J/DM 1998 schedule
November 21 - 23
Wyndham Anatole Hotel
Dallas, Texas
Abstracts of posters are available here.
Saturday, Nov 21
J/DM board dinner & board meeting
Graduate Student Social Event (9pm in the hotel sports bar)
- 10:15-11:55
- Psychonomic Society: J/DM I (Grand Ballroom B)
- 10:15-10:25
- Preferences for Future Generations
Gretchen B. Chapman (Rutgers U.)
Three scenarios presented life-
saving programs that differed in the generation and time (year) in
which lives were saved and the age of the recipients. Eighty-three
undergraduates indicated the number of lives saved that would
make the program just as attractive as one that saved 100 lives
now. Almost half the subjects showed zero discounting, valuing
present and future lives equally. The remaining subjects showed
low discount rates (3%-5% annually) and marked consistency
across questions.
- 10:30-10:40
- Failure to Demonstrate the Sunk Cost Effect in a Field
Experiment
Carla R. Scanlan & Hal R. Arkes (Ohio U.)
Students participating in a
term-long dormitory meal plan were randomly selected to receive
either a $200 reduction in the cost of their meal plan or certificates
worth $200 at a local mall. We obtained results contrary to the
sunk cost effect: Compared with those given gift certificates, those
given a price reduction in their meal plan tended to eat a higher
proportion of their meals in the dormitory.
- 10:45-11:00
- Modeling Individual Differences in Risk Attitude.
Lola L. Lopes & Gregg C. Oden (U. of Iowa)
SP/A theory is
used to model individual differences in risk attitude. The
parameters of the model describe two criteria that contribute
independently to risky choice. The SP (security-potential) criterion
captures differences in the relative attention paid to best-case and
worst-case gamble outcomes. The A (aspiration) criterion captures
differences in the impact of outcome goals on choice. Fitted parameter
values reveal systematic processing differences between subjects
selected for high and low security mindedness.
- 11:05-11:25
- The Susceptibility of Young and Old Adults to Positive and
Negative Outcomes of Recent Decisions.
Vered Rafely & Itiel E. Dror (Southampton U.) & Jerome R. Busemeyer (Indiana U.)
Young and old participants performed a decision-making task in which the
outcomes of recent decisions were manipulated. The young
participants turned more conservative in response to negative
outcomes, but were not affected by positive outcomes. In contrast,
the older participants did not change their decisions in response to
either positive or negative outcomes. The data are interpreted in
terms of sequential sampling models and deterioration in accessing
recent memory with aging.
- 11:30-11:50
- Oppositional Deliberation: Toward Explaining Overconfidence
and Its Cross-Cultural Variations
J. Frank Yates (U. of Michigan), Ju-Whei Lee (Chung Yuan U.), Hiromi Shinotsuka (Hokkaido U.), & Winston R. Siech (U. of Michigan)
People are often overconfident in
their general knowledge, and cultures differ reliably in this
tendency. In the present research, subjects "thought aloud" as they
responded to general knowledge questions. Two key results
emerged: (1) Overconfidence occurred strongly only when
respondents approached their task via the generation of arguments,
which typically neglected arguments inconsistent with the answers
respondents actually chose. And (2) respondents in different
cultures differed substantially in their inclination to generate such
"choice-opposing" arguments.
- 1:30-3:15
- Psychonomic Society: J/DM II (Grand Ballroom B)
- 1:30-1:45
- Explaining Attribute Framing Effects: The Half-Full/Half-
Empty Phenmenon.
Irwin P. Levin & Gary J. Gaeth (U. of Iowa),
Sandra L. Schneider, (U. of S. Florida)
& Victoria L. Phillips & Kirsten I.
Redalen (U. of Iowa)
The half-full/half-empty cup, the
procedure that has a 50% success rate/50% failure rate, and the
beef that is 85% lean/15% fat are all examples of attribute framing.
We provide support for an associative model of attribute framing
effects by showing that subjects are more apt to endorse items such
as "hopeful" and "optimistic" in response to scenarios that include
positively framed attributes than to scenarios that include
negatively framed attributes.
- 1:50-2:10
- Framing Effects in Medical Treatment Choices: Anchoring Not
Risk Preference.
Sandra L. Schneider & Andrea L.
Washburne (U. of S. Florida)
Previous framing
studies have demonstrated conflicting results regarding preferences
for medical treatment options involving tradeoffs between risks.
Combining treatment features from McNeil et al. (1982) and
O'Connor et al. (1985), we manipulated short-term survival
outlook, quality of life, and long-term life expectancy to determine
how these factors interact in positive and negative frames. We also
measured ratings of option quality and perceived riskiness. Risk
aversion predominated in both frames, but framing effects also
occurred.
- 2:15-2:35
- Effects of Task Sequence, Difficulty, and Type on Probability
Judgments.
