Abnormal Psyc Class 2 1/15/2013 10:41:00 AM
Etiological theories of disorder
• Etiological theories explain the origin of abnormal beh.
• Good theories yield hypotheses that can be empirically evaluated
• Resulting hypotheses are either supported or falsified; the theory is either
supported, modified, or rejected
• Theories are more likely to drop out of favor than they are to be rejected
• There are no monocausal theories of anything that are correct
• Reflects the complexity of abnormal human beh.
TOPICS FOR TODAY, JAN 15
1. Research methods in child psychopathology/clinical child psyc.
3. Classification… etc…
1. Research… psychopath..psyc
Research on etiology (today)
Research on treatment (Jan 29 )th
• Good research tests specific hypotheses based on theory
• Hypothesis: prediction about relationship between constructs
- Construct: a psychological abstraction that must be
operationalized for research
- Can’t be proven, only supported (or not) by data
- Can (and should) test many different ways
• Once you’ve operationalized your constructs (and received ethics
approval), you next…..
• Collect data (i.e., scores on the constructs of interest)
• Conduct a statistical test
• Yields probability that results due to chance (p value less than .05 is
Stat significance doesn’t mean findings are important Clinical vs statistical significance.
Research on etiology in psychopathology: Background
• Usually, correlational designs (rather than strictly experimental) are used
- E.g. stressful life events and depression
Recall, experimental means something MUST BE MANIPULATED.
• Measure two variables and estimate their degree of relationship
• Typically calculate a correlation coefficient (r), a number between -1 and 1
• r = 0 (and around zero): variables are unrelated; r =1 means perfect
Correlations often misinterpreted to infer causality
• More parent-child time together is assoc. with higher child GPAs
• What type of correlation is this?
• How is it commonly interpreted?
• What are alternative interpretations?
Research on etiology cont’d
• Two broad, basic design distinctions typically seen in psychopathology
Cross-S vs Longitudinal designs
• Cross-S designs – most common, easy to implement
Cannot infer causality
A cross-sectional study is an observational one. The defining feature of a cross-sectional study is that it can compare different
population groups at a single point in time. Think of it in terms of taking a
snapshot. Findings are drawn from whatever fits into the frame.
• Longitudinal designs – attempt to address causality. If IV precedes DV,
causality is SUPPORTED, but NOT established.
Cohort effects (cohort effect is used in social science to describe
variations in the characteristics of an area of study (such