Introduction to Reasoning Psychology 355: Cognitive Psychology Instructor: John Miyamoto 06/01 /2015: Lecture 10-1 This Powerpoint presentation may contain macros that were used to create the slides. The macros aren’t needed to view the slides. If necessary, you can disable the macros without any change to the presentation.

Outline Deductive & inductive reasoning: The heuristics & biases research program The availability heuristic – What is it? ♦ Examples of probability judgment based on the availability heuristic. The representativeness heuristic – What is it? ♦ Examples of judgments based on the representativeness heuristic. Psych 355, Miyamoto, Spr '15 2 Definition - Deductive Reasoning

Psych 355, Miyamoto, Spr '15 3 Deductive Reasoning Deductive reasoning is reasoning.... FROM:Premises that are assumed to be true TO:Conclusions that are certain to be true if the premises are true. Examples of deductive reasoning: ♦ Math problem solving ♦ Logic problems ♦ Four Card Problem Definition of Inductive Reasoning

Psych 355, Miyamoto, Spr '15 4 Inductive Reasoning Inductive reasoning is reasoning.... FROM:Evidence TO:Strength of belief with respect to one or more conclusions (judged likelihood that a conclusion is true) Examples of inductive reasoning: ♦ How likely is it that it will rain tomorrow in Seattle? ♦ How likely is it that the defendant in a criminal trial is guilty? ♦ What do the results of an experiment imply about a hypothesis that is tested in the experiment? ♦ Economic forecasts: How likely is a recession in Europe during 2015/2016? Why Psychologists Are Interested in Inductive Reasoning

Psych 355, Miyamoto, Spr '15 5 Why Psychologists Are Interested in Inductive Reasoning Most real-world questions involve uncertainties. How do people make decisions when faced with risk and uncertainty? Rational decision model: Expected utility theory ♦ Bayesian decision theory ♦ Central assumption of economic theory & business decision making: Rational decision makers obey the Bayesian decision theory Heuristics & biases research: Cognitive critique of the rational agent model. Modern behavioral economics General issue of how humans acquire knowledge from uncertain information. Risk and Judgments of Likelihood

Risk & Judgments of Likelihood How do people make decisions when faced with risk and uncertainty? ♦ Example: Deciding whether to buy a house. Deciding which house to buy among the available choices. ♦ Example: Deciding what medical treatment is best for a given patient (maybe yourself; maybe for someone else). How do people judge the likelihood of events? ♦ Example: How likely is it that North Korea will sell nuclear technology to terrorists? ♦ Example: How likely is it that you will find a good job if you pursue a career in X, e.g., marketing? How do people judge how much they like or dislike particular possibilities? How do people predict their future preferences? Psych 355, Miyamoto, Spr '15 6 Rational Decision Model & JDM

Rational decision model: Expected utility theory ♦ Bayesian decision theory ♦ Central assumption of economic theory & business decision making: Rational decision makers obey the Bayesian decision theory Judgment & Decision Making (JDM) – a branch of cognitive psychology; generally critical of the rational decision model ♦ Human cognitive processes lead to counterproductive (suboptimal) judgments and decisions Heuristics & biases research: Cognitive critique of the rational agent model. ♦ Heuristics & biases research program is a major part of JDM research. Psych 355, Miyamoto, Spr '15 7 Definition - Heuristic Reasoning Strategies

Psych 355, Miyamoto, Spr '15 8 Heuristic Reasoning Strategies Heuristic reasoning strategies – reasoning strategies that are useful because they are easy and generally effective, even though they can sometimes lead to errors. Main Claims of the Heuristics & Biases Movement

Psych 355, Miyamoto, Spr '15 9 Main Claims of the Heuristics & Biases (H&B) Movement Human cognitive processes do not follow the pattern of a rational model. ♦ (Rational model = expected utility theory & Bayesian decision model) Human decision making uses heuristic strategies that are useful, but they can lead to systematic errors. Heuristic reasoning strategies.... ♦.... are often fast and effective, ♦.... place low demands on cognitive resources. ♦.... but they can lead to errors in particular situations. Behavioral economics – the application of cognitive psychology to the analysis of economic behavior. Heuristic Reasoning Strategies - Definition

Psych 355, Miyamoto, Spr '15 10 Some Heuristics in Inductive Reasoning Availability Representativeness Anchoring & Adjustment Confirmation bias Focusing illusion Framing effects Mental accounting More heuristics that have been proposed than are listed here. Availability Heuristic

Psych 355, Miyamoto, Spr '15 11 Availability Heuristic Availability heuristic – events are judged more probable if similar events are easy to recall or easy to imagine. ♦ In general, frequently encountered events are easier to recall. ♦ The availability heuristic exploits the converse of this relationship: Events that are easy to recall are thought to be frequent in occurrence. ♦ Availability heuristic causes biased probability judgments when other factors that influence availability are not taken into account. Frequency of Experience Other Factors Availability of Memory for an Event Learning Availability of Memory for an Event Judged Frequency of Experience Judgment Same Slide Without Emphasis Rectangles

Psych 355, Miyamoto, Spr '15 12 Availability Heuristic Availability: Lists of Famous & Non-Famous Names Frequency of Experience Other Factors Availability of Memory for an Event Learning Availability of Memory for an Event Judged Frequency of Experience Judgment Availability heuristic – events are judged more probable if similar events are easy to recall or easy to imagine. o In general, frequently encountered events are easier to recall. o The availability heuristic exploits the converse of this relationship: Events that are easy to recall are thought to be frequent in occurrence. o Availability heuristic causes biased probability judgments when other factors that influence availability are not taken into account.

