UCL Psychology and Language Sciences


London Judgment and Decision Making seminars

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.

Unless specified otherwise, all seminars take place on Wednesdays from 5:15-6:15 PM UK time. The seminar series in 2023/24 will be held in a hybrid format via Zoom as well as at University College London. 

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.

Titles, abstracts and recordings (where available) of previous seminars can be found here. 

The LJDM seminar series is supported by

University College London
City, University of London
Kings College London

If you would like to present your research to the group or to suggest a speaker, please contact the organizers:

Academic Year 2023/24

Wednesday 4th October 2023

Talk cancelled due to TFL strikes.


Wednesday 11th October 2023

Dr David Hagmann (The Hong Kong University of Science and Technology)

Agent Selection and Belief Polarization in Distributive Bargaining

Principals frequently bargain through agents, and field evidence suggests that such bargaining often ends in costly impasse. While a large literature has examined the potential misalignment of interests between principals and agents, the process that precedes such relationships has been neglected: the principal's selection of an agent. In this paper, we examine _agent-selection_ in bargaining and show that principals tend to select overly aggressive agents to their own detriment. Across three preregistered experiments (combined n = 3,190), we find that selected agents sent to the bargaining table are not only more polarized in their views than are agents in general (Study 1), but they are also more polarized than the principals whom they represent (Study 2). As a result, principals fare worse than if they were assigned an agent at random or negotiated on their own behalf. Conditional on engaging in agent-selection, both parties could improve their respective outcome by unilaterally selecting a less aggressive agent. In an extension with repeated selection and information asymmetry, we show that these less-aggressive agents fail to persist in the market. Principals neglect the increasing polarization of the agent pool, continue to select relatively aggressive agents, and become more polarized in their own beliefs (Study 3).

The seminar will take place in person, in room 305, Bedford Way.

For online attendance, join via Zoom.


Wednesday 18th October 2023

Dr Alice Mason (University of Bath)

Understanding the uncertainty inherent in climate projections is crucial for robust future planning and decision-making.   
Recent calls have urged the scientific community to face the challenge of improving communication about worst-case scenarios for climate change. Such scenarios are informed by climate projections which are often presented as a numerical range - for example, by 2100 global surface temperatures will increase by between 4 and 7.2 degrees. In a series of behavioural experiments, we show that people interpret identical projected future temperature ranges (e.g., 4℃ to 7.2℃ by 2100), differently as a function of their optimism or pessimism about the path that future emissions will take (current, best or worst-case). The presence of these biases raises important implications for the communication of climate futures."

The seminar will take place in person, in room 305, Bedford Way.

For online attendance, join via Zoom.


Wednesday 25th October 2023

Prof Lasana Harris (UCL)

The Impact of Dorsolateral Prefrontal Cortex on Deviations from Moral Defaults

Decades of cognitive neuroscience research establishes the role of the dorsolateral prefrontal cortex (DLPFC) in a cognitive control brain network. Here, I explore its function during moral decisions where people must override their moral defaults—behaviour consistent with moral impulses or normative behaviour. In a ticking time-bomb paradigm, we find causal evidence for DLPFC involvement in deviations from a moral prior when searching for optimal administration of hypothetical torture techniques. In a consensus dice roll paradigm, we find causal evidence for DLPFC involvement in deviations from group norms that promote or avoid collusion to defraud the experiment. These data suggests that cognitive control interacts with social cognition mechanisms during moral decision-making, facilitating moral adherence or deviance.

The seminar will take place in person, in room 305, Bedford Way.

For online attendance, join via Zoom.


Wednesday 1st November 2023

Dr Mikhail Spektor (University of Warwick)

What is “context" and how to test for its effects

What is "context", and how can we best test for its influence (or the lack thereof)? The diversity in settings covered by the literature on contextual influences, spanning from low-level foraging tasks in amoeboid organisms to real-world market behaviour, goes hand-in-hand with an almost equal diversity of testing approaches designed to assess the presence of context effects. Are all these studies testing the same concept of "context"? How do the design decisions relate to the theoretical framework that is being subjected to the test? The present project aims to clarify these questions and provide guidelines on which experimental designs are most suitable for testing specific theoretical properties.