Thomas S. Wallsten & Hongbin Gu (U. of North Carolina, Chapel Hill)
Following training,
respondents estimated probabilities regarding from which of two a
priori equally likely equal-variance normal distributions
observations were drawn. Task difficulty varied within
respondents (hard, d' = 1, vs. easy, d' = 1.75) and task sequence
varied between. The hard-easy effect was strongly moderated by
sequence, due to carryover of response-criterion settings. The
subjective estimates in this and related tasks depended on sample
likelihood ratios. In contrast, they depend on distance from a
neutral point in general knowledge tasks.
- 2:40-2:50
- Decision Making and Affective Experience in Mathematical
Problems.
Michel Cabanac (U. Laval) &
Jacqueline Guillaume (U. of Grenoble)
This
study measured the affective experience of 12 subjects reading
correct and incorrect versions of 50 mathematical short problems
(Questionnaire I) including 200 items. This was followed by a
multiple-choice mathematical test with the 50 problems
(Questionnaire II) using the same 200 items and offering the correct
and incorrect answers. Subjects tended to choose correct as well as
incorrect responses corresponding to their highest affective rating
within each problem. In all cases the subjects' behavior was higher
than chance level, and thus, followed the trend to maximize
pleasure. This result supports the hypothesis according to which
the key to decision making lies in the affective dimension of
conscious experience.
- 2:55-3:10
-
On-Line Hypothesis Evaluation: Number of Hypotheses,
Number of Hypothesis Changes, and Individual Differences in
Working Memory.
Eric G. Freedman, Paul Britton,
Matthew Woodruff, & Raymond Vernagus
(U. of Michigan, Flint)
High and low working memory
(WM) individuals evaluated a single or pair of hypothesis by
viewing seven pieces of evidence resulting in two, one, or zero
hypothesis changes. Next, subjects decided which final hypothesis
was correct. As the hypothesis changes increased, low WM
individuals exhibited a relatively greater increase in reaction times
and a relatively greater decrease in accuracy than did high WM
individuals. High WM individuals were faster and more accurate
than low WM individuals.
- 3:30-5:25
- Psychonomic Society: J/DM III (Grand Ballroom B)
- 3:30-3:50
- Evaluating a Class of Utility Theories.
Richard A.
Chechile & Sue F. Butler (Tufts U.)
A wide class
of utility theories can be subsumed under the Miyamoto (1988)
generic utility formulation. Chechile and Cooke (1997) tested this
utility framework by measuring model-dependent scaling
parameters. One of these parameters should be invariant if the
generic utility theory is valid. However, that parameter
systematically varied. The present study resolves a methodological
problem with the Chechile and Cooke experiment, and still results
in finding evidence contradictory to the generic utility theory.
- 3:55-4:15
- Confidence in Aggregation of Expert Opinion
David V.
Budescu & Adrian K. Rantilla (U. of Illinois,,
Champaign)
Two studies examined how different configurations
of expert opinions affect decision-maker confidence. In Study 1,
confidence was higher when experts saw the same information,
when fewer experts gave opinions, and with higher expert opinion
values. Study 2 replicates Study 1 findings, and also suggests that
confidence increases as the range of expert opinions (amount of
expert disagreement) decreases. These results are discussed within
the general framework of aggregation of expert opinion.
- 4:20-4:40
- Cue Priorities in Making Risky Choice
X. T. Wang (U. of South Dakota)
Decision makers often use social and
verbal cues in choice problems according to predetermined
priorities. We investigated how this ordering is related to domain-
specific social factors and ecological validity of the cues. In our
study of risk preference, cues of kinship, anonymity, group size,
group constitution, and verbal framing were used by participants in
decreasing priority. This ordering from more to fewer social cues
affects aspiration levels of a decision maker and consequent risk
preferences.
- 4:45-5:00
- The Nature of Adaptive Decision Making Under Presentation
Constraints.
Douglas H. Wedell & Stuart M. Senter
(U. of South Carolina)
We examined accuracy, effort, and
strategy differences in a task in which participants viewed sets of
apartments described along four dimensions. Sets were designed
to identify strategies from choice or judgment patterns.
Information was presented by alternative or by dimension.
Consistent with the adaptive decision-maker hypothesis,
dimensionwise participants were more efficient (higher accuracy,
reduced looking times), but greater efficiency in choice was not
due to different strategy use. Strategy differences were found in
judgment.
- 5:05-5:20
- Generalization of PMM Therapy to Polychotomous Cues
David Slegers, Gregory L. Brake, & Michael E.
Doherty (Bowling Green State U.)
Gigerenzer et al. have explored their PMM approach to
decision making, which posits a noncompensatory decision rule
based on only one cue, but PMM applies only to dichotomous
cues. We extend it to the case of polychotomous cues, employing
an analogy to the limitation on the number of categories people use
in making absolute judgments (Miller's 7 +- 2). The 7 +- 2 model
correctly predicts nearly as well as a regression model using all of
the predictor variables.
