Final Exam Study Guide PHI 2100 01 Concepts you should be able to explain and recognize examples of Look over the concepts from last test such as Base Rates and Fallacies Test is not cumulative Representativeness Heuristic We tend to make judgments by using stereotypes our idea of the representative X Stereotypes have a negative connotation but we can t get along in the world without using stereotypes Clustering Illusion we expect chance sequences to be less streaky than they really are therefore we re surprised by how streaky random sequences are Note This is why gamblers believe it in hot cold streaks when it comes to gambling We are SURPRISED by how streaky chance sequences are Base Rate Paradox Conjunction Fallacy a more specific demanding description that fits our stereotype will be seen as more probable than a less specific demanding description that does not fit our stereotype Easy Explanation deals with Hindsight Bias we are naturally story tellers and so we are very good convincing but unsupported explanations for things after they occur It gives you a FALSE sense of understanding Whenever you offer an explanation for some piece of behavior you should ask yourself two questions o 1 Consider the opposite if something else had occurred could I have explained that too If Yes probably an easy explanation that offers a false sense of understanding o 2 Prediction Could I have predicted this BEFORE it happened If NO probably an easy explanation that offers a false sense of understanding o Examples John s mom is a bartender John worked at the bar during high school If after college he goes to work at the bar people can explain it as follows he missed the bar If he doesn t people can explain it as follows it s the only job he s ever had he hates it Regression Fallacy ignore regression to the mean easy explanation we often explain regression effects with unnecessary causal factors whenever occurrences of X vary around a mean if X1 is extreme X2 is likely to be closer to the mean Availability Heuristic convenient memory we tend to think events are more probable to the extent they are more available to memory Often the availability heuristic works well Often events are available to memory because they really do happen a lot BUT sometimes our memory is selective and we remember things that are VIVID or DRAMATIC or ANNOYING of FIT W OUR THEORIES This tends to happen when events are two sided Two sided events both potential outcomes would be equally noticed or remembered one sided events only one outcome would be noticed remain in memory Some events that are inherently one sided o Pattern asymmetries o Hedonic asymmetries only one outcome arouses emotion or requires an act you tend to remember events that stand out or seem on your part Ex all of the buses are heading the wrong direction to be the result of a pattern Ex Always saying that you woke up in the middle of the night at 1 23 very often tell when someone has had plastic surgery when you do detect it you notice and remember but if you can t tell that someone has had plastic surgery then you don t have any information about it usually one sided almost by definition Ex I can always o Definitional asymmetries Biased Interpretation we often interpret data that contradicts our pet beliefs as BAD LUCK or as ALMOST CONFIRMING our views Ex Person with hot hands misses we would say he just missed it Fortune Cookie Problem no specific prediction the prediction is so vague and general that it could be applied to almost everyone NO experience would disconfirm your pet belief NO time frame and vague Real fortune cookies negotiations move along smoothly the outcome is favorable and you will see through the illusion to the plain truth Ask yourself is there any experience I could have that would convince me my pet belief was false If not you may be the victim of the fortune cookie problem Ex good things come to those who wait The time frame is ambiguous eventually good things happen to most people Optional Stopping When dealing with Pet belief Negative evidence critical scrutiny explain away STOP No more ciritcal scrutiny Positive evidence STOP No more critical scrutiny Are you equally critical of reasons that tend to support your view of something that is important to you i e politics abortion etc as you are of reasons that tend to undermine your view PROBABLY NOT which Then you are probably guilty of optional stopping Note you re not IGNORING negative evidence you are rather treating negative and positive evidence DIFFERENTLY so it would be unfair to criticize you for being close minded on the other hand it might be easier to correct our mistakes if we were just ignoring negative evidence Correction would just involve attending to all the relevant evidence When given ambiguous inconsistent data people ended up being MORE CONFIDENT MORE EXTREME in their opinions Ex My belief that video games don t incline people to violence Any evidence that it does I critically scrutinize Any evidence that fits my belief I accept Sharpening Leveling Deals with second hand testimony Secondhand accounts become simpler cleaner stories Familiar Examples Testimony is sharpened Testimony is leveled context details qualifications are de emphasized or ignored main point is emphasized o Experience w newspaper stories of events you ve attended o Individuals who you ve heard stories about Often disappointed to meet them Example One night my buddy drove his truck into the side of our house I tried to explain to my mom what happened over the phone When she finally saw the damage she was relieved When we meet people that we have heard about from a friend in either a positive or negative manner we are often disappointed because they seem less extreme than we were led to believe o One reason when we tell stories about a person the story is organized around the person and his actions rather than the context of the situation So the person and his actions are sharpened the context and mitigating circumstances tend to be leveled Expected Value The expected value tells you what your average mean value is per decision given in terms of money So the basic idea is that if you only care about money the thing to do is to take the option that maximizes expected value Maximizing the expected value is not always the rational decision Be able to do the calculation EV Option Pr Outcome a x Value Outcome a Pr Outcome b x Value Outcome b So essentially it is for every option you multiply