The seminar will take place in person, in room 305, Bedford Way.

For online attendance, join via Zoom.


Reading Week


Wednesday 15th November 2023

Dr Tia Gong (University of Edinburgh)

How do we find causal structure in time?

Time is integral to our understanding of the world, shaping how we link the things that happen around us and the actions we take. Despite decades of development of causal learning theory, no one has comprehensively addressed the role of time in structure learning. In this talk, I will describe recent studies investigating how people use time information to make causal inferences. I start with an empirical study showing the unique continuous feature of temporal information in inference. I then propose a rational framework for causal induction based on continuous-time evidence, examine human performance in both passive and active causal learning tasks, and develop several boundedly rational process accounts that help explain human judgments and intervention strategies.

The seminar will take place in person, in room 305, Bedford Way.

For online attendance, join via Zoom.


Wednesday 22nd November 2023

Prof Teneille Brown (University of Utah)

Minding Accidents

Tort doctrine in the U.S., U.K. and Australia states that breach is all about conduct. Unlike in the criminal law, where jurors must engage in an amateur form of mindreading to evaluate mens rea, jurors are told that they can assess civil negligence by looking only at how the defendant behaved. But this is probably false. Foreseeability is at the heart of negligence—appearing as the primary test for the key elements of duty, breach, and proximate cause. And yet, we cannot ask whether a defendant should have foreseen a risk without interrogating what he subjectively knew, remembered, perceived, or realized at the time. In this talk I will use findings from a mock jury study I ran with social psychologist Francesco Margoni to question whether jurors in fact use mental states to assess negligence.  

The seminar will take place in person, in room 305, Bedford Way.

For online attendance, join via Zoom.


Wednesday 29th November 2023

Dr Frederike Beyer (Queen Mary University of London)

Rewarding actions: impact of motor behaviour on the processing of reward and punishment

Associative learning underpins many models of human behaviour, from theories of social behaviour to models of addiction. The two types of associative learning – pavlovian conditioning and instrumental learning – are generally understood as independent processes, but recent work suggests close links between the two. Studies in both humans and non-human animals suggest existing pavlovian associations can bias instrumental behaviour. Here, in a series of studies, we ask whether the opposite is true as well: can performing a motor action affect pavlovian learning? In a novel task, we manipulated on a trial-wise basis whether participants performed an action or not, and whether they received rewarding or punishing feedback. Crucially, the performance of a motor action was uncoupled from instrumental control. Using EEG, we showed that the processing of both monetary and social rewards is enhanced by performing a button press, suggesting close interactions between neural systems controlling motor behaviour, and those processing reward. We further found modulation of the neural response to probabilistic cues by both the valence of the predicted outcome and performing a motor action. In a behavioural pilot study, we found evidence for the formation of stimulus preferences, which was not modulated by motor action. Together, these findings have important implications for our understanding of behavioural addictions such as gambling, as well as for our understanding of associative learning in general. Future work needs a more in-depth exploration of behavioural effects and the formation of incentive salience.

The seminar will take place in person, in room 305, Bedford Way.

For online attendance, join via Zoom.


Wednesday 6th December 2023

Dr Jonas Schoene  (Stanford University)

Using LLMs to Build and Crowdsource the Next Generation of Well-Being Interventions

Traditional well-being interventions typically involve one-time, pen-and-paper or online surveys. While these have proven effective, they heavily rely on participants' abilities to follow instructions and have experienced high dropout rates, particularly among those with poorer well-being. To address this, we augment these interventions by incorporating Large Language Models (LLMs). In this talk, I will first present insights from our initial pilots, where we compare a conventional gratitude letter exercise with an AI-enhanced version. The overarching goal of this project is to demonstrate that AI chatbots can facilitate task completion while maximizing well-being benefits, demonstrating a more feasible and effective alternative to traditional methods in improving well-being. As part of this project, we will invite a diverse group of people to share their intervention ideas to identify the most effective interventions through a large AI-chatbot competition hosted by our lab.

For online attendance, join via Zoom.