Sunday, Nov 22
- 8:30-9:00
- Registration & Continental Breakfast
- 9:00-10:40
- Symposium: Interactive Judgment and Decision Making Symposium
Organizer: Derek J. Koehler (U. of Waterloo)
- Theory and Research on Uncertainty and Behavior in Judge Advisor Systems
Janet A. Sniezek (U. of Illinois at Urbana-Champaign)
A Judge Advisor System is a set of persons participating in
a decision process in different roles: the Judge is
responsible for the final decision and may solicit or receive
advice from one or more Advisors. It is argued that most
important decisions are made by JASs rather than
individuals or groups, and that the decision processes of
JASs differ from those of groups or individuals in critical
ways. Theory and research on the unique aspects of JASs
will be discussed, with an emphasis on information search,
cognitive and goal conflict, and confidence assessments.
- Evaluation Errors in Interactive Decisions: When Evaluators Perceive Others To Be Too Conservative
Chip Heath (Duke U.), Marc Knez
(U. of Chicago), & George Wu (U.
of Chicago)
We study situations where an outside view may cause
outsiders to inappropriately perceive insiders as too
conservative. In two studies, targets answered open-ended
questions and provided cash equivalents (CEs) for their
answers; "outside" evaluators also provided CEs for the
target's answers. In a low knowledge condition, targets
provided lower CEs than evaluators. Target's CEs were more
accurate than evaluators' (calibration and resolution were
superior), but, in a social perception task, evaluators
rated targets as being overly conservative. Outside judges,
when they have a less complex view of the world, may
incorrectly evaluate inside advisors as being overly risk-
averse or conservative.
-
Social Influence Under Uncertainty: Effects of
Evaluating Typical and Extreme Advice on
Confidence
Kristine M. Kuhn (Princeton U.), David
Spurlock (U. of Illinois at Urbana-
Champaign), & Janet A. Sniezek (U. of
Illinois at Urbana-Champaign)
Two experiments on the impact of considering advice for a
task with high uncertainty long-range forecasts of global
events are presented. In the first, subjects were given
anonymous forecasts (advice) that were either typical or
very unusual and wrote either supporting or contrary
reasons for their advisor's forecasts; the two manipulations
had interactive effects on subjects' confidence in their own
subsequent forecasts. Results of the second experiment
indicate that different degrees of effort engendered by the
experimental manipulations best explain their effects on
confidence. Social influence as a source of alternative
decision hypotheses and the complexity of assessing effects
in real-world settings are discussed.
-
Unintended Influence of Exposure to Another's
Hypothesis on Confidence and the Generation of
Alternative Hypotheses
Derek J. Koehler (U. of Waterloo)
Two experiments demonstrate that exposure to somebody
else's hypothesis induces an anchoring effect on the
generation of alternative hypotheses. Although such an
influence can be rationally justified by treating the person's
hypothesis as relevant information, results of the present
experiments suggest that the anchoring effect may not be
entirely deliberate. Instead, people apparently misattribute
the resulting similarity between their own hypothesis and
that of the person's to which they have been exposed as
evidence of accuracy. As a result, generation of alternative
hypotheses following exposure to that of another person
can have an unintended biasing influence on subsequent
confidence assessments.
- Symposium: Decision Analytic Concepts Applied to
Prostate Cancer Screening and Treatment
Decisions: Progress and Prospects
Organizer: Robert M. Hamm
(U. of Oklahoma Health Sciences Center)
Speakers:
- Robert Hamm, PhD. (U. of Oklahoma Health
Sciences Center) Introduction.
- James Mold, MD (U. of Oklahoma Health Sciences
Center)
Although prostate cancer screening is often viewed as a
great benefit for all men, in fact it can be a trap for the
physician and for the patient. Prostate cancer grows slowly,
and it often would be appropriate for men with a short life
expectancy (less than a decade) not to treat it (by removing
the prostate) but instead to live with it. However, many
patients, who would choose not to treat, are nonetheless
interested in getting a prostate cancer screening test.
Doctors who recognize there is no point to screening for
such men often gamble (hoping that the test will be
negative) rather than trying to convince the patient that it
would be better not to know. Is there a better way to
communicate with patients about the risks and benefits of
screening?
- Michael W. Kattan, PhD (Baylor College of Medicine)
Decision analysis of the decision whether to treat a cancer
discovered by screening (and deemed treatable) takes into
account both the predictable side effects (postoperative
morbidity, incontinence, impotence) and the anticipated
increase in life expectancy. Markov analysis lets the
analysis take account of quality of life at various points in
the future. The decision is sensitive to individual patient's
preferences for living with the side effects. The decision
analytic model can be individualized for patients, who can
visit a web site, complete a utility assessment regarding
incontinence and impotence, and be given a
recommendation whether they should get treatment.
