The LJDM seminar series is supported by
University College London
City University London
Originally established at UCL in the early 1970’s as a weekly Cognition and Reasoning seminar, it later became an intercollegiate seminar on Language and Cognition in the early 1980’s.
The name LJDM was finally coined in 1990, and the group has been running seminars under this name ever since, with lecturers and researchers in and around the UK meeting on a regular basis to discuss judgment and decision making, judgments of likelihood, reasoning, thinking, problem solving, forecasting, risk perception and communication, and other related topics.
If you would like to present your research to the group or to suggest a speaker, please contact the organizers:
Unless specified otherwise, all seminars take place on Wednesdays at 5pm, in Room 313 at the Psychology Department, University College London (on the corner of Bedford Way, Gordon Square and Torrington Place, London WC1H 0AP). Map.
To get updates on the current schedule and weekly reminders of the seminars, please subscribe to the Risk and Decision mailing list.
All are welcome to attend.
Term 1 Seminar Schedule
October – December 2018
Hebrew University of Jerusalem
Time Course of Repeated Choice: The Effect of Experience on Choosers’ Well-Being
Whether choosing which cab company to order a ride from or whom to call to fix a leaking pipe, people often make repeated choices from a set of available options. Here, we explore how the valuation of options, choice outcomes, and the choosers’ well-being change with experience. We postulate a simple choice process in which every choice provides a noisy rendition of the option’s true value, an option’s valuation is updated in light of a new observation, and the highest-valued option is chosen again when another choice is required. We find that this process leads to a gap in the accuracy of valuations. While the valuation of the highest-ranked option remains accurate, all of the other options in the choice set become undervalued. As this gap in valuation increases with experience, many aspects related to the chooser’s well-being are affected. Confidence in one’s choice, product loyalty, and value maximization all increase; whereas the probability of being disappointed with the outcome of one’s choice and the probability of regretting that choice decrease. Robustness checks carried out by manipulating the noise level, the value-updating rule, the size of the choice set, and the shape of the parent distributions show that these effects hold across a variety of environmental conditions and processing assumptions. The comparisons involved in manipulating the set size and parent distribution also provide novel insights into the effects of choice overload and certain aspects of the relationship between the affluence of a society and the well-being of its members.
University of Leicester
Antimicrobial resistance: a social dilemma problem?
Antimicrobial resistance (AMR) is one of the greatest threats in 21st century medicine. AMR has been characterised as a social dilemma. A familiar version describes the situation in which a public good (in this case, antibiotic efficacy) is exhausted due to over-exploitation. The dilemma arises because individuals are motivated to maximise individual payoffs, although the collective outcome is worse if all act in this way. In the case of antibiotic use, the dilemma is further complicated by the lack of visibility and imminence of AMR, a loose coupling between individual actions and the outcome of AMR, and the agency relationships inherent in the prescriber role. Consequently, only a combination of theories of social dilemmas and agency relationships can provide an integrative theoretical framework to characterise antibiotic overuse fully. Drawing on these theoretical perspectives and on empirical data collected across three different countries (South Africa, Sri Lanka and UK), this talk will discuss different strategies for shifting prescriber behaviour and promoting a focus on the collectively desirable outcome of conservation of antibiotic efficacy.
Public support for government policies: the role perceived effectiveness, causal beliefs, and evidence
In an ideal world our policies would be based on the best available evidence for achieving the policy goal – be it tackling climate change, violent crime or obesity. A number of barriers exist that prevent or impede certain policies being implemented and this talk explores one in particular: the public’s support for the policy in question. By going through a series of recent experiments and a systematic review, this talk will highlight some key factors that determine how people’s attitudes toward the implementation of a policy are formed. This includes the role of perceptions of policy effectiveness and people’s beliefs about the causes of problems that the policy is trying to address. Both of these variables have been shown to predict support for the focal policy however the experimental studies which aim to change support present a mixed picture. The underlying question is do people change their beliefs when presented with evidence? And if so, do these changes in beliefs translate into more favourable attitudes toward the focal policy? The talk will answer these questions and discuss the psychological, health, and political implications.
Xiao Chuan Tong, Alexandru Preda, Andrew McFaull
The Cost of Sociability: Why Do Sociable Investors Persist in The Market While Making Losses?
Social trading platforms are still a relatively recent phenomenon, and little remains known about whether the introduction of non-market features within these platforms alters trading behavior. In this paper, we present evidence using survival analysis to show that the inclusion of social media features alongside traditional exchange functions does alter market dynamics by keeping unsuccessful traders in the market for longer. We focus upon the foreign exchange market, where numerous past studies have documented that the majority of retail traders lose money. Using our access to a unique dataset of 1,119,342 trader-day observations from 3,269 individual traders across an 18-month period, we show that sociable investors tend to persist much longer upon the platform and, as a consequence of this survivorship, lose more. Overall, our results indicate that the inclusion of social media features within trading platforms appears to be offering traders a form of non-monetary utility, which encourages investment and persistence in the market, but this social utility comes at a financial cost to the traders.