Wednesday 13th December 2023

Dr Abdullah M. Almaatouq (MIT)

Beyond Playing 20 Questions with Nature

The social and behavioral sciences often struggle to integrate experimental findings. This is, at least in part, due to what Newell called "playing twenty questions with nature" paradigm, which focuses on testing individual theory predictions one-at-a-time and assumes that integration of findings happens via the scientific publishing process. However, I'll argue that this integration process is either inefficient or, in many cases, doesn't actually happen. Addressing this challenge goes beyond just improving the reliability and replicability of individual experiments or conducting larger ones; it calls for a fundamental rethink of experimental design and its ties to theory. In this talk, I will present the "integrative experiment design" framework, which promotes commensurability and continuous knowledge integration by design, which (hopefully?) would lead to more reliable, cumulative empirical and theoretical progress.

For online attendance, join via Zoom.


Christmas Break


Wednesday 10th January 2024

Prof David Lagnado (UCL)

Is the witness lying? Modelling deception using Bayes nets

Deception is a common threat in domains such as law, politics, and everyday life. While there is plenty of research on people’s ability to detect deception, much less work exists on how people update their beliefs given potentially deceptive testimony. We present a Bayesian network model for handling deception and highlight some counterintuitive implications of this model. In two studies we show that participants depart from the Bayesian model. We argue that people use simplifying assumptions that are intuitively appealing but can lead to error.

The seminar will take place in person, in room 305, 26 Bedford Way.

For online attendance, join via Zoom.


Wednesday 17th January 2024

Benno Guenther (LSE/UCT)

The Disposition Effect in Investing: Understanding, Overcoming and Embracing Behavioural Biases

This talk explores nuances of the disposition effect, a critical behavioural bias in investment decisions where investors realise winning investments while holding on to losing ones, often resulting in suboptimal financial outcomes. Drawing from two research studies — one involving real retail investors and the other professional investors, the talk will provide an examination of this phenomenon and the efficacy of interventions designed to mitigate it.

The first part of the talk will introduce the disposition effect, discussing
its implications for retail and other investors. We'll explore the psychological mechanisms behind why investors fall prey to this bias and the resulting impact on investment returns. In the second part, we will discuss the findings from the two studies in detail. The first study, conducted with retail investors, used an informational feedback intervention to mitigate the disposition effect. The second study, involving professional traders, offers a contrasting perspective on the bias. We will highlight the nuanced understanding that the disposition effect is not uniformly detrimental; its impact can vary depending on market conditions. This part of the talk will critically examine how market dynamics can influence the effectiveness of the disposition effect on investment strategies.

The talk aims to provide a nuanced understanding of the disposition effect, emphasizing that its influence is not black and white and can differ based on the type of investor and market conditions. Attendees will gain insights into how different interventions can be tailored and how to navigate the disposition effect to make more informed investment decisions.

The seminar will take place in person, in room 305, 26 Bedford Way.

For online attendance, join via Zoom.


Wednesday 24th January 2024

Renos Vakis (World Bank)

Changing Student Attitudes at Scale Through Theories of Intelligence

This lecture will showcase some of the work the Mind, Behavior, Development Unit at the World Bank is doing in development policy around the world and go deeper into recent school-based psychosocial interventions to improve student outcomes around the world. Overall, the lessons to-date suggest that interventions that focus on shifting students towards positive mental models can be cost-effective to improve long term school performance.

The seminar will take place in person, in room 305, 26 Bedford Way.

For online attendance, join via Zoom.


Wednesday 31st January 2024

Dr Christian Krekel (LSE)

Back to Edgeworth? Estimating the Value of Time Using Hedonic Experiences

Following early economist Francis Y. Edgeworth's proposal to measure people's hedonic experiences as they go about their daily lives, we use a smartphone app that over eight years randomly asked a panel of 30,936 UK residents (N=2,235,733) about their momentary feelings and activities to estimate the value of time (VOT), a key input into cost-benefit analyses. Exploiting the randomised timing of surveys for identification, we arrive at a VOT of GBP 12.2 (USD 15.3) per hour of waiting, GBP 8.4 (USD 10.5) per hour of commuting, and GBP 17.2 (USD 21.5) per hour of waiting during commuting (e.g. due to congestion). This resembles estimates from studies using revealed preferences, suggesting that using hedonic experiences leads to similar results as observed behaviour. Our unique data and method also allow us to estimate the VOT for 40 other daily activities as well as their interactions. We are the first to value time (or indeed anything) using hedonic experiences in real-time, which has the potential to value other intangibles too.

