UCL Psychology and Language Sciences


London Judgement and Decision Making seminars

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:

- Lara Kirfel (lara-christina.kirfel.15@ucl.ac.uk),
- Sabine Topf (sabine.topf.14@ucl.ac.uk), and
- Tamara Shengelia (tamara.shengelia.15@ucl.ac.uk)

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 3 Seminar Schedule

May – June 2018


2nd May 2018

Going to extremes: How memories for big wins drive risky choice

Elliot Ludvig

University of Warwick

When people make risky choices based on past experience, they must rely on their memories of the odds and outcomes. Oftentimes, the choices that people make in those experience-based situations are different than the choices they make when those same odds and outcomes are explicitly described. Here, in a series of experiments, we show how people overweight the most extreme outcomes (biggest wins and losses) in memory, leading to increased gambling in some situations. The bias towards remembering big wins is context-dependent, counteracts somewhat the tendency to ignore rare events in experience, and can be enhanced through reminders. In addition, this focus on the big wins leads people to selectively gather information about potentially winning options. I interpret these results through the lens of a reinforcement-learning model, which learns from samples of past experience.


9th May 2018

Understanding the Ecosystem of Online Hate

Gianluca Stringhini


Over the last year harmful activity such as online harassment, hate speech, and misinformation have become an serious problem for online social networks. In particular, anecdotal evidence shows that polarized online communities (e.g., 4chan) play a key role in organizing hate campaigns against online users as well as generating conspiracy theories that are later pushed to mainstream outlets through coordinated efforts. In this talk, I will present our measurement studies geared towards characterizing these communities and measuring their impact on mainstream social networks. Our models allow us to better understand the ecosystem of online hate and misinformation.


16th May 2018

Call to Claim your Prize: Perceived Benefits and Risk Drive Intention to Comply in a Mass Marketing Scam

Yaniv Hanoch

University of Plymouth

Mass marketing scams (MMS) represents one of the most rapid growing crimes. It extracts an enormous financial and emotional toll, yet, there is a real dearth of empirical studies examining factors that could help explain response to scams. As MMS employ a range of tactics to entice potential victims, in a series of studies, we included a wide range of measures—age, education, numeracy, loneliness, and perception of benefits and risks—that could help us better understand why some people respond to scams while other refrains.  We also studied whether activation fee and cold vs. hot scam solicitations impact response rate. Our studies indicate that consumers are responding to perceived risks and benefits in their decision-making, regardless of persuasion elements used by scammers. Furthermore, our studies indicate that consumers with lower levels of education and high perception of benefits are at increased risk for mass marketing scams.

23rd May 2018

The psychology of group processes and behavioural decision theory meet decision analysis in modelling the harms from the mis-use of psychoactive drugs

Larry Phillips & David Nutt

LSE/Imperial College London

Behind the Lancet 2010 paper, Drug harms in the UK: a multicriteria decision analysis, lies a curious mixture of disciplines that enabled us to obtain judgements of physical, psychological, and social harms to users and others from a very diverse group of experts. Impartial facilitation with an understanding of group processes and of potential biases in judgements, provided a setting that enabled the group to provide reliable and valid assessments of the harms of 20 drugs on 16 criteria. Professor Nutt will explain the problem and its personal, social, and political context, while Professor Phillips will explain the methodology that enables the aggregation of coherent assessments.


30th May 2018

The Hot Hand Fallacy Fallacy

Joshua Miller

University of Alicante

The hot hand fallacy has long been considered a massive and widespread cognitive illusion with important implications for decision making.  We uncover a subtle, but critical, statistical bias that invalidates previous evidence supporting the hot hand fallacy in its canonical domain, basketball shooting. We re-assess and re-analyze basketball shooting and betting data. We find that the hot hand exists, and that players can bet on it successfully.

6th June 2018

Maintaining Credibility When Communicating Risk and Uncertainty: The Role of Communication Format

Sarah Jenkins


Uncertainty is a common hallmark of science, yet it is often perceived by the public as an ‘indicator of ignorance’, which presents a challenge for communicators. Whilst much research has focused on how individuals understand risk and uncertainty information, relatively little has examined how the communicator of the information is perceived. However, the latter is a key part of the risk communication process – a communication will likely be ignored and dismissed if the communicator is not perceived as trustworthy or knowledgeable. In this talk, I present research which investigates how people understand and perceive three types of communication formats: verbal probability expressions (VPEs) (e.g. ‘unlikely’); numerical expressions (e.g. ‘20%’) and mixed expressions (e.g. ‘unlikely [20%]’). The results indicate that misunderstandings of uncertainty can negatively influence perceptions of a communicator’s credibility, though the extent to which this occurs varies according to communication format. Our findings suggest numbers should be used in consequential risk communications regarding ‘unlikely’ events, wherever possible.