Problems inherent in keeping a decision theoretic model up
to date will be discussed.
- Scott Cantor, PhD (MD Anderson Cancer Center,
U. of Texas)
There have been two decision analyses of the decision
whether to screen for prostate cancer, one evaluating a
single screening, the other evaluating annual screening.
Logically, each includes the decision whether to treat
(described by Kattan), and adds considerations of the
reassurance provided by a negative screen as well as the
anxiety induced by knowing one has a cancer, especially
pertinent for those who will opt not to treat. Problems of
integrating evaluations of time limited anxiety with
evaluations of death and long term quality of life are
discussed.
- Robert J. Volk, PhD (Univ of Texas Medical Branch at
Galveston)
Whose utilities count? The majority of men in whom
prostate cancer is discovered are married. The wife would
share in the outcomes of any decision, including
incontinence and impotence. A study of husbands' and
wives' evaluations of these outcomes showed large
differences within the couples. Generally, women were
more willing than their husbands to risk longterm
incontinence and impotence to increase the husband's
expected life span. Problems of integrating discordant
spousal preferences are discussed.
- Robert Hamm, PhD. (U. of Oklahoma Health
Sciences Center)
How may we assist men in making rational decisions
(decisions consistent witht their values) regarding prostate
cancer screening? Tools proposed for presenting decision
relevant facts for medical decisions (probabilities of
outcomes, evaluations of outcomes) are described. Issues
to be discussed include that presentation of all the facts is
unbiased but perhaps difficult to comprehend, while
presentation of vivid examples is memorable and
influential but may be biased.
- 10:40-11:10
- Break
- 11:10-12:25
- Paper Session
-
The Springs of Action: Affective and Analytical
Information Processing in Choice
Ellen Peters & Paul Slovic (U. of Oregon and
Decision Research)
Affective processes are predicted to play a critical role in
the construction of choices. In two studies, we successfully
used paper-and-pencil measures of individual differences in
affective information processing to predict choices in a card
selection task modified from Damasio (1994). The results
were particularly strong when the processing of rewards
and punishments were considered separately. Individual
differences in analytical information processing did not
relate to choice as predicted. While society has valued
analytical, deliberative thought more than other emotional
ways of knowing, affect, in interaction with analytical
thought, appears to strongly influence decisions and
judgments.
-
Is It True Bronze Medalists Have More Fun?
A. Peter McGraw & Barbara Mellers (The Ohio State
U.)
Medvec, Madey, and Gilovich (1995) claimed that bronze
medal winners in the 1992 Summer Olympics appeared
happier than silver medal winners, due to systematic
upward and downward counterfactual comparisons. We
investigate the effects of prior expectations in a series of
laboratory and real-world experiments. We find that people
tend to make upward counterfactual comparisons when
judging the most likely alternative outcomes. We also find
that prior expectations have strong effects on perceived
happiness. Finally, we examine the effect of prior
expectations on athlete's emotions in the 1996 Summer
Olympics and compare our findings to those obtained by Medvec
et al.
-
The Impact of Negative and Positive Affect on Managers'
Risky Decision Making
Kimberly Moreno (Virginia Polytechnic Institute and State
U.), Thomas Kida (U. of Massachusetts at
Amherst), & James F. Smith (U. of Massachusetts
at Amherst)
This study examines the impact of affective reactions on
managers' risky behavior in both gain and loss contexts.
We propose that an affective reaction's underlying negative
or positive valence is the critical factor influencing decision
behavior. The findings indicate that affective reactions to
data within a decision context can result in risk taking for
gains and risk aversion for losses, contrary to the
predictions of prospect theory. Since this research was
conducted on experienced corporate managers, the study
demonstrates the importance of affect in expert decision
making. The results also indicate that affect influences
experienced managers to choose alternatives with lower
economic value, suggesting that managers consider both
financial utility and the utility of affect when evaluating
risky alternatives.
- Paper Session
-
'Learning' With No Feedback: A Test of Belief and Choice
Reinforcement Models in Games
Roberto Weber (California Institute of Technology)
Theories of learning in games map a history of observed
outcomes into choices. These theories are inconsistent with
the possibility that behavior in games may systematically
change as a result of factors other than experienced
outcomes. This paper uses the p-Beauty Contest game to
test the assumption that learning mainly takes place through
reinforcement. The main experimental treatment is a no-
feedback condition, in which outcomes are not reported to
the players until the end of the experiment. Traditional
models of learning predict that there should be no
convergence towards the Nash equilibrium. Preliminary
results indicate some convergence towards the equilibrium.
-
The Development of Expertise in Decision Making
Ilan Fischer (Ben Gurion U. of the Negev, Israel)
This study traces the utilization of decision strategies, as a
decision-maker develops expertise in a given domain. The
study is driven by a Cognitive Clasification Structure
(CCS) model, which distinguishes between three operation
modes: Screening, Discrimination and Classification.
