Rachel Stephens

Dr Rachel Stephens

Senior Lecturer

School of Psychology

Faculty of Health and Medical Sciences

Eligible to supervise Masters and PhD - email supervisor to discuss availability.

Research Areas: Human reasoning and decision making, reasoning aids, online influence, reasoning development

I am a Cognitive Scientist and Director of the Reasoning and Decisions Lab. My research focuses on testing the cognitive processes that drive human reasoning and decision-making, with the overarching question: how do people draw conclusions or make decisions, based on new and existing knowledge? I seek to understand the strengths of human thinking and also the situational and cognitive factors that can lead to errors and biases in thinking. This will inform the development of interventions (e.g. reasoning aids or training) that can help people to reason more effectively.

Research program: Testing dual-process and single-process reasoning theories

One of my current main lines of research is testing influential dual-process theories, which propose that human reasoning and judgement is driven by two qualitatively different kinds of cognitive processes: One is often characterized as fast and intuitive, while the other is described as slow and deliberative. A major project I am working on with Prof. Brett Hayes (University of New South Wales) and Prof. John Dunn (University of Western Australia) involves testing whether dual-process theories are needed to account for reasoning across a range of contexts, such as when people are put under time pressure, are preoccupied with other tasks, or are faced with different task instructions. An important finding of our work has been that despite the popularity of dual-process theories, simpler single-process theories have not yet been ruled out. This suggests that the dual-process distinction may be unwarranted. We have recently begun exploring how these competing theories account for developmental changes in reasoning across childhood.

Research program: Monitoring And Guarding the Public Information Environment (MAGPIE)

Another ongoing branch of my research with Dr Keith Ransom, Prof. Carolyn Semmler, Prof. Lewis Mitchell, Prof. Andrew Perfors, (University of Melbourne) and others examines how people navigate online information environments such as social media. We are interested in how people's beliefs and attitudes are influenced by information on social media and the factors that drive associated behaviours, including information sharing and seeking. We aim to help build resilience against challenges in online environments including misinformation, influence campaigns, and echo chambers. In one major line of research, we are investigating how people perceive the level of consensus in a given claim on social media. This is a complex reasoning problem because the independence of sources and original evidence is often unclear. We have received funding from Defence Innovation Partnership, Advanced Strategic Capabilities Accelerator, and the University of Adelaide's Digi+ FAME scheme to develop digital tools that can help people to understand the structure of online information and calibrate their beliefs appropriately against the available evidence. See our Research News article: Mitigating misinformation on social media.

 

PhD, Masters, Honours, or Intern Research Projects

Please contact me if you are interested in any of these projects:

  1. Theoretical or applied research on reasoning from social consensus, including in online social media environments.
     
  2. Theoretical or applied research in reasoning and decision making, including under time-pressure or in high-stakes situations. Applied research includes investigating how people assess the healthiness of foods based on their labels (Nutrition Information Panel, etc.).
     
  3. Training reasoning and critical thinking skills in educational or occupational settings.
     
  4. Developing and testing reasoning aids, such as the fact-checking tags on social media.
     
  5. Exploring developmental changes in the reasoning of children or older adults.
     

  • Appointments
    Date Position Institution name
    2024 - ongoing Psychology Research Chair University of Adelaide
    2023 - ongoing Senior Lecturer University of Adelaide
    2022 - 2023 Psychology Research Deputy Chair University of Adelaide
    2019 - 2022 Lecturer University of Adelaide
    2015 - 2019 Postdoctoral Research Fellow University of New South Wales
    2014 - 2015 Postdoctoral Research Fellow Syracuse University
    2012 - 2014 Lecturer University of Adelaide

  • Awards and Achievements
    Date Type Title Institution Name Country Amount
    2025 Award John Keats Early Career Award Australian Society for Mathematical Psychology Australia -
    2022 Teaching Award Executive Dean's Teaching Excellence Award University of Adelaide Australia -
    2020 Teaching Award University of Adelaide Special Commendation - COVID 19 Emergency Teaching Response University of Adelaide Australia -
    2019 Teaching Award Executive Dean's Team Award University of Adelaide Australia -
    2013 Teaching Award Executive Dean's Learning & Teaching Prize University of Adelaide Australia -
    2009 Teaching Award School of Psychology’s Excellence in Teaching Award University of Adelaide Australia -
    2007 Scholarship Australian Postgraduate Award Australian Federal Government Australia -

  • Education
    Date Institution name Country Title
    University of Adelaide Australia PhD in Psychology
    University of Adelaide Australia Bachelor of Psychology (Honours)

