London Judgment & Decision Making Group
Autumn term 2015 – 2016
Organizer
Neil Bramley
University College London
Contact details:
Department of Cognitive, Perceptual & Brain Sciences
Room 201, 26 Bedford Way, London, WC1H 0AP
UK
Telephone: +44 (0) 79 1441 9386
E-mail: neil.bramley@ucl.ac.uk
LJDM website
http://www.ljdm.info
LJDM members’ (Risk & Decision) list
https://www.jiscmail.ac.uk/cgi-bin/webadmin?A0=RISK-AND-DECISION
Seminar Schedule
October – December 2015
Wednesdays, 5:00 pm in Room 313, 26 Bedford Way, UCL Psychology
7th October
What drives “Unconscious” Multi-Attribute Decision-Making?
Eddy Davelaar
Birkbeck, University of London
14th October
Time compounding not time discounting
Philip Newall
University of Stirling
21st October
Presenting Bayesian problems to a general audience
Stephen Dewitt
Birkbeck, University of London
28th October
Staying afloat on Neurath’s boat: A new theory of theory change
Neil Bramley
University College London
4th November
Justifying unpopular climate policies: The argument from moral error and
moral expertise
Felix Pinkert
University of Warwick
11th November
READING WEEK (NO SEMINAR)
18th November
Designing for the Psychology Underpinning Behaviour Change
Anne Hsu
Queen Mary, University of London
25th November
A Model of Factors that Shape Cancer Screening Decisions
Dafina Petrova
University of Granada / Imperial College London
2rd December
Situating a Bayesian source credibility model: initial explorations of public
health campaigns and election candidates
Jens Madsen
Birkbeck, University of London
9th December
Game show economics
Martjin van den Assem
Vrije Universiteit Amsterdam
16th December
The flexibility of moral intuitions
Jonas Nagel and Alexander Wiegmann
University of Göttingen
Abstracts
07.10.2014
What drives “Unconscious” Multi-Attribute Decision-Making?
Eddy Davelaar
Birkbeck, University of London
This study aims to further investigate the Unconscious Thought Theory (UTT, Dijksterhuis &
Nordgren, 2006), namely whether individual differences account for differences in choice made
after either deliberation (conscious thought, CT) or distraction (“unconscious thought”, UT).
Subjective weighting was taken into consideration by providing choice options that were
constructed following individual preferences. Hence attributes match the subjective preferences,
which undermines previous critiques that results were distorted by differences between individual
and objective choice. The main effect was replicated with a big sample (N=120, CT: 50.8%, UT:
70.5% chose the best alternative), using four different dependent measures. This result is
remarkable insofar as Nieuwenstein and van Rijn (2012) in their meta-analysis only found an
effect when CT was at chance level. The results show further that the main effect is driven by
underperformance of women in the CT condition. Stereotype threat is discussed as a possible
explanation.
Dijksterhuis, A., & Nordgren, L.F. (2006). A Theory of Unconscious Thought. Perspectives on Psychological
Science, 1(2),
Nieuwenstein, M. & Van Rijn, H. (2012). The unconscious thought advantage: Further replication failures from a
search for confirmatory evidence. Judgment and Decision Making, 7(6), 779-798.
14.10.2014
Time compounding not time discounting
Philip Newall
University of Stirling
Intertemporal choice involves comparing prospects in different time periods. Instead of
discounting future values to present values, intertemporal choice can proceed by compounding
present values to future values. Maximizing compounded future value is equivalent to maximizing
discounted present value. Time compounding is presented as a more plausible model of processes
underlying intertemporal choice than time discounting models. Time compounding leads to
simple graphical analogues for impulsive behaviours. Linear extrapolation of growth in future
value is proposed to explain within-person variation in impulsiveness. Impulsive behaviour is
driven by linear overestimation of logarithmic value, and linear underestimation of exponential
value. Time compounding incorporates additional empirical regularities in decision-making.