The amount and structure of the information that is processed
and utilized for decision making varies systematically across
the three modes. In two experiments, 180 subjects performed
a repeated categorical decision task with feedback. Subjects
participated in six sessions of 300 decisions each. The
findings reveal a dynamic use of all three CCS processes.
The most frequently used decision
mode is the Discrimination process. The ratio between
Classification and Screening gradually changes as the DM
gains more experience.
-
Psychological Space of Decision Similarity and Its
Influence on Decision Strategies
Yuri Tada & Elke U. Weber (The Ohio State U.)
In exploring factors that determine the choice of decision
strategies in everyday decision making, knowing how
people categorize those decisions would be useful. If
people are indeed adaptive decision makers who select
strategies in a systematic fashion, there must be in their
mind some representation of the similarity between
decisions. Using multidimensional scaling, we found two
different three-dimensional configurations, depending on
whether participants were instructed to sort decisions in
terms of unspecified "similarity" or in terms of "similarity
in making these decisions." A subsequent study indicated
that these dimensions indeed appeared to influence the
selection of different decision strategies.
- 12:25-1:30
- Lunch
- 1:30-2:00
- Einhorn Award Address, Einhorn Award Winner
announced and introduced by Eric J. Johnson
- 2:00-3:00
- Invited Address by Robert Winkler (Duke U.):
Combining Forecasts
- 3:00-4:30
- Poster Session I
- 4:30-5:45
- Paper Session
-
On Evaluation Goals and Sequential Order Effects: The
Relationship between Hedonic and Informational
Evaluation
Gal Zauberman (The Fuqua School of Business, Duke
U.) & Dan Ariely (The Sloan School,
Massachusetts Institute of Technology)
This paper examines the effect of the sequential order of
information on the final evaluation under two evaluation
modes, Hedonic and Informational. The main thesis of this
paper is that the Evaluation-Goal impacts the integration
rules, and thus the observed sequential order effects. The
prediction is a stronger primacy effect under informational
evaluation, and stronger recency effect under hedonic
evaluation. In two experiments subjects were asked to
evaluate identical sequences of information (ascending and
descending) under each evaluation goal. The hypotheses
were supported in both experiments. That is, there was an
interaction between the Evaluation-Mode and the ascending
and descending patterns. The exact pattern of results
differed between retrospective and predictive evaluations.
-
The Relationship Between Time Constraints and Time
Pressure
Lehman Benson III, Markus Groth, & Lee Roy Beach
(U. of Arizona)
Time constraints and time pressure often are often used
interchangeably. We suggest that this is incorrect, and
differentiate between the two, conducting four experiments
designed to examine the relationship between time
constraints and feelings of time pressure. The literature,
and common sense, both suggest that three factors
influence the perception of time pressure (1) the time
available, (2) the time required, and (3) the importance of
the task (motivation). The first two experiments involved a
laboratory task in which subjects were told both the time
required to do a hypothetical task (Rr) and the time
available to do it (Ra). Experiments 3 and 4 involved a
task in which subjects solved arithmetic problems for pay.
Implications for past and future research on decision
making under time pressure are discussed.
-
When the Pleasure of Winning Exceeds the Pain of Losing
Jeff T. Larsen & Barbara A. Mellers (The Ohio State
U.)
Prospect theory holds that equal probability gambles to win
or lose some amount of money should be avoided, even
when stakes are low. In Experiment 1, however, when
presented with gambles to win or lose $0, $1, $3, $6, $12,
$25, $50 or $100, participants' preferences peaked at $6,
rather than $0. In another experiment, participants
presented with the $0, $1, $3, $6, and $12 gambles
preferred the $3 gamble; those presented with the $0, $12,
$25, $50, and $100 gambles preferred the $25 gamble.
These and data from two other experiments suggest a desire
for gambles of intermediate value.
- Paper Session
-
Judgment under Sample Space Ignorance
Michael Smithson (Australian National U.),
Thomas Bartos (Australian National U.), &
Kazuhisa Takemura (Tsukuba U.)
Although the incorporation of 'ambiguity' in decision
research is now fairly commonplace, little attention has
been paid to how people judge probabilities or make
decisions under sample space ignorance, i.e., knowing what
all possible outcomes are. Walley (1991, 1996) has
developed an imprecise probability framework for
probability inference that begins with vacuous lower and
upper probabilities when the sample space is completely
unknown, and then updates those estimates as evidence
becomes available. This paper presents findings from six
studies that investigate aspects of Walley's framework in
combination with related behavioral research and theories
of judgment under ambiguity.