  • Research Interests
    Cognitive Science Decision Making Experimental Psychology Psychology and Cognitive Sciences Simulation and Modelling
2025 Keith Ransom, Lucia Falzon, Jigar Patel, Mark Krieg, Lewis Mitchell, Rachel Stephens, Andrew Perfors, Shanika Karunasekera.
Emerging and Disruptive Technologies Program, Advanced Strategic Capabilities Accelerator. $2,861,186.
Project: ‘Conductor’: Detecting, understanding, and countering synthetic influence campaigns.
2025 Andrew Cunningham, Keith Ransom, Marian-Andrei Rizoiu, Lewis Mitchell, Rachel Stephens, James Walsh, Wolfgang Mayer, Carolyn Semmler, Melissa Humphries. 
Emerging and Disruptive Technologies Program, Advanced Strategic Capabilities Accelerator. $2,879,502.
Project: ANVIL: A Narrative Analysis and Visualisation Toolkit for AI Disinformation Campaigns.
2023 Dr Keith Ransom, Prof Lewis Mitchell, Prof Carolyn Semmler, & Dr Rachel Stephens.
Developing Situational Awareness in the Information Environment, Defence Science & Technology Group. $100,000.
Project: RMANDO: Rhetorical Mapping and Narrative Detection Online.
2023 Rachel Stephens.
Barbara Kidman Women's Fellowship, University of Adelaide. $30,000, 12 months.
2022 Rachel Stephens, Keith Ransom, Rachel Searston, Zygmunt Szpak, Fernando Marmolejo-Ramos, Dragana Pittas.
Collaborative Research Fund, Defence Innovation Partnership.  $150,000, 12 months.
Project: Advancing SOCRETIS (“SOCial REasoning Tool & Interactive System”): An AI-enabled collaborative reasoning aid for the information environment.
2022 Rachel Stephens.
Emerging Leaders Development Award, Faculty of Health and Medical Sciences, University of Adelaide. $40,000, 9 months.
Project: Characterising the processes of thinking fast and slow.
2022 Keith Ransom, Rachel Stephens, Carolyn Semmler & Lewis Mitchell.
In association with: Andrew Perfors & Christopher Leckie.
Digi+ FAME program (Information Capability mission), University of Adelaide.  $99,050, 18 months.
Project: MAGPIE: Monitoring And Guarding the Public Information Environment.
2021 Zygmunt Szpak, Wojciech Chojnacki, Rachel Stephens, Keith Ransom & Rachel Searston.
AI for Decision Making Program Round 2, Department of Defence and the Office of National Intelligence, delivered in partnership with the Defence Innovation Partnership in South Australia.  $100,000, 6 months.
Project: A tool for human-in-the-loop contextual anomaly detection. 
2020 Rachel Stephens & Keith Ransom.
AI for Decision Making Program, Department of Defence and the Office of National Intelligence, delivered in partnership with the Defence Innovation Partnership in South Australia.  $20,000, 3 months.
Project tile: Testing human responses to AI fact-checking and uncertainty. Project ID: 167650398

I have extensive experience in undergraduate teaching in cognitive psychology, research methods, and statistics.

I am Course Coordinator for Psychology 1A and Psychology 1B. I also teach into Research Methods in Psychology (level 1) and have been developing new courses for Adelaide University on individual psychology. I previously taught statistics in Doing Research In Psychology (level 2).

  • Current Higher Degree by Research Supervision (University of Adelaide)
    Date Role Research Topic Program Degree Type Student Load Student Name
    2025 Co-Supervisor The interaction of psychological, linguistic, and platform dynamics in shaping the conspiratorial misinformation ecosystem in digital environments Doctor of Philosophy Doctorate Full Time Miss Rituparna Mukherjee
    2024 Principal Supervisor Reasoning from consensus: exploring perceptions of the value of consensus quality information in online reasoning. Doctor of Philosophy Doctorate Full Time Mr Joseph Higginson
    2024 Co-Supervisor Quantifying Online Persuasibility: Analysis, Metrics Development, and Application in Digital Discourse Master of Philosophy Master Full Time Mr Gia Bao Hoang
    2024 Co-Supervisor The effects of parasocial relationships on social media engagement, trust, pro-social behaviour, and social and political activism. Doctor of Philosophy Doctorate Full Time Ms Nicolle Cassandra Kelaiditis
    2024 Principal Supervisor Enhancing Resilience to Misinformation through Tailored Interventions Doctor of Philosophy Doctorate Part Time Mr Steven Edward Davis
    2023 Principal Supervisor An exploration of the influence of cues to consensus quality on online reasoning and behaviour. Doctor of Philosophy Doctorate Full Time Mr Benjamin Paul Simmonds
    2022 Principal Supervisor Sharing Misinformation: The Socio-Psychological Mechanisms of Spread Doctor of Philosophy Doctorate Full Time Miss Emily Brooke Mullins
    2022 Principal Supervisor Iterative decision-making with ethical considerations Doctor of Philosophy under a Jointly-awarded Degree Agreement with Doctorate Full Time Mr Vincent Bebien

  • Other Supervision Activities
    Date Role Research Topic Location Program Supervision Type Student Load Student Name
    2022 - 2022 Principal Supervisor The effect of perceptions of consensus and expertise in health reasoning University of Adelaide - Honours - Nusrat Asad
    2022 - 2022 Principal Supervisor The effect of perceived expertise and consensus on health-related information sharing University of Adelaide - Honours - Benjamin Simmonds
    2022 - 2022 Principal Supervisor Testing theories of reasoning using the base-rate task University of Adelaide - Honours - Alexander Sikora Przibilla
    2022 - 2022 Co-Supervisor Examining how people detect scam SMSes University of Adelaide - Honours - Angus Stilwell
    2021 - 2022 Co-Supervisor Testing memory effects in social reasoning University of Adelaide - Honours Full Time Bryan Banks
    2021 - 2021 Principal Supervisor Testing theories of transitive reasoning University of Adelaide - Honours Full Time Nadia Scott
    2021 - 2021 Principal Supervisor Testing reasoning aids for social meta-inference University of Adelaide - Honours Full Time Hannah Le Leu
    2020 - 2020 Principal Supervisor Testing dual-process theories of reasoning development The University of Adelaide - Honours - Minling Tan
    2020 - 2020 Principal Supervisor Testing cognitive theories of nutrition judgements based on food labelling The University of Adelaide - Honours - Seok-Jun Kang
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