Availability Bias Due to Ease of Encoding Famous/Non-Famous Names x Male/Female Subjects saw a list of names, one at a time, that mixed famous males with non-famous females, or vice versa. There were 18 famous and 19 non-famous names in the list. Psych 355, Miyamoto, Spr '15 13 Condition I: Famous Male Non-Famous Female Bill Clinton Tom Hanks Michael Jordan Mary Brooks Andrea Forbus Leanne Faris Condition II: Famous Female Non-Famous Male William Hale Murray Jencks Lionel Worley Michelle Obama Angelina Jolie Sarah Palin Next: Same Slide with No Barriers & Results

Results: Famous/Non-Famous Names x Male/Female Results: Subjects reported more males if the males were famous; Subjects reported more females if the females were famous. Availability influences perceived frequency. Psych 355, Miyamoto, Spr '15 14 Condition I: Famous Male Non-Famous Female Bill Clinton Tom Hanks Michael Jordan Mary Brooks Andrea Forbus Leanne Faris Condition II: Famous Female Non-Famous Male William Hale Murray Jencks Lionel Worley Michelle Obama Angelina Jolie Sarah Palin Reminder of Link to Memory Model

Psych 355, Miyamoto, Spr '15 15 Availability Heuristic “Other Factors” that influence availability of a memory Famous names are easy to encode and easy to retrieve. Non-famous names are harder to encode and harder to retrieve. Frequency of Experience Other Factors Availability of Memory for an Event Learning Availability of Memory for an Event Judged Frequency of Experience Judgment Studies of Solo Status

Egocentric Bias (Example of Availability Heuristic) Egocentric bias: People overestimate the proportion of the total work that they have contributed to a project. Ross & Sicoly (1979): Subjects were 37 married couples. Working separately, husband and wife rated self and spouse for their work on 20 activities: making breakfast; cleaning dishes; cleaning house; making important decisions;... ; causing arguments between themselves; making the house messy; irritating spouse. primarilyprimarily husbandwife Psych 355, Miyamoto, Spr '15 16 Predicted Response Pattern If No Bias Existed

Rating Procedure in Egocentric Bias Study Husband and wife rated self and spouse for their work on 20 activities primarilyprimarily husbandwife Subjects rated their responsibility on a line as shown above. ♦ Husband's rating measured as distance from the right end; wife's ratings measured as distance from the left end. ♦ If husband and wife have accurate perceptions of responsibility, the sum of their ratings should equal the length of the line. Psych 355, Miyamoto, Spr '15 17 Predicted Response Pattern If No Bias Existed Wife's Mark Husband's Mark Husband's Rating Wife's Rating

Example: Suppose that Husband & Wife's Ratings Are Consistent With Each Other Husband and wife agree as to contribution of each to a task like washing dishes: primarilyprimarily husbandwife If husband and wife were not egocentric, the couple's ratings would sum to Psych 355, Miyamoto, Spr '15 18 ▐+ 25in husband's scoring ▐+ 75in wife's scoring _________________________ +100total of husband & wife Predicted Response Pattern If Egocentric Bias Exists

Example: Suppose that Husband & Wife's Ratings Are Inconsistent With Each Other Husband and wife disagree about their contributions to washing dishes. primarilyprimarily husbandwife If husband and wife are egocentric, the couple's ratings would sum to more than 100. Psych 355, Miyamoto, Spr '15 19 ▐+ 48in husband's scoring ▐+ 75in wife's scoring _________________________ +123total of husband & wife Results for Egocentric Bias Study

The inconsistent pattern is typical: On many activities,.... Ratings consistently summed to number greater than +100 across many activities, showing an excessive attribution of credit or blame to the self. The result holds for both good things (wash the dishes) and bad things (buy unnecessary things). Psych 355, Miyamoto, Spr '15 20 Husband’s Rating + Wife’s Rating > 100 Conclusion re Egocentric Bias – Relation to Availability

Psych 355, Miyamoto, Spr '15 21 Conclusion re Egocentric Bias Egocentric bias is probably due to the greater availability of self- actions than partner actions Other Examples: ♦ Self versus supervisor focus in attributing responsibility for BA thesis work. ♦ Basketball players attributing responsibility for win or loss. ♦ People generally overestimate the frequency of dramatic, newsworthy events relative to the frequency of mundane but serious diseases or accidents. Sampling Bias in Everyday Media

Psych 355, Miyamoto, Spr '15 22 Sampling Bias in Everyday Media Things we all know: ♦ TV ads do not give an accurate picture of the value of products. ♦ Political spin doctors are trying to manipulate our beliefs. ♦ TV news is emphasizes dramatic events; it ignores undramatic events. ♦ The portrayal of men/women, black/whites, rich/poor, gay/straight, on TV is not a representative presentation of these groups. ♦ Our own experiences are not typical of everybody’s experience. ♦ Etc. We all know that these information sources are biased, but can we really correct for these biases when forming beliefs? Doubtful. Return to the Diagram of the Availability Heuristic & List of “Other Factors”

Psych 355, Miyamoto, Spr '15 23 Monday, June 01, 2015 : The Lecture Ended Here

Psych 355, Miyamoto, Spr '15 24 “Other Factors” that Influence the Availability of Events Examples of “Other Factors” Egocentric bias. Dramatic events seem more common than non-dramatic events. Biases in the media create biases in the availability of stereotypes. Recent events seem more common than earlier events. Anything that makes events easier to encode or retrieve can make the events seem more frequent than they are. Summary re the Availability Heuristic

Judging probability in terms of availability is a heuristic. ♦ I.e., it is generally a reasonable way to estimate likelihood, but it can lead to certain systematic errors. Factors that are not related to experienced frequency can make make particular events very available. ♦ E.g., the perceived probability of being killed by a random crazy person will tend to be exaggerated. Psych 355, Miyamoto, Spr '15 25 Introduction to the Representativeness Heuristic