-
A Good Chance Is Not a Number: Determinants and
Implications of Verbal Probabilistic Terms
Karl Halvor Teigen (U. of Tromso, Norway)
Verbal probability phrases are of two distinct kinds:
Positive ('possible', 'a good chance') and negative ('not
certain', 'doubtful'). Positive phrases focus on the
occurrence of a target event, whereas negative phrases
focus on its non-occurrence. This makes them different
from numerical probabilities, which can be given both
positive and negative interpretations, dependent upon
context. Thus verbal probabilities are, in one sense, less
ambiguous than numbers. The directionality of verbal
phrases can be shown to have consequences for predictions,
decisions, and probabilistic inferences (e.g. the conjunction
fallacy). Verbal probabilities (in contrast with numerical
estimates) are strongly affected by closeness of the target
outcome.
-
The Interpretation of "Likely" Depends on the Context, But
"70%" is 70%--Right?: Associative vs. Rule-Based
Processing of Uncertainty Information
Elke U. Weber (The Ohio State U.) & Paul D.
Windschitl (U. of Iowa)
Past research demonstrates that interpretations of verbal
uncertainty forecasts ("likely") depend on the context to
which they refer, presumably as the result of rule-based
mental processes and the vagueness of verbal expressions.
Three experiments demonstrate that precise numeric
forecasts ("70%") are also susceptible to context effects.
We show that associative rather than rule-based processing
of uncertainty information best explains why perceptions of
uncertainty vary with context even when precise and
credible numeric forecasts are provided. We discuss the
implications of the fact that uncertainty information appears
to be processed within two semi-independent processing
systems, one associative and the other rule-based.
- 5:45-7:15
- Poster Session II and Reception
Monday, Nov 23
- 8:00-9:00
- Business Meeting & Continental Breakfast
- 9:00-10:40
- Paper Session
-
"That's the Best You Can Do?" When Negative Evidence
Increases Confidence
Craig R. M. McKenzie, Susanna M. Lee, & Karen K. Chen
(U. of California at San Diego)
Using a legal scenario, three experiments examined change
in confidence following presentation of each of two sides of
a dispute. We argue that change does not depend simply on
a case's strength, but on the difference between its strength
and its minimum acceptable strength. A case can fall
below this level and increase confidence that the competing
account is most accurate. Furthermore, the minimum
acceptable strength of the second case is influenced by the
strength of the first case. Case strength is evaluated relative
to a non-zero reference point because it is understood that a
case represents a biased sample of available evidence.
-
Priming for Expertise and Confidence in Choice:
Evaluating the Global Improves Calibration for the Specific
Oleksandr S. Chernyshenko & Janet A. Sniezek (U.
of Illinois at Urbana-Champaign)
It is well-known that item-level confidence is higher than
more general self evaluations for difficult decision tasks.
But can the latter debias the former? Participants provided
choices and confidence assessments for items from 20
different knowledge areas. For some items, participants
rated their expertise in the area before seeing the item. This
priming for expertise improved calibration, with less
overconfidence on difficult items as well as less
underconfidence on easy items. The direction of the item
bias reduction is consistent with a dual-source explanation
of the over/underconfidence phenomenon. Theoretical and
practical implications of the observed reduction in
miscalibration are discussed.
-
When Knowledge is a Bad Thing: Empirical
Demonstrations of Less-Is-More Effects
Daniel G. Goldstein (Harvard U.)
This talk presents a challenge to the view that more
information is always better than less for the quality of
inferences. Focusing on two-alternative inferences made from
multiple cues, it is shown that the addition of valid,
predictive information can decrease inferential accuracy in
natural and artificial systems. This phenomenon, deemed the
less-is-more effect, was discovered as a consequence of the
simple recognition heuristic for inference. Three empirical
demonstrations of less-is-more effects are presented. The
most challenging of these makes the prediction, contrary to
intuition, that knowledge test scores should decrease with
repeated testing due to a "false fame" effect.
-
Familiarity Bias in Relative Likelihood Judgment
Craig R. Fox & Jonathan Levav (Duke U.)
Probability theory and most descriptive models of judgment
under uncertainty imply that belief orderings over events
and their complements should mirror each other (e.g., H is
more likely than L iff not-L is more likely than not-H).
This principle is violated in several surveys in which we
asked people to assess the relative likelihood of familiar
versus unfamiliar events. In particular, respondents are
biased to view familiar events (and their complements) as
more likely than unfamiliar events (and their complements).
Further studies suggest that the familiarity bias may be less
pronounced among subjects who are asked to judge the
probability of each event rather than which event is more
likely.
- Paper Session
-
Taking One for the Team: Group Utility and Personal
Dissatisfaction
Jonathan Levav (Duke U.) & Dan Ariely (MIT)
Many individual decisions, such as what dish to choose in a
restaurant, take place in a group context wherein group
members voice their choices sequentially. In this paper we
examine the impact of this dynamic decision process on
individuals' choices and satisfaction with their outcomes.
We propose that group members alter their decisions
contingent upon the choices of other members, yielding a
pattern of variety-seeking on the group level. This group
contingency sometimes results in choices that undermine
personal satisfaction and increase regret. We find support
for our hypotheses in one pilot study and two field studies
where we tracked consumers' order of dishes and drinks.
