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Institute of Criminology

History of psychology; sociology of the 'psy' professions; prisons; indeterminate sentences; punishment; legitimacy; power


I am an interdisciplinary researcher in psychology and criminology, with experience in both research and in applied psychology practice. My main interest is in the relationship between the ‘psy’ disciplines and criminal justice institutions, particularly those that punish. I am currently undertaking my PhD, studying the history and sociology of psychologists working in prisons, through exploration of historical archives, and interviews with psychologists who have worked in prisons. 

Before arriving at Cambridge, I spent nine years working in forensic psychological practice for the Prison Service in England/Wales. I conducted assessments of risk, need and ability, and delivered a range of psychological interventions. Latterly I specialised in working with men convicted of serious and repetitive violence. Much of my work was with men serving indeterminate sentences.

During my time in the Prison Service, I conducted research on the psychosocial characteristics of men who behaved violently in custody, and desisted over the course of their sentence. I was interested in how people managed to desist in an environment that typically has elevated levels of violence. 

In 2017, I moved to a Research Assistant post at the Institute of Criminology. For two years, I worked on the Families and Imprisonment Research (FAIR) Study: a 9 year mixed methods longitudinal study of imprisoned fathers, their partners and their children. Publications in progress include a methodological paper exploring contextual factors in longitudinal retention, and a paper exploring the relationship between imprisonment and post-release outcomes for families in which there is familial violence.

In 2019, I began my PhD with the Prisons Research Centre, looking at how psychology is practiced in prisons. I am especially interested in the social and cultural features of prison-based psychology, how psychologists navigate the complex moral landscape of prison, and how psychologists’ notions of their legitimacy and ‘moral selves’ influence their work with prisoners. 

I am also interested in prisoners' and prison staff's experiences of 'psy' influenced practices, including risk assessment, treatment programmes, psychological consultancy and rehabilitative culture practices, particularly for those serving (and working with those who are serving) indeterminate sentences. 


Key publications: 


Ellis, S., Lanskey, C., Markson