The seminar will take place in person, in room 305, 26 Bedford Way.

For online attendance, join via Zoom.


Wednesday 7th February 2024

Dr Lee Curley (The Open University)

Informing Reform: An empirical investigation into the utility of the not proven verdict

Scotland, unlike other legal jurisdictions, currently has three verdicts available to jurors: Guilty; Not guilty; and, Not Proven. The Not Proven verdict is an acquittal verdict unique to Scotland, which has the same legal implications as a Not Guilty verdict. Due to scepticism surrounding the legitimacy of the not proven verdict, the Scottish government are hoping to reform the current verdict system based on research and public consultation. Our research, through a series of experiments, has investigated the decision making of jurors in the current system (Guilty, Not Guilty and Not Proven), the system used in England and Wales (Guilty and Not guilty), and other experimental systems (e.g., Proven and Not Proven) to investigate the effects of verdict number (two versus three) and the word choice of the verdict (guilt versus proven) on conviction and acquittal rates. Further, we have also discussed the potential impact of reform with key legal stakeholders, such as prosecution and defence lawyers and judges. This talk will introduce you to the history behind the Scottish verdict system, the political context surrounding legal reform in Scotland, and the psychological impact of varying verdict systems on jurors.

The seminar will take place online, with the option to join a watch group in room 305, 26 Bedford Way.

For online attendance, join via Zoom.


Reading Week


Wednesday 21st February 2024

Dr Nadia Morozova (Warwick Business School - The University of Warwick)

The Urge to Splurge: Differentiating Unplanned and Impulse Purchases

This research addresses a significant gap in the literature regarding the underlying mechanisms of purchase decision-making that lead to unplanned and impulse purchases. The study shows that there exist significant differences among planned, unplanned and impulse purchases in terms of shoppers’ emotional engagement and cognitive involvement in the decision-making process. Moreover, these three types of purchases can be distinguished by different shoppers’ path to purchase and in-store triggers used for decision-making.

In order to achieve an in-depth understanding of the nature of planned, unplanned and impulse purchases and underlying mechanisms of the purchase decision-making process, we blended various research methodologies. Thus, to identify shoppers’ emotional engagement and cognitive involvement in their decision-making, we combined physiological data from E4 wristbands and mouse tracking data collected in the course of a shopping trip. To determine a type of purchase, we conducted a systematic literature review, and developed and tested a scale based on its results.

This research enabled us to provide academic recommendations, including definitions of planned, unplanned and impulse purchases. Moreover, business recommendations were developed, which can be applied by e-tailers, consumer brands and Social Media companies.

The seminar will take place in person, in room 305, 26 Bedford Way.

For online attendance, join via Zoom.


Wednesday 28th February 2024

Dr Julia Nolte (Tilburg University)

Much Ado about "No Thanks"?  Adult Age Differences in Avoidance Tendencies

More than three decades of research have established that older adults tend to search for fewer pieces of information when making decisions, for example about consumer goods or their health. This puts older adults at risk of making ill-informed decisions or experiencing poorer decision outcomes. In this talk, I summarize recent research showing that older adults not only passively underuse information but also actively avoid decision-relevant information in some contexts (e.g., Deng et al., 2022; Nolte et al., 2021; Mei et al., in prep.). This tendency mirrors age-related preferences for avoiding decision making altogether, for example by delaying or outsourcing choice. Because the underlying reasons remain poorly understood, I will discuss known and suspected correlates of older adults' heightened avoidance tendencies (e.g., Nolte & Löckenhoff, 2022; Nolte & Löckenhoff, in prep.). Finally, I will highlight potential avenues for encouraging informed decision making among older adults, for example by matching information to different age groups' information processing preferences (Nolte et al., 2022).