7/11/2018 READING WEEK (No Seminar)
London Business School
Causal beliefs in the representation of the self-concept and identity-based choice
I first investigate the age-old questions of what makes us who we are and what features of the self-concept, if changed, would make us a different person. Previous approaches to the self-concept have suggested that there is a type of feature that is most defining of identity (e.g., social categories, autobiographical memories, moral qualities). Inspired by research on conceptual representation, I propose a new approach to the self-concept that emphasizes causal beliefs. More specifically, that features are perceived as defining of the self-concept to the extent that they are seen as causally central, linked to many other features of the self-concept. Using both measured and manipulated causal centrality, I find that changes to more causally central features of the self-concept are perceived as more disruptive to self-continuity. I then examine the implications of this account of the self-concept for identity-based choice--do differences in beliefs about how an identity is causally connected to other aspects of the self-concept predict differences in identity-consistent choices? I provide evidence that people who perceive an identity (e.g., Democrat or Republican) as more causally central are more likely to act in identity-consistent ways (e.g., vote for their party’s candidate) than people who possess the same identity but perceive it as more causally peripheral.
Marwa El Zein
Regret and punishment in collective decision-making
In the last few decades, research on collective decisions has mainly focused on whether they are better or worse than individual decisions, but rarely on the motives that drive individuals to engage in group decisions. Besides improving accuracy, an important and less explored motive for individuals joining collectives is to protect themselves from negative decision outcomes by reducing internal (regret) and external (punishment) sanctioning. Here I will present results from studies that empirically addressed whether: 1) individuals join groups to anticipate and experience less regret during risky decision-making 2) collective decisions are punished differently from individual decisions for their norm violations using two well-known economic games, the ultimatum game and the dictator game with third-party punishment. This approach to collective decision-making tackles issues of regret, punishment and responsibility, and therefore has important implications across a wide range of societal domains, including medical decision-making and criminal justice.
University of Essex
Effect of insufficient information on patients’ expectations and requests for antibiotics in primary care
Interventions aimed at reducing patients’ expectations and requests for antibiotics focus on the provision of didactic information. Such interventions assume that patients lack information about diseases and antibiotics effectivity, but these are hard to evaluate in complex interventions. In two pre-registered studies, we first identify the dimensions of individuals’ beliefs about diseases and antibiotics that are associated with, and predict, expectations to receive and/or request antibiotics from a GP. Second, we examine the causal link between the provision of incomplete or imperfect knowledge about diseases and antibiotics from a GP and individuals’ expectations and requests for antibiotics.
We find evidence that the provision of information regarding the efficacy and side effects of antibiotics decreases, but does not diminish clinically inappropriate expectations and requests. The effect is small and partly depends on individuals’ prior beliefs. We observe no effect of information relating to the nature of the illness on expectations and requests. We suggest that interventions attempting to reduce expectations and requests should explore additional factors that will lead to a synergic effect.
Putting Cambridge Analytica to the test, can personality based framing influence persuasion for or against Brexit?
Part of the scandal around Cambridge Analytica centred on the idea that if you could identify someone’s personality from their online behaviour, then you might be able to better target political material that could be more persuasive to them. Whether or not this technique would have worked in the context of recent elections is however unclear. Personality based framing does seem to be effective in targeting certain online commercial advertisements, and there is evidence to suggest that moral re-framing could influence support for Clinton vs Trump, but whether these techniques would have worked in recent elections in the UK has not been empirically tested. This work seeks to test whether framing based on Moral Foundation Theory or using different dimensions of Personality (Openness and Conscientiousness), can influence how persuasive people find arguments for and against the UK’s membership of the EU.
University of Leicester
Psychological and Social Motivations in Microfinance Contracts: Theory and Evidence
Recent evidence on microfinance repayment rates suggests no difference between individual and joint liability contracts. However, the literature does not separate the role of public repayment from contractual incentives. We propose a theoretical framework that captures borrowers' psychological motivations such as guilt-aversion, reciprocity, and shame-aversion to capture behavioural factors for diligence under private and public repayments. We untangle these factors through lab-in-the-field experiments in Pakistan. In our 2x2 experimental design, we vary not just the liability structure of the loan contract, but also the public and private nature of repayment. We find large revealing treatment effects. Specifically, in private repayment, allocation to joint liability increases effort by almost 100% relative to an individual liability treatment. We find a strong causal effect of partner's expectation on borrowers' effort, confirming the guilt-aversion mechanism. In contrast, the same contractual comparison in public repayment reveals no difference in effort, implying the prevailing impact of shame-aversion due to the public nature of the payment. A comparison of individual liability in public and private repayment shows that effort increases by 60% in public treatment, confirming our shame-aversion hypothesis and the effectiveness of public repayment. The contrast of joint liability in private and public treatments accentuates the channel through which normative expectations influence effort decisions. Finally, we also find that reciprocity influences effort decisions of borrowers.