Peter Ayton

University of Leeds

For over 30 years, prevalence surveys have been the principal methodology for measuring the distribution of gambling-related harm in a population (Volberg, 2004), and have informed debates around whether existing harm reduction efforts are working, both in the academic literature (Shaffer et al., 2004) and in the news (Davies, 2022). Despite this l...

In many places commemorative plaques are erected on buildings to serve as historical markers of notable men and women who lived in them – London has a Blue Plaque scheme for this purpose. We investigated the influence of commemorative Blue Plaques on the selling prices of London real estate. We identified properties which sold both before and after...

Previous research has demonstrated a ‘seductive allure’ of technical or reductive language such that bad (e.g., circular) explanations are judged better when irrelevant technical terms are included. We aimed to explore if such an effect was observable in relation to a covid-19 vaccinations and if this subsequently affected behavioural intentions to...

Objective: To investigate whether performance (number of correct decisions) of humans supported by a computer alerting tool can be improved by tailoring the tool's alerting threshold (sensitivity/specificity combination) according to user ability and task difficulty. Background: Many researchers implicitly assume that for each tool there exists a s...

When deciding where to invest, individuals choose mutual funds based on recent past performance, despite standard mandated disclaimers that "past performance does not guarantee future results." Investors would receive better long-term returns by choosing funds with lower fees. We explored the impact of fees and past performance on realistic mutual...

Pension trustees make surrogate decisions on behalf of scheme members. However, prior research has not explored how this might affect pension adequacy. Our results show that when setting targets for pension replacement income, trustees project their own preferences instead of reflecting member preferences. Furthermore, projection was more pronounce...

When deciding where to invest, individuals choose mutual funds based on recent past performance, despite standard mandated disclaimers that "past performance does not guarantee future results." Investors would receive better long-term returns by choosing funds with lower fees. We explored the impact of fees and past performance on realistic mutual...

The COVID-19 pandemic constitutes a novel threat and traditional and new media provide people with an abundance of information and misinformation on the topic. In the current study, we investigated who tends to trust what type of mis/information. The data were collected in Norway from a sample of 405 participants during the first wave of COVID-19 i...

Background: Previous research has demonstrated a ‘seductive allure’ of technical or reductive language. Specifically, bad explanations – i.e., those presenting circular restatements of a phenomenon or other non-explanatory information – are judged better explanations when irrelevant technical language is included.Methods: Using a between subjects d...

The attempts to mitigate the unprecedented health, economic, and social disruptions caused by the COVID-19 pandemic are largely dependent on establishing compliance to behavioral guidelines and rules that reduce the risk of infection. Here, by conducting an online survey that tested participants’ knowledge about the disease and measured demographic...

Background: By the end of March 2020, more than a fifth of the world's population was in various degrees of "lockdown" in order to slow the spread of COVID-19. This enforced confinement led some to liken lockdown to imprisonment. We directly compared individual's experiences of lockdown with prisoners' experiences of imprisonment in order to deter...

Background: By the end of March 2020, more than a fifth of the world’s population was in various degrees of ‘lockdown’ in order to slow the spread of Covid-19. This enforced confinement led some to liken lockdown to imprisonment. We directly compared individual’s experiences of lockdown with prisoners’ experiences of imprisonment in order to determ...

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 Nutt, D. J...

Pension scheme trustees are responsible for the investment decisions of future generations’ retirement assets. However, behavioural finance research has mostly focussed on retail investors. While trustees are relatively sophisticated investors, they are not immune from biases. Across three experiments, we tested 252 pension scheme trustees for the...

Purpose Behavioral finance research has almost exclusively investigated the decision making of lay individuals, mostly ignoring more sophisticated institutional investors. The purpose of this paper is to better understand the relatively unexplored field of investment decisions made by pension fund trustees, an important subset of institutional inv...

Following the airplane attacks of September 11th, 2001 it is claimed that many Americans, dreading a repeat of these events, drove instead of flying, and that, consequently, there were extra car accidents, increasing the number of fatalities directly caused by the attacks by 1,500. After the Madrid train bombings of March 11th, 2004, Spaniards, lik...

Financial risky decisions and evaluations pervade many human everyday activities. Scientific research in such decision-making typically explores the influence of socio-economic and cognitive factors on financial behavior. However, very little research has explored the holistic influence of contextual, emotional, and hormonal factors on preferences...

