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Rachel Cahill-O'Callaghan   PhD (Law), PhD (Science), LLB, BSc, Dip Stat

Professor Rachel Cahill-O'Callaghan


PhD (Law), PhD (Science), LLB, BSc, Dip Stat

Professor, Director of Research (Law)

School of Law and Politics

+44 29208 74479
Law Building, Floor First , Room 1.12, Museum Avenue, Cardiff, CF10 3AX
Available for postgraduate supervision


PhD (Law), PhD (Science), LLB, BSc, Dip. Dietetics, FHEA, Dip Statistics.

Values in the Supreme Court. Decisions, Division and Diversity (Hart Publishing 2020) Shortlisted for the Birks Book Prize (2020)

Latest Paper: Cahill-O'Callaghan, R. and Roberts, P. 2023. Hearing the voice of the woman judge: Diversity, equality, and participationDickinson Law Review 127(3), 735.

I moved into the study of Law from a successful career in academic science in the area of cancer biology and bacterial genetics. I completed a PhD in Science in 1994 at Trinity College (Dublin) and moved to Massachusetts Institute of Technology (Boston) and then to Imperial College (London). This work is widely published and won several international prizes.

I then changed discipline and completed an LLB in Cardiff in 2007 and was awarded a PhD in law in 2016. My legal research, which combines theories and techniques from psychology and law, has also won awards including  the SLS Best Paper Prize (2014)  with  "Reframing the Judicial Diversity Debate: Personal Values and Tacit Diversity." which is published in  Legal Studies (2015) 35(1) 1-29 .  Other prizes include the SLS Poster Prize 2012 with " Do Personal Values Tip the Scales of Justice?"  and the SLSA Poster Prize 2012 for  "Personal Values:  An Important Element in the Diversity Debate."  This work underpins my collaborative comparative work on the High Court of Australia and work on legal decisions in medical law.  I also research judicial appointments and conceptions of merit.

My overarching interests lie in decision making and facets of personality that influence decision making.  I collaorate with academics in the UK and US to examine decision making with law students in an international study examining the influence of values and other indicators of professionalism on ethical decision making. I have also researched the policy decisions surrounding fertility treatment in the UK. In recent times, I have brought my two career paths together, examining the legal frameworks in the field of genomics.










Adrannau llyfrau





My research explores the influence of facets of personality on legal decision making.   My primary focus is on the influence of personal values in legal judgments and the implications for decision making and diversity.  This work draws on theories and techniques from psychology to examine decision making in cases which divide judicial opinion in the UK Supreme Court.  The work has won several prizes including winning the Society of Legal Scholars best paper prize 2014 with Cahill-O'Callaghan, R. (2015). Reframing the judicial diversity debate: personal values and tacit diversity. Legal Studies 35(1) 1-29.   This research was cited by Lord Mance (Supreme Court) in his lecture during the Judicial Committee of the Privy Council’s sitting in the Bahamas on 24 February 2017. The content analysis technique I developed to identify values in legal judgments is detailed in Cahill-O'Callaghan, R. (2013). The influence of personal values on legal judgments. Journal of Law and Society 40(4) 596-623.   This paper was one of three papers short-listed for the Socio-Legal Scholars Association Best Paper Prize 2014. My monograph 'Values in the Supreme Court: Decisions, Division and Diversty (Hart 2020) was shortlisted for the SLS Birks Book prize 2020.

Another strand of my work centres on comparative judicial studies, examining judicial decision making  in two other ultimate courts, the  US Supreme Court and the High Court of Australia. I have used the value methodology to examine the values that underpin political decision making in the US Supreme Court, in the paper Beneath Politics: Values in the US Supreme Court.  I also work with Heather Roberts (ANU) to examine the values and facets of judicial personality which are revealed in swearing-in speeches of the judiciary of the High Court of Australia.

I also work with Richard Moorhead (UCL), Stephen Galoob (Tulsa), Maryam Kouchaki (Kellog) on law student ethical decision making. This research " Values, ethics and professionalism in Law School"  was funded by the Legal Education Foundation (£26,000) and the SAFRA Foundation Harvard University ($10,000). This collaborative multidisciplinary project explores the relationship between values, professionalism and ethical decision making in law students from both the UK and US.   The first publication from this work is Moorhead, R; Denvir, C; Cahill-O'Callaghan, R; Kouchaki, M; Galoob, S (2016) The Ethical Identity of Law Students. International Journal of the Legal Profession 6; 1 – 41.

My work on policy decision making centres on judicial appointments, and the role of single persons in artificial reproductive technology in work with Dr. Atina Krajewska (Birmingham University) which  is funded by British Academy.  My work on judicial appointments centres on judicial appointments in the Welsh context.

Other judicial studies interests include implicit bias,  decisions on case selection in the Supreme Court, conceptions of merit and the role of dissent.


