1. Temporal precedence 2. Existence of a relationship 3. Elimination of Rival Plausible Explanations

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1 Ci Criminology i 860 Experimentation: Deconstructing Donnerstein & Berkowitz Remember John Stuart Mill s 3 Criteria for inferring the existence of a causal relation 1. Temporal precedence 2. Existence of a relationship 3. Elimination of Rival Plausible Explanations 1

2 Mill s criteria are elegantly addressed in the classic experiment Temporal precedence: Because you cause the cause to occur, and exert manipulative control over the setting, you can assess when the change happens. Relationship: You can assess whether, overall, the degree of change is beyond what you d expect on the basis of chance variation alone. Rival Plausible Explanations: These are handled by random assignment and control groups Internal Validity The extent to which differences observed in the study can be unambiguously attributed to the experimental treatment itself, rather than to other factors. (Campbell and Stanley, 1963). That is, how do we know the change was caused by our independent variable rather than some rival plausible explanation? 2

3 Threats to Internal Validity History Maturation Testing Regression Toward the Mean Selection Instrumentation Mortality Donnerstein & Berkowitz 1. Male intro psych volunteer (M) shows up for experiment; meets a female student t(f) who is actually a confederate fd of the experimenter (E). 2. Tape recorded instructions; study of the effects of stress on learning. F is learner; M is teacher who will deliver shocks when mistakes are made. 3. F goes to study. M writes essay about legalizing marijuana. F asked to evaluate M's essay. F provides written comment says essay is silly and delivers 9 electric shocks to M (where 10 is the worst) to show her displeasure. [Anger manipulation.] 3

4 Donnerstein & Berkowitz 4. F goes back to studying. E asks M to help a friend of mine by rating some films. M says yes and goes down the hall to view/rate. [Blind conditions.] 5. M is randomly assigned to one of four films: (1) neutral; (2) explicit sex; (3) sexually violent rape, positive ending; (4) sexually violent rape, negative ending 6. M returns. D&B s interest (DV) is in average shock. 7. Results: No diff between 1 and 2; no diff between 3 and 4; significant difference of [1&2] vs [3&4] Evaluating Donnerstein & Berkowitz Research programme highly influential. Donnerstein, Malamuth, and Check claimed it showed violent pornography contributed to sexual violence against women. In Little Sisters v The Queen, Ml Malamuth argued results were generalizable to gay literature and gay/lesbian relations. 4

5 1. Considering Internal Validity Consider the possible threats. Did D&B adequately control for: History? Maturation? Testing? Regression Toward the Mean? Oh Other threats? Yes, as we discussed last day, because of random assignment and standardized procedures Other Validities External Validity: The extent to which the results of the study are generalizable to other persons, settings, times Ecological Validity: The extent to which the experimental scenario is representative of the milieu to which one wishes to generalize 5

6 2. Considering External Validity Can the results be generalized from male introductory psychology students to males in general? Perhaps a good example of where the uniqueness of the sample works in its favour. Can the results be generalized from inter gender to intra gender relations? Malamuth argues yes; Palys sceptical 3. Considering Ecological Validity The lab research shows it can happen. But does it happen in the real world? Malamuth, in his academic writings, is cautious. As expert witness to the Crown, the caution disappears. Some research by William Fisher addresses the question directly. Fisher makes the following ecological comparisons: 6

7 3. Considering Ecological Validity Lab Context Only means of communication is via delivery of shock Aggression encouraged Aggression trivial No consequences for aggressor No consequences for victim Real world context Other modes of communication are possible Aggression discouraged Aggression severe Consequences for aggressor Consequences for victim Evaluating the D&B Experiment Internal validity is strong External validity probably good for M F/heterosexual Looking for general behavioural principles Using intro psych students may underestimate the effect Nothing happens without anger manipulation Does not work with male male Ecological validity questionable 7

8 Evaluating the Experiment Valuable for its precision and the way it deals with internal validity. External validity up for grabs; ecological validity more questionable. Over reliance on deception as true now as before. Privileged experimenter making distanced decisions about how people think. An offensive politic? Embodies a mechanized controlling relationship that many find questionable. If the experiment represents conditions under which truth holds, do we really want to help create conditions like this? Are there other ways to deal with rival plausible explanations? 8