Lecture 6 Current Lecture Chapter 4: Research Methods in the Study PsychopathologyI. Science and Scientific MethodsII. Approaches to Research on PsychopathologyIII. Integrating the Findings of Multiple StudiesHow do we know things? (Epistemology) Why are people poor? Why do some people commit crimes? What causes depression? What explains doing good or altruism?Truths that turned out to be myth “Bleeding” a person can be used to cure disease Racial integration of the armed forces will lead to the destruction of morale Women are incapable of voting intelligently Opposites attract Homosexuality is a mental disorder Autism is caused by poor parenting (refrigerator parents)Counterfeits for knowledge Opinion is not evidenceIU is a better school than PurdueUS is best country Argumentativeness is not evidenceName calling (person is socialist) and insults are not evidenceRepetition isn’t evidence (is too, is not, is too!) Common belief does not mean accurate (sensible) beliefpeople who discuss suicide don’tpeople tend to be “crazier” around the time of the full moon (lunacy)How do we know things? Authority (ancients or Holy Book says so)religion, Greek philosophy Ideology (our fixed beliefs define truth, data is relatively unimportant)I know this to be true, this is the way it is Psych 380 1st EditionRocks simply cannot fall from the sky, so if you saw one, you are wrong (meteorites)The earth is roughly 7000 years old (“science” content of religious book is superior to geology textbook) Conceptual (makes sense) Empirical (data, test it)Descriptive methods Naturalistic observation – not in lab (Black Santa) Case study – single cases (common in autism and behavioral therapy) Survey – most common methodScience and Scientific Methods Science = “to know”• The systematic pursuit of knowledge through observation• Scientists gather data to test theories Theory• Set of propositions developed to explain what is observedA good theory is falsifiable- Allows for disconfirmation Hypotheses• Specific predictions about what will occur if a theory is correctPopper’s Falisficationism A theory can never be said to be true• Of a theory it can only be said that it is the best available in the sense that is better than anything that has come before – at least for the time being.  As a consequence• there is no certainty in science• scientific knowledge is always tentative. Case Study Detailed biographical description of an individual• Family history • Medical status• Educational and work background• Information about peer and romantic relationships• Personality and adjustment issues• Current difficulties and prior experiences in therapyCorrelational Method Do variable X and variable Y vary together? • Are they related in a systematic way?Do people who experience more stress have more headaches?  Variables measured but not manipulated Cannot determine cause or effectCorrelation Degree of relation between two variables Two componentsStrength or Magnitude (ignore sign)ranges from 0 (no relationship) to 1 (or -1) (perfect relationship)Direction or Sign (+ or -)Direction of the Correlation Coefficient• Positive correlation: Indicates that the values on the two variables being analyzed move in the same direction. That is, as scores on one variable go up, scores on the other variable go up as well (on average) & vice versa• Negative correlation: Indicates that the values on the two variables being analyzedmove in opposite directions. That is, as scores on one variable go up, scores on the other variable go down, and vice-versa (on average)Longitudinal vs. Cross-sectional Designs Longitudinal• Studies participants over time• Examines whether causes are present before disorder develops • High-Risk MethodInclude only those who are at greatest likelihood of developing a disorderReduces the cost of longitudinal research Cross-sectional• Causes and effects measured at the same time Confounds• Third variable may produce changes in two correlated variablesEpidemiological Research Epidemiology• Study of the distribution of disorders in a population and possible correlates Three features of a disorder• Prevalence• Incidence• Risk FactorsCorrelational Research: Behavioral Genetics Methods to determine genetic predisposition (concordance) to psychopathology• Family Method• Twin Method• Adoptees