Retrospective evaluation (RE) of event sequences are known to be biased in various ways. The present paper presents a series of studies that examined the suggestion that the moments that are the most accessible in memory at the point of RE contribute to these biases. As predicted by this memory-based analysis, Experiment 1 showed that pleasantness...

Karlsson, Loewenstein and Seppi (2009) found that, following market downswings, investors are less likely to login to monitor their retirement portfolios. They concluded that, rather like (apocryphal) ostriches sticking their heads in the sand, investors avoid unpleasant information by reducing portfolio monitoring in response to news of negative m...

Introduction Doctors constantly make decisions that affect the health and lives of other people. They gather evidence by interpreting the signs and symptoms of the patient, conducting examinations and determining appropriate tests. All of these actions imply the use of judgement and decision-making. Using such evidence they may form a diagnosis and...

Computer aids can affect decisions in complex ways, potentially even making them worse; common assessment methods may miss these effects. We developed a method for estimating the quality of decisions, as well as how computer aids affect it, and applied it to computer-aided detection (CAD) of cancer, reanalyzing data from a published study where 50...

This paper explores whether and how feedback, framing, personality, and risk attitude could affect financial optimism in an enclosed experimental environment. Evidence in this paper shows that feedback on investment performance affects financial optimism depending on whether people forecast returns in absolute values or in relative terms. Financial...

This study investigates whether being financially optimistic has any benefits on objective and subjective well-being. We define financial optimism as the likelihood of a positive outcome relative to rational expectation in an individual’s future financial situation. We analyze data from the British Household Panel Survey from 1991. We found that op...

Six experiments studied relative frequency judgment and recall of sequentially presented items drawn from 2 distinct categories (i.e., city and animal). The experiments show that judged frequencies of categories of sequentially encountered stimuli are affected by certain properties of the sequence configuration. We found (a) a first-run effect wher...

We compared Turkish and English students' soccer forecasting for English soccer matches. Although the Turkish students knew very little about English soccer, they selected teams on the basis of familiarity with the team (or its identified city); their prediction success was surprisingly similar to knowledgeable English students---consistent with Go...

This study investigates whether being financially optimistic has any benefits on objective and subjective well-being. We define financial optimism as the overestimation of the favorable outcome in an individual's future financial situation. We analyze data from the British Household Panel Survey covering the period 1991 to 2007. We find that financ...

Our aim was to determine whether anaesthetists routinely confirm their ability to ventilate a patient's lungs by a facemask before the administration of a neuromuscular blocker and the rationale for this practice. An online survey of trainee and non-trainee anaesthetists working in hospitals forming part of the Central London School of Anaesthesia...

This study develops innovative measures of financial optimism by defining optimism as the overestimation of the favourable outcome in an individual’s future financial situation. The paper finds that optimism has a positive influence on an individual’s preference for risky portfolios and a negative impact on her preference for risk-free portfolios w...

A proposed remedy for biased affective forecasts is to base judgments on the actual feelings of people (surrogates) currently experiencing the event, rather than using imagination which conjures an inaccurate vision of the future. Gilbert et al. (2009) forced people to use surrogate reports by withholding all event information, resulting in better...

In 5 experiments, we studied precautionary decisions in which participants decided whether or not to buy insurance with specified cost against an undesirable event with specified probability and cost. We compared the risks taken for precautionary decisions with those taken for equivalent monetary gambles. Fitting these data to Tversky and Kahneman'...

In many applications of computerised decision support, a recognised source of undesired outcomes is operators' apparent over-reliance on automation. For instance, an operator may fail to react to a potentially dangerous situation because a computer fails to generate an alarm. However, the very use of terms like "over-reliance" betrays possible misu...

Any individual's response intended to be random should be as probable as any other. However, 3 experiments show that many people's independent responses depart from the expected chance distribution. Participants responding to instructions of chance and related concepts favor the available options unequally in a similar way. Consequently, in hide-an...

People overestimate the impact of health conditions on happiness, putatively because they focus excessively on resulting negative consequences while disregarding the impact of other unchanged aspects of life on happiness. However, typically, inferences about accuracy have been based on a confound of the viewpoint of judgments(Self/Other) with wheth...

