UCL Psychology and Language Sciences


London Judgement 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 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.

The LJDM seminar series is supported by

University College London
City, University of London

If you would like to present your research to the group or to suggest a speaker, please contact the organizers:
- Tamara Shengelia (tamara.shengelia.15@ucl.ac.uk)
- Sabine Topf (sabine.topf.14@ucl.ac.uk)
- Ayse Ozsari-Sahin (ayse.sahin.18@ucl.ac.uk)

Seminar Schedule Term 3

May – June 2020


Please note that this term all seminars will be held online. To receive the link for joining the respective seminars, please subscribe to the mailing list or check back here on this site on the day.


6 May 2020 | Christian List | LSE | Join this seminar here

The naturalistic case for free will

Free-will scepticism is becoming increasingly influential. A number of popular science writers and some scientists in fields ranging from physics to neuroscience have prominently argued that the notion of free will – a person’s capacity to choose and control his or her own actions – has no place in modern science. Human actions, they say, are caused not by people’s conscious mental states, but by physical processes in their brains and bodies and the world at large, processes over which people have no control. If this is right, the idea of free will is a remnant of a superseded, unscientific worldview. The aim of this talk is to argue against this growing scepticism. My thesis is that, far from being undermined by a scientific worldview, the idea of free will is actually supported by the sciences of human behaviour. Free will, carefully defined, is a three-part capacity: the capacity of intentional agency, choice between alternative possibilities, and causal control over the resulting actions. This capacity, I suggest, is presupposed by some of our best explanatory theories of human decision-making, including decision and game theory in economics and the social sciences. Insofar as we have good grounds to adopt a realist interpretation of our best scientific theories, there is a good naturalistic case for free will. An informal background paper is available at: https://philpapers.org/archive/CARFWR.pdf


13 May 2020 | Rebecca McDonald / Johannes Lohse | University of Birmingham | Join this seminar here

Avoiding out-group information: information acquisition and group identity

How do people choose to get informed? A relevant consideration is the source of information. Echo-chambers and in-group favouritism have been well documented, but to date the separate roles of in-group favouritism and out-group disfavouritism have not been explored. In our laboratory sender-receiver game, receivers had to guess the true state of the world. To help them, they could purchase information from informed senders. However, these senders were incentivised to lie. Specifically, senders were incentivised to report a given state of the world (irrespective of the truth), and the strength of this lying incentive was varied across trials. Knowing senders’ incentives to lie, receivers could choose to receive information from neither, one, or both of two senders. We induced group identity using the Chen and Li (2009) paradigm to explore how people trade off the likely quality of the signal, versus the group identity of its sender. Our results suggest only minimal preference for in-group news. Instead, we observed active avoidance of information from out-group senders, even when it is likely to be informative. We recently followed up with an online experiment that investigated how home-grown group identity influences receivers’ information preferences.

20 May 2020 | Peter Ayton & Leonardo Weiss-Cohen | City, University of London & Leeds University Business School | Join this seminar here

Smoking versus vaping: How (not) to communicate their relative harms

Here we consider how the relative harms of two nicotine products were communicated in a public health campaign.  Following a peer-reviewed evaluation that rated the relative harm of a range of nicotine products relative to the harm of smoking, and which rated the relative harm of vaping as about 5% that of smoking (D. J. Nutt et al., 2014 European Addiction Research, 20(5), 218–225), the UK government launched a campaign which transposed these relative harms into relative safety, promoting the message that “vaping is 95% safer than smoking”.  We discuss the communication issues arising from transposing a measure of relative harms into relative safety and report the results of an experiment which shows that significantly more people correctly appreciated the ratio of the relative harms from smoking and vaping after reading the statement “vaping is 5% as harmful as smoking” than after reading the statement “vaping is 95% safer than smoking”. We discuss the policy implications of our findings. 


27 May 2020 | Ro'i Zultan | Ben-Gurion University of the Negev | Join this seminar here

Postponed to 10th June (please see below for details)


3 June 2020 | Jo Cutler | University of Oxford | Join this seminar here

When and why do we value outcomes for others? Insights from brain, body and behaviour

Prosocial behaviours, actions that benefit others, lead to a huge number of positive outcomes for recipients, society, and even the person being altruistic. Many possible motivations for altruistic decisions have been identified, only some of which depend on valuing the wellbeing of others. In this talk, I will present data from neuroimaging, physiological recordings, and behavioural studies that suggest people do value and are interested in outcomes affecting strangers. However, I will also show that prosocial motivations depend on individual differences, including changes across the lifespan, and situational factors, which create biases in who is valued.


10 June 2020 | Ro'i Zultan | Ben-Gurion University of the Negev | Join this seminar here

The Moral Comparison of Modes of Deception: A New Experimental Approach for Solving an Old Normative Debate

Deception is the intentional causation of false beliefs in the other. One of the central questions debated in the ethics of deception involves the moral ranking of different types of deception based on the form of communication. We identify two major normative positions in this debate. The Classical View (CV) is that lying is morally worse than the other modes of deception. The Equivalence Thesis (ET) states that, as long as the intent and the consequences are the same, it makes no difference morally how one deceives.

We argue that empirical data on behavior in the different modes of deception is relevant to the normative discussion. We therefore test this question using an experimental investment game involving one consultant and one investor. In different conditions, the consultant has the opportunity to deceive the investor by either lying, falsely implicating (telling a misleading truth), or through nonlinguistic deception. In two studies, we find no significant differences between the three experimental conditions, neither among consultants nor among investors. While equivalence in behavior does not logically imply normative equivalence, we show that the empirical results can support four different normative arguments in support of the ET.