethics determined by institutional review boards (IRBs) & the APA ethics code § Oversee the rights of human subjects participating in research § Make sure research and data are handled responsibly

Research Ethics Ethical principals § Informed consent Became important after WWII after Nazis had forced people to participate in research § Competence – ability to provide consent § Voluntarism – lack of coercion § Full information – necessary information to make an informed decision § Comprehension – understanding about benefits and risks of participation

Summary of Research Methods Nature of research § Establishing and testing hypotheses Research design § Varies depending on the questions posed § Each has unique benefits and drawbacks

Summary of Research Methods Abnormal psychology is founded in the scientific method § Understand the nature of abnormality and human suffering § Understand the causes of psychological disorders § Understand the course of psychological disorders § Understand how to prevent and treat psychological disorders

Summary of Research Methods Replication is the cornerstone of science and programmatic research Research must occur in the context of ethical considerations and values