This book presents accounts of economic and psychological analyses of association football (or "soccer" as it is popularly known in the USA). As football is widely accepted to be the world's most popular sport, the case for scientific investigation of its characteristics is self-evident. As the contributions to this book demonstrate, the game of fo...

Calculating risk is relatively straightforward when there is reliable statistical evidence on which to base a judgment. However, novel technologies are often characterised by a lack of such historical data, which creates a problem for risk assessment. In fact, numerical risk assessments can be positively misleading in such situations. We describe a...

This study investigates the effect of imminence, time duration and subjective desirability on judgemental forecasts. People were found to be more sure of specified events happening in a one-month time period subsequent to an imminent one-month period. The time duration of a forecast period, one month versus two months, had no effect on forecasting...

Object To understand decision processes in CAD-supported breast screening by analysing how prompts affect readers’ judgements of individual mammographic features (lesions). To this end we analysed hitherto unexamined details of reports completed by mammogram readers in an earlier evaluation of a CAD tool. Material and methods Assessments of lesions...

The study investigated the effects of time spent in prison and quality of life before prison on male, federally sentenced prisoners' adaptations to imprisonment, controlling for sentence length and prison security level. Data consisted of responses on a self-administered survey completed by 712 prisoners. Findings tended to support the independent...

Two studies explore the frequently reported finding that affective forecasts are too extreme. In the first study, driving test candidates forecast the emotional consequences of failing. Test failers overestimated the duration of their disappointment. Greater previous experience of this emotional event did not lead to any greater accuracy of the for...

A research group of four judgement and decision-making experts was convened to examine the literature on risky human behaviour, including driving, and to make recommendations on what format, structure and content is likely to have the biggest impact on road safety attitudes and behaviour in the specific group of convicted traffic offenders. The ove...

Prisoners' forecasts of post-release success may have implications for how they respond to imprisonment, release, and parole decisions. We examined sentenced US and UK prisoners' forecasts of recidivism, and how well UK prisoners believed they would fare compared to the average other prisoner. In both samples, forecasts of recidivism were unrealist...

We discuss the results of an interdisciplinary study of computer-aided decision making in cancer screening. We found evidence of "automation bias" - roughly, over-reliance on automation, which may degrade users' performance. While such effects are well known, they have not been previously reported for this application with expert clinicians, and ar...

Psychological research on Subjective Probability has used a variety of strategies to investigate how reliable people are at judging probabilities. The issue is of considerable practical importance as all sorts of critical decisions depend on assessment of the likelihood of events for which there is neither a method for mathematically computing its...

Summary form only given. Developments in computing offer experts in many fields specialised support for decision making under uncertainty. However, the impact of these technologies remains controversial. In particular, it is not clear how advice of variable quality from a computer may affect human decision makers. Here the author reviews research s...

A longitudinal study tested whether a regret-based intervention could persuade computer users to make more security-conscious choices in relation to backing up their work and internet security. Computing science students reported their attitudes and behaviour in relation to the two issues at three timepoints (baseline, intervention and follow-up ph...

We summarise a set of analyses and studies conducted to assess the effects of the use of a computer-aided detection (CAD) tool in breast screening. We have used an interdisciplinary approach that combines: (a) statistical analyses inspired by reliability modelling in engineering; (b) experimental studies of decisions of mammography experts using th...

Developments in computing offer experts in many fields specialised support for decision making under uncertainty. However, the impact of these technologies remains controversial. In particular, it is not clear how advice of variable quality from a computer may affect human decision makers. Here I review research showing strikingly diverse effects o...

The representativeness heuristic has been invoked to explain two opposing expectations--that random sequences will exhibit positive recency (the hot hand fallacy) and that they will exhibit negative recency (the gambler's fallacy). We propose alternative accounts for these two expectations: (1) The hot hand fallacy arises from the experience of cha...

To investigate the effects of incorrect computer output on the reliability of the decisions of human users. This work followed an independent UK clinical trial that evaluated the impact of computer-aided detection(CAD) in breast screening. The aim was to use data from this trial to feed into probabilistic models (similar to those used in "reliabili...

