Rachel moved into the study of Law from a successful career in academic science in the area of cancer biology and bacterial genetics. She 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.
Rachel then changed discipline and completed an LLB in Cardiff in 2007 and was awarded a PhD in law in 2016. Her 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 40.4 (2013): 596-623. Other prizes include the SLS Poster Prize 2012 with " Do Personal Values Tip the Scales of Justice?" and the SLSA Poster Prize 2012 for her work entitled "Personal Values: An Important Element in the Diversity Debate" This work underpins hercollaborative comparative work on the High Court of Australia.
Her interests lie in decision making and facets of personality that influence decision making. She collaorates 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.
Dr Cahill-O'Callaghan also has research interests in judicial appointments and conceptions of merit.