21.10.2014
Presenting Bayesian problems to a general audience
Stephen Dewitt
Queen Mary, University of London
The ability to undertake Bayesian inference is becoming a necessary skill in modern society,
particularly within medicine and law. In medicine, doctors and patients need Bayesian inference
to make accurate assessments of the risk of a patient having a condition given several pieces of
evidence. In law, jurors are increasingly being presented with Bayesian calculations with the
expectation that they will be able to comprehend the information to provide a fair and accurate
judgement. However, both professionals and the public have been shown to make large errors in
Bayesian estimations. Two approaches have had success in improving accuracy on Bayesian
problems such as those faced by these groups: the ‘Nested Sets’ and ‘Causal’ framing approaches.
In a first paper, these approaches were combined and compared on a medical problem. Further,
participants were encouraged to document their thought processes while solving the problem
using a ‘write aloud’ protocol. An improvement in accuracy was seen for the nested sets framing,
but no effect was seen for the causal framing. From the ‘write aloud’ data a 4-stage model was
developed demonstrating the process that all successful individuals undertake. In a second paper
this nested sets framing approach was tested on a range of more ecologically valid problems and
was still found to improve accuracy. There are concerns that this approach will not be feasible in
legal situations due to its inherent focus on a single individual (the defendant), and so in a
prospective paper, this ‘problem of law’ will be tackled.
21.10.2014
Staying afloat on Neurath’s boat: A new theory of theory change
Neil Bramley
University College London
Over their lifetimes, people develop rich causal representations of the world that allow them to
understand and flexibly exploit their environment. People have been shown to be effective causal
learners, yet rational accounts of causal structure learning are intractable for all but the smallest of
toy problems. To account for this discrepancy, I propose a novel scalable process model of active
causal learning. The model is inspired by an old idea from philosophy of science about the
sequential and piecemeal nature of theory change, but also draws on current ideas from machine
learning, about sequential and approximate techniques for approximating Bayesian updating. I
will show that our model better captures the ways that people gather evidence and update their
causal beliefs than a range of alternatives in two causal learning experiments. Finally, I will
suggest that the model is not limited to the domain of causal structure learning, but is a candidate
explanation for the gradual evolution and adaptation of many types of theories in cognition.
04.11.2014
Justifying unpopular climate policies: The argument from moral error and moral expertise
Felix Pinkert
University of Warwick
If humankind is to avoid disastrous climate change, rapid and drastic changes to many aspects of
our economy and lifestyles are needed. Some policies that are needed to implement such changes
are going to be very unpopular, most notably if they incur non-monetary cost such as lifestyle and
land-usage alterations, and if such cost cannot be distributed equitably. This situation raises the
normative question of whether policy-makers are justified in even trying to implement such
policies, e.g. by using obfuscation, financial lock-in, and other means of insulating these policies
against democratic opposition. In this paper, I provide a justification of such policies on grounds
that opposition to these policies arises from a specific form of moral error that can justifiably be
compensated by moral experts.
In particular, I argue that the moral decision situation by posed climate change has several
features which undermine the quality of our everyday moral decision-making. I further contend
that moral philosopher's specific expertise is to understand and compensate for these distorting
features. Policies which are based on the advice of such moral experts then do not disrespect, and,
if coupled with education and social change, even enhance the autonomy of citizens. Because my
proposal rests on a highly specific understanding of moral expertise, it avoids justifying an
implausibly wide and intrusive range of ethics-driven policies.
11.11.2014
Reading week (NO SEMINAR)
18.11.2014
Designing for the psychology underpinning behaviour change
Anne Hsu
Queen Mary, University of London
Knowledge of the psychological constructs that underlie our actions offers valuable design
opportunities for behaviour change systems. I discuss three projects that aim to uncover these
constructs. First I will discuss how we applied decision theory based analysis in the domain of
weight management to understand the rewards and costs that surround individuals’ weight
management behaviours. Next, I will discuss a study that uses behavioural economics methods to
evaluate a major psychological cost of weight management: the perceived cost of effort for sitting,
standing, and walking. Finally, I will discuss a mobile app we designed to help people with the
psychological challenge of desire for excessive and unhealthy food. Our mobile app delivers a
food craving reduction intervention at the moment of need and allows users to track how often
they successfully resisted cravings. The craving reduction intervention used is based on recent
research that has found that food cravings can be reduced through imagery techniques. We
conducted a week-long evaluation of our app, comparing its effectiveness to a basic tracking
application. We found that our imagery application significantly reduced both overall snacking
and unhealthy snacking compared to a simple snack-tracking application.