External Funding

  • 2016  Co-applicant  "Single persons in publically funded fertility treatment in the UK - Should we care? British Academy Awarded Value: £4,907. Principle applicant: Dr. Atina Krajewska, (Birmingham University).
  • 2014 – 2015 Co-applicant " Do Values and Professionalism Change During Law School?”" Legal Education Foundation: Robust Evidence Awarded Value: £21,000.  Principle applicant: Prof. Richard Moorhead (Centre of Professional Ethics, University College London, QS 7)Co-applicant:   Dr. Maryam Kouchaki, (Kellog School of Management, Northwestern University, QS 26)Co-applicant:  Dr. Stephen Galoob ( College of Law, University of Tulsa, QS 701)
  • 2014 – 2015 Co-applicant “Do Values and Professionalism Change During Law School?”  SAFRA Foundation Harvard University (US) Awarded Value: $10,000. Principle applicant:   Dr. Maryam Kouchaki, (Kellog School of Management, Northwestern University QS 26) Co-applicant: Prof. Richard Moorhead (Centre of Professional Ethics, University College London, QS 7)Co-applicant:  Dr. Stephen Galoob ( College of Law, University of Tulsa, QS701))

Institutional Grant Funding

  • 2018 Joint application with Dr. Bernadette Rainey – Finding work: An exploration of low paid work in Cardiff – Cardiff University Research Opportunities Programme. Awarded Value £1,600
  • 2016 Sole Applicant “ The Judiciary in Wales : A Unique Diversity Concern.”  Cardiff  University Research Opportunities Programme. Awarded Value: £1,600
  • 2013 Sole Applicant “The Cases the Supreme Court Reject.”  Cardiff University Research Opportunities Programme Awarded Value: £1,460


I am the lead and teach the undergraduate modules Land Law and Dissertation and the postgraduate module Empirical Studies in Law.   I have also taught Tort Law.


My path to law, like my research, does not follow the established patterns.  I came to law from science having completed a PhD in clinical medicine at Trinity College, Dublin in 1994.  This was followed by two postdoctoral fellowships at MIT (1994 – 1998) and Imperial College London (1998 – 2002). My legal research combines facets of both disciplines, drawing on theories and techniques from science to understand legal questions.

I was appointed to a lectureship post at Cardiff School of Law and Politics during my PhD studies (2012).  I was awarded my PhD in Law in 2016. On the basis of my research, teaching and engagement with the profession I was promoted to Senior Lecturer (2017) and Reader in 2019.

Honours and awards

Shortlisted for the SLS Birks Book Prize for the monograph 'Values in the Supreme Court: Decisions, Division and Diversity' (Hart 2020)

Best Paper (2014) Society of Legal Scholars (SLS)

Short list final three Best Paper Prize (2014) Socio-Legal Scholars Association (SLSA)

Winner Best Poster Prize (2013) Society of Legal Scholars (SLS)

Winner Best Poster Prize (2012) Socio-Legal Scholars Association

Prior to my change of discipline, I received ten European awards and one American award, including the best presentation at the American Gastroenterology Society.

Professional memberships

Fellow, Higher Education Academy

Member of Socio-Legal Studies Association

Council member of Society of Legal Scholars

Member of Society of Empirical Legal Scholars (US)

Member of the Law and Society Association (US)

Member of the American Association of Advancement of Science (US)

Invited member of the Australian Research Council Expert Panel (National Competitive Grants Programme Discovery and Linkage Programme)

Invited Member of the LSA Collaboration Network on Judicial Studies

Invited Member of the LSA Collaboration Network on Law and Emotion

Academic positions

2019 - Reader, Cardiff University

2017 – 2019 Senior Lecturer, Cardiff University

2012- 2017:Lecturer in Law , Cardiff University

2010 - 2012 : Cardiff Law School PhD Scholarship

2000-2003: Lecturer (Part-time), Molecular Microbiology, Birkbeck University, London

1999 - 2003: Post - Doctoral Fellow, Centre of Molecular Microbiology, Imperial College

1994-1998: Post- Doctoral Fellow, Comparative Medicine, MIT (USA)

1990 – 1994: PhD Scholarship, Trinity College, Dublin

Committees and reviewing

Council Member,  Society of Legal Scholars (SLS)

Steering Committee Member Centre of Law and Society

Assistant Editor Journal of Law and Society

Reviewer: I review for a range of journals including the Modern Law Review, UNSW Law Journal, Law & Society Review, Legal Studies.



I am welcome PhD student applications in sociolegal studies with a focus on the legal profession and decision-making.  I will also consider research in law and science and implicit bias.



Current supervision

Emma-Rose McKeown

Emma-Rose McKeown

Research student

Past projects

I have supervised 

Dr. Lauren Cooper in the area of experiences of actors in asylum appeals

Dr. Kevin Williams in the area of housing policy in Wales