The talk will be online

For online attendance, join via Zoom



Wednesday 6th March 2024

Prof Robert West (Professor Emeritus of Health Psychology, UCL)

Characterising diversity in ‘real-world’ decision making 

This presentation will present for discussion a first draft of a framework to characterise the diversity of ‘real-world’ decision making. It classifies the diversity under the four main processes involved: Framing, Assessing, Comparing, and Enacting (FACE). The framework will form part of a forthcoming book on decision making, ‘Reflect: The Science of Real-World Decision making’.

Human behaviour often involves people stopping, however briefly, and actively thinking about what to do. This process of decision-making can go beyond just thinking to activities such as seeking out information and using decision aids.

There is huge diversity in the way that decision making is undertaken in the ‘real world’.

The seminar will take place in person, in room 305, 26 Bedford Way.

For online attendance, join via Zoom.



Wednesday 13th March 2024

NO LJDM talk this week



Wednesday 20th March 2024

Dr Eleni Mantzari (University of Cambridge)

Size matters: the impact of the size of glasses, bottles and servings on alcohol consumption.

Alcohol consumption contributes to the development of many diseases, including seven cancers. People consume more food and non-alcoholic drinks when presented with larger portions or packages and when using larger items of tableware. Although this well documented “portion size effect” for food has, until recently, been neglected as a focus of study for alcohol consumption, it suggests that reducing the servings and containers for alcohol could contribute towards reducing consumption across populations. In a series of field studies, we test this hypothesis by assessing the impact of changing two dimensions of size relevant to the consumption of alcohol: the container size of an alcoholic drink, encompassing both drinking vessels -i.e., glasses - and pouring vessels -i.e., bottles - and the serving size of an alcoholic drink.


Wednesday 1st May 2024

Dr Rebecca Neel (University of Toronto)

The stigma of perceived irrelevance

When and why are stigmatized group members overlooked, ignored, and treated with indifference – that is, “invisible”? How can we predict when this form of stigmatization will occur, rather than negative prejudice and active discrimination? I present theory and evidence arguing that invisibility emerges from perceived goal-irrelevance. This approach suggests that rather than only particular target groups being invisible, invisibility dynamically changes across perceiver goals, target cues, and situational features. Nonetheless, some perceivers, targets, and situations are especially likely to lead to invisibility. I will present findings from both target and perceiver perspectives exploring the dynamic nature of invisibility.

The talk will be online

For online attendance, join via Zoom


Wednesday 8th May 2024

Dr Moshe Glickman (University College London)

How human-AI feedback loops alter human perceptual, emotional and social judgments

Artificial intelligence (AI) technologies are rapidly advancing, enhancing human capabilities across various fields spanning from finance to medicine. Despite their numerous advantages, AI systems can exhibit biases in judgments in domains ranging from perception to emotion. Here, in a series of experiments (= 1,401), we reveal a feedback loop where human-AI interactions alter processes underlying human perceptual, emotional and social judgements, subsequently amplifying biases in humans. This amplification is significantly greater than observed in interactions between humans, due both to the tendency of AI systems to amplify biases and to how humans perceive AI systems. Participants are often unaware of the extent of the AI’s influence, rendering them more susceptible to it. These findings uncover a mechanism wherein AI systems amplify human biases, which are further internalized by humans during human-AI interactions, triggering a snowball effect where small errors in judgment escalate into much larger ones.

The seminar will take place in person, in room 675, 20 Bedford Way.

For online attendance, join via Zoom.


Wednesday 15th May 2024

Talk Postponed - NO LJDM talk this week



Wednesday 22nd May 2024

 Prof Don Moore (University of California, Berkeley)

Thinking and Confidence

People often make simplifying assumptions in order to understand complex systems. This fact can explain the ubiquity of overprecision: the tendency for people to be too certain they are right. The reason is that using simplified models that ignore some variation-inducing complexity causes judgments to be overprecise. We introduce a simple model of overprecision and then provide empirical evidence, both from the experimental laboratory and from the field, that tests the predictions of that theory.

The seminar will take place in person, in room 636, 20 Bedford Way.

For online attendance, join via Zoom.