25.11.2014
A Model of Factors that Shape Cancer Screening Decisions
Dafina Petrova
University of Granada / Imperial College London
Contrary to people’s intuitions, many cancer screenings have both benefits and harms. For
example, screening can reduce cancer mortality but result in many unnecessary surgeries.
Statistical information about such benefits and harms is sometimes provided to patients to foster
informed decision making. However, few models have addressed the role of comprehension of
such information in screening decisions. So how do people decide about screening when it is not
only good? How do they weigh in the evidence deemed relevant by experts? In three experiments,
we studied how several cognitive and emotional factors affect patients’ decisions. Our results
suggest that risk literacy (e.g., numeracy, science literacy) and a healthy dose of fear can promote
informed decision making. At the same time, emotions and beliefs reinforced by persuasive
campaigns can have strong effects on patients’ decisions beyond the available evidence. To
provide a more thorough picture of the decision environment, in a fourth experiment, we
investigate how physicians communicate about screening with their patients and what factors
shape their recommendations. Potential mechanisms (e.g., motivated cognition) and implications
for informed decision making will be discussed.
2.12.2014
Situating a Bayesian source credibility model: initial explorations of public health
campaigns and election candidates
Jens Madsen
Birkbeck, University of London
Bayesian models of source credibility have been explored conceptually (e.g. Bovens & Hartmann,
2003; Hahn et al., 2009) and tested empirically (Harris et al., in press), defining source credibility
as trustworthiness and epistemic expertise.
The talk discusses two concurrent aspects of the above model. Firstly, it applies the model to a
real-life situation. It tests the model against appeals to specific presidential candidates. Eliciting
estimations for all relevant aspects of the model, participants read a dialogue involving one of five
candidates (Sanders, Clinton, Rubio, Bush, and Trump) and rated how strongly they believed a
proposed policy to be good if that candidate publically had attacked/supported the policy.
Secondly, factorial analyses indicate that, like expertise, trustworthiness may be domain and
context-dependent (Madsen, submitted). Taking point of departure in analyses of doctors from
public health campaigns in the UK and Denmark, the concept of trust in the original model is
expanded to a multi-facetted concept (‘Ethical behaviour’, ‘Care for the health of all people’, and
‘altruistic diligence’ in the UK). This provides a test of a highly detailed and context-dependent
source description.
The talk provides indicative evidence that the general model tested in Harris et al. (in press) can
be applied successfully to more realistic argumentation scenarios (e.g. believing the goodness of a
policy if a trusted and expert election candidate advocates it) and more complex source depictions.
Although in its infancy and thus only indicative and tentative, the results point to interesting and
critical applications of the Bayesian source credibility model.
9.12.2014
Game show economics
Martijn van den Assem
Vrije Universiteit Amsterdam
Much of what we know about individual decision making to date derives from laboratory
experiments, and less so from real-life settings. Real-world data typically entail a lack of control,
which can make it difficult to discriminate between competing hypotheses. Carefully designed
laboratory experiments do allow for this and have generated a rich literature, but this approach is
also vulnerable to criticism about the generalizability of findings to situations beyond the context
of the lab. Because it is impossible to study behaviour under each and every possible set of
conditions, the optimal approach to assess the generalizability of existing findings is to study
behaviour in a limited number of diverging ways. The use of TV game shows is one of these.
Game shows allow the study of behaviour in a high-scrutiny field setting where the stakes are
high, and for a diverse subject pool. Combined with the strict and well-defined rules, game shows
can provide unique opportunities to investigate the robustness of existing laboratory findings. In
my talk, I will present my game show work on bargaining, risk taking, and cooperation.
16.12.2014
The flexibility of moral intuitions
Jonas Nagel and Allexander Wiegmann
University of Göttingen
Moral intuitions play an important role in philosophical and everyday moral discourse. Often they
serve as starting point or ultimate justification in moral arguments. In several different lines of
research, we demonstrate the pronounced context-sensitivity and flexibility of people’s moral
intuitions in response to concrete case descriptions. We conclude that the expressed judgments are
not well characterized as the accurate expression of stable underlying moral values, but rather
reflect the output of a highly flexible process of largely domain-general reason-based judgment
and choice.