-
Initial Evaluation of Integrative Offers in Multi-Issue
Negotiations
Simone Moran & Ilana Ritov (Ben-Gurion U.,
Israel)
This research examined evaluation of initial offers by
inexperienced negotiators. Our findings suggest that (a)
Due to coding of values as gains or losses relative to the
"even split" reference point, integrative offers appear less
attractive than distributive offers. (b) Although receiving
integrative offers may improve understanding of one's own
profit schedule, it does not lead to better understanding of
mutual interests. (c) The composition of counteroffers
depends upon the composition of initial offers. We
conclude by proposing that integrative offers may be
beneficial to the initiator, not due to any social message
they presumably convey, but simply because they establish
within-issue advantageous anchors.
-
Theories of Commitment, Altruism and Reciprocity:
Evidence from Linear Public Goods Games
Rachel Croson (U. of Pennsylvania)
Theories of commitment, altruism and reciprocity have all
been invoked to explain and describe observed behavior in
public goods and social dilemma situations. In particular,
commitment theories have been used to explain behaviors
like water conservation and voting. Theories of altruism
are applied in explanation of contributions to charities and
intergenerational transfers and bequests. Theories of
reciprocity have been invoked to explain gift exchange and
labor market decisions. This paper describes a set of
experiments which distinguish between these competing
theories by testing their comparative statics predictions in a
linear public goods setting. Results provide strong support
for reciprocity theories over either theories of commitment
or of altruism.
-
Cross-National Differences in Risk Preference
Christopher K. Hsee (The U. of Chicago) & Elke
U. Weber (The Ohio State U.)
A series of studies using different methods show a
consistent cross-national difference in choices under risk
that the Chinese were less risk averse than the Americans.
Yet when asked to predict the choices of their counterparts
in the other country, both American and Chinese
respondents predicted that the Chinese would be more risk
averse. The cross-national difference in risk preference is
explained by a "cushion" hypothesis which suggests that
people in a collectivist society, such as China, are more
likely to receive help if they are in need (i.e., they could be
"cushioned" if they fell), and consequently, they are less
risk-averse.
- 10:40-11:10
- Break
- 11:10-12:10
- Invited Address by Alvin E. Roth (U. of
Pittsburgh):
Towards a Cognitive Game Theory
- 12:15-1:45
- Luncheon
Student Poster Award Winner announced by Sandra L.
Schneider
Presidential Address by Elke U. Weber (The Ohio State
U.), "From Shakespeare to Spielberg (with apologies
to Paul Slovic): Some Reflections on Modes of Decision
Making." Introduced by Irwin P. Levin, President-Elect.
- 1:45-3:25
- Symposium: On Mice & Men: Effects of
Sequences' Characteristics and Duration
Organizer: Dan Ariely (MIT)
-
Temporal Integration and Duration Neglect in the
Evaluation of Rewarding Brain Stimulation by Laboratory
Rats
Peter Shizgal & Bonnie Sonnenschein (Center for Studies
in Behavioral Neurobiology, Concordia U.)
In the evaluation of temporally extended experiences,
certain salient features, such as peak value, terminal value,
and slope, appear to play a privileged role. To predict the
effect of changing the temporal profile of an experience on
its remembered value, the weighting of different features
must be described and the rules employed in processing
them understood. One approach to this problem takes
advantage of the tight control over intensity and duration
afforded by direct electrical brain stimulation in laboratory
animals. When delivered to appropriate brain sites, such
stimulation can be intensely rewarding; rats can be trained
readily to initiate such stimulation, and their performance is
tied closely to its temporal and spatial parameters. We
have developed and tested a model that links the subjective
intensity of the rewarding effect to stimulation strength and
duration. Intensity is modeled as a logistic function of
stimulation strength; the input strength required to produce
a half-maximal intensity declines hyperbolically with
duration. A simple peak rule, which suffices to account for
existing data, is employed to translate the real-time profile
into a stored record. As predicted by this model, the
recorded intensity increases initially with duration but
eventually levels off; the higher the stimulation strength,
the shorter the time required for the intensity of the
rewarding effect to approach asymptote. Beyond this
critical time, duration is neglected. The implications of
these and related results for the study of intertemporal
choice in humans will be discussed.