We studied the impact of a Computer Aided Detection (CAD) tool on human's decisions in mammography. We used data from an independent clinical trial, which compared the average performance of breast screening professionals with and without CAD. Standard analyses of these data showed no statistically significant effect of CAD's output on humans' canc...

The goal of the data collection and analyses described in this paper was to investigate the effects of incorrect output from a CAD tool on the reliability of the decisions of its human users. Our work follows on a clinical trial that evaluated the impact of introducing a computerised prompting tool (R2 ImageChecker) as part of the breast screening...

Abstract The goal of the ,data collection and analyses described in this paper was to investigate the effects of incorrect output from a CAD tool on the ,reliability of the ,decisions of its human users. Our work ,follows on a ,clinical trial that evaluated the impact ,of introducing ,a computerised prompting tool (R2 ImageChecker) as part of the b...

Legal decisions such as the decision to bail upon adjourning a case have major consequences for both defendants and society. In the English system, magistrates, most of whom are lay people, are afforded considerable discretion and must work under constraints such as time pressure. Judgment analysis of the bail decision making policies of 81 magistr...

Stanovich & West argue that their observed positive correlations between performance of reasoning tasks and intelligence strengthen the standing of normative rules for determining rationality. I question this argument. Violations of normative rules by cognitively humble creatures in their natural environments are more of a problem for normative rul...

The sunk cost effect is a maladaptive economic behavior that is manifested in a greater tendency to continue an endeavor once an investment in money, effort, or time has been made. The Concorde fallacy is another name for the sunk cost effect, except that the former term has been applied strictly to lower animals, whereas the latter has been applie...

The objective was to test whether individuals high in delusional ideation exhibit a reasoning bias on tasks involving hypothesis testing and probability judgments. On the basis of previous findings (e.g. Garety, Hemsley & Wessely, 1991), it was predicted that individuals high in delusional ideation would exhibit a 'jump-to-conclusions' style of rea...

Discusses the overconfidence phenomenon, which has been explained as a characteristic of human information processing and comments on papers from this special issue on stochastic and cognitive models of confidence. The papers presented here reflect 3 different general theoretical perspectives that can be labelled as Brunswikian, Thurstonian, and co...

Subjects playing the role of psychiatrists (actors) engaged in a simulated medical decision-making task in which they attempted to bring the value of a patient indicator variable into a desired range. For each treatment recommended by the actor, both the actor and an observer subject playing the role of a nurse assessed the probability that the tre...

Support theory (Tversky and Koehler, 1994) implies that different descriptions of the same event can prompt different subjective probabilities. More explicit descriptions are assumed to enable retrieval of stronger evidence prompting a higher subjective likelihood. In this paper bookmakers' odds are examined in relation to this hypothesis. British...

Given reliable statistical evidence, calculations of quantitative values of risk may be attempted. Novel technologies however are, by their nature, characterised by a lack of appropriate historical data which creates difficulties for conventional quantitative approaches to risk assessment. Numerical risk assessments which convey spurious validity a...

An ambiguous figure in the real world This photograph was taken at the Edinburgh Festival in 1992. The individual depicted is unknown but he was a street performer during the Arts Festival and this was his busking act. During the performance large numbers of people gathered and looked on with much amusement — clearly enjoying the effect. The fibres...

Risk is an inescapable fact of life. We are all confronted by risks; we all have to take risks whether we like it or not — whether we even know it or not. Although there has been a considerable effort to understand how — and how well — people react to threats there are still many unresolved arguments and uncertainties about the nature of risk. How...

The claim is frequently made that human judgement and reasoning are vulnerable to cognitive biases. Such biases are assumed to be inherent in that they are attributed to the nature of the mental processes that produce judgement. In this paper, we review the psychological evidence for this claim in the context of the debate concerning human judgemen...

a2 Department of Psychology, University College London, London WC1E 6BT, United Kingdom

This study investigates judgmental probability forecasting of nonpersonal events in the immediate and medium term. Forecasts for desirable events were found to be better calibrated and less overconfident in the immediate term than the medium term. Implications for decision analysis practice are discussed. In addition, forecasting responses and perf...

The widespread and unexceptional use of the term “expert” suggests that there is general public acceptance of the validity of the concept of an expert. For example, in news reports of particular “specialist” areas such as foreign politics, economics, and transport disasters, it is quite routine for particular individuals, presented as experts, to b...