Class Notes (835,243)
Canada (509,044)
Psychology (6,249)
Lecture 10

Psychology 2032A/B Lecture 10: Lecture-10

6 Pages
Unlock Document

Psychology 2032A/B
John Campbell

Lecture 10: Risk Assessment Risk Assessment: - Risk is vied as a range o Probabilities change across time o Interaction among offender characteristics and situation - Risk assessment has two components o Prediction o Management - In Criminal Settings: o Risk assessments conducted at major decision points:  Pretrial  Sentencing  Release o Public safety outweighs solicitor-client privilege Types of Prediction Outcomes: **exam - Four types of prediction outcomes: 1. True Positive (person will reoffend and you are right) 2. False Positive (person will reoffend and you are wrong) 3. True Negative (person will not reoffend and you are right) 4. False Negative (person will not reoffend and you are wrong) - Two types of errors are dependent on each other (false positive and false negative) - Each outcome has different consequences for offender or society - Decisions vs Outcomes OUTCOME DECISION Reoffends Does NOT reoffend Predicted to reoffend True Positive False positive (correct) (incorrect) Predicted to NOT reoffend False negative True negative (incorrect) (correct) History of Risk Assessment: - 1960s: Civil rights cases involving accuracy of mental health professionals in predicting risk o Baxstrom v. Herald (1966)  Was being detained longer than his sentence and ordered to release him; as a result  More than 300 mentally offenders were released; 98 were too dangerous to be released and were tracked; only 20 were arrested over a 4-year period; only 7 committed a violent offence o Dixon v. Attorney General of the Commonwealth of Pennsylvania (1971)  Out of 400 patients released, only 60 committed a violent act over a 3- year period - Baxstrom and Dixon studies: o Had a base rate for violence that were low o High false positive rate - Not a great start - Ennis and Litwack 91974) characterized clinical expertise in violence risk assessment as similar to “flipping coins in the courtroom” - Other researchers went further, concluding that: “no expertise to predict dangerous behaviour exists and the attempt to apply this supposed knowledge to predict who will be dangerous results in a complete failure” (matched the attitudes of psychologists at this time) - Failure to take into account base rates affects our ability to conduct risk assessments (Steve and Linda activities); conjunction fallacy= B can’t be more likely than A o Steve (shy, withdrawn, little interest in people, meek, tidy, structured, attention for detail) o Linda (single, outspoken, bright, intelligent, concerned with social issues) Base Rates - Represents the % of people within a given pop who commit a criminal/violent act o Prediction difficult when base rates are too low or too high o False positives tend to occur with low base rates - Easier to predict frequent vs. infrequent events Judgement Errors and Biases - Heuristics o General strategies, or rules of thumb, that can be applied to various problems o No guarantee of correct solution as it is not an algorithm o Quicker and more efficient than algorithms o Can be developed for any problem - Illusory correlation - Ignore base rates - Reliant on salient cues - Confirmation bias - Overconfidence Two Major Concepts of Kahneman and Tversky - Availability heuristic o The ease with which an item can be brought to mind o Influences our judgement o Because of the media, we assume certain events to be more prevalent than others (ie. dying of a shark attack vs. dying of a falling airplane part) o We confuse the frequency with which we can actually remember something with how frequently it actually occurs o Ability to make judgements on the information available (ex. most people report rd that the letter R occurs more often in the first positon than the 3 position when the opposite is true) - Representative Heuristic o A strategy used to make predictions based on experience o Allows us to extrapolate info we have experienced to make predictions about the current situation (ex. flipping a coin 8 times, we are more likely to pick that a random order of heads and tails will happen vs. HHHHTTTT order) Illusory Correlation - An illusory correlation exists when a decision is influenced by the perception of a correlation existing between two entities that may not actually be correlated - Quinsey and Maguire o Found that in a sample of experienced forensic clinicians, judgements of dangerousness were based largely on the seriousness of the individuals offence and the frequency of assaultive behavior displayed by the individual while in the institution - Measured over an 11 year period and found the actual risk factors that were successful in predicting dangerousness to be: seriousness of offence, history of crime, and the number of previous correctional confinements - Thus, the clinicians’ consideration of seriousness of offence and frequency of assaultive behavior acting as significant cues associated with dangerousness was only half supported, with the latter cue having no relationship to offender behavior following release Context Effects
More Less

Related notes for Psychology 2032A/B

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.