-
Intensities and Intensity Changes: The Impact of Memory
and Distraction on Encoding of Sequences' Characteristics
Dan Ariely (MIT)
The emerging literature on the evaluation of sequences has
convincingly demonstrated that when people summarize
experiences they do not simply combine (integrate) the
intensity of their actual experiences. Instead, decision
makers extract only a few key aspects of these sequences
(gestalt characteristics), and it is these gestalt
characteristics that are than used to form overall evaluations
of the sequence as a whole. The current work examines the
relative role of a few of these gestalt characteristic. Two
general classes of characteristic are examined, one that is
based on the actual intensities of a sequence and one that is
based on the relationships between intensities over time. In
addition, we examine the impact of delay and distraction on the
relative impact of these two types of characteristic. The
results show that the relationships between intensities over
time (i. e. slop) plays a large role on both retrospective and
prospective evaluations. In fact its role is so large that
evaluation sometimes violate dominance relationships
between the sequences. Finally, the role of the transient
intensities even increases with delay and distraction.
-
Encoding Sequences and Conveying Information in Ratings
and Choice: The Case of Sequences' Characteristics and
Duration
George Loewenstein (Center for Advanced Study in the
Behavioral Sciences)
Recent research shows that people's evaluations of
temporally extended experiences do not correspond to a
simple integration of pleasure and pain over time but are
sensitive to a few key features of the experience, such as
improvement or deterioration over time, and peak and end
levels. In this line of research, a provocative assertion,
made first by Fredrickson and Kahneman (1993) is that
duration is a feature that is not incorporated into such
evaluations, a pattern which was labeled "duration neglect."
Duration neglect is of great potential significance since it
can, in principle, produce severe choice anomalies such as
violations of dominance. The vast majority of studies
examining duration neglect have not, however, examined
choices between extended experiences, but rather ratings of
such experiences. We argue that ratings can sometimes be
a biased measure for studying whether duration is neglected
in choice, for reasons that relate to norms in decision
making (Kahneman & Miller, 1986) and conversational
norms (Grice, 1975). We demonstrate the problem with
ratings with two parallel studies in which subjects
retrospectively evaluate sequences of aversive sounds, one
in which subjects rated the sequences, and the other in
which they chose between them. Our major finding that
duration neglect is more pronounced in the rating condition,
but less so in the choice condition raises questions about
the conditions under which duration neglect observed in
ratings actually leads to duration neglect in choice.
- Symposium: Legal Applications of J/DM Research
Organizer: Russell Korobkin
(U. of Illinois College of Law)
-
The Status Quo Bias and Contract Law
Russell Korobkin (U. of Illinois College of Law)
Standard legal analysis of contract "default rules," that is,
rules that govern a relationship between contracting parties
only if the parties fail to specify their own preferred terms
suggests that if the costs of bargaining are low, the content
of default rules will matter little. This paper demonstrates
that, in certain circumstances, contracting parties will view
the default rules as part of the status quo, and will thus be
reluctant to contract around these rules even when the costs
of bargaining are low. Thus, default rules are "stickier"
than previously thought. The paper then addresses the
question of how, in light of these results, policy makers
should determine the content of default rules.
-
Judging in Hindsight
Jeff Rachlinski (Cornell Law School)
The "hindsight bias" affects judgments of liability in the
legal system. The bias makes adverse outcomes seem more
predictable than they really were, and as a consequence
defendants can be held liable for adverse outcomes that they
could reasonably believed to have been unlikely. The legal
system, however, seems to be aware of the bias and has
adapted well to its influence. When possible, courts have
developed methods of making judgments that avoid reliance on
the hindsight bias. Nevertheless, there are as yet untaken
adaptations that the courts could pursue to ameliorate the
influence of the bias further.
-
The Scales of Justice: The Effect of Cap Magnitude on the
Likelihood of Settlement
Linda Babcock (Heinz School of Public Policy &
Management, Carnegie-Mellon U.)
A major issue in the current debate over litigation reform is
whether to limit the amount of damages plaintiffs can
receive. This paper conducts a series of experiments to
explore the behavioral mechanisms by which damage caps
affect the prospects for settlement. Our results indicate that
when the damage cap is relatively low, it increases the
likelihood of settlement. However, preliminary evidence
suggests that a very high damage cap can actually reduce
the prospects for settlement by providing plaintiffs with an
upward "focal point". This implies that in a particular state,
a cap statue will improve settlement rates for big cases and
worsen them for small cases.
-
When Are Jurors Impressed By Probabilistic Evidence?
Jonathan J. Koehler (U. of Texas at Austin)
The way in which probabilistic evidence is presented to
legal factfinders can have a profound impact on the
perceived strength of that evidence. This study shows that
presentations of DNA statistics that call attention to the
number of others in a reference population who would also
match by coincidence tend to weaken the perceived value
of the evidence. Presentations that focus on the target
suspect's small coincidental match probability without
reference to others who would also match by coincidence
tend to strengthen the perceived value of the evidence. For
example, in one hypothetical murder case that included
DNA match evidence, many subjects believed that there
was more than a 99% chance that the suspect was the
source of the DNA evidence. But when the match statistic
was presented in a slightly different (but accurate) way,
nearly as many subjects believed that there was less than a
1% chance that the matching suspect was the source when
the evidence! A general theory will be offered.
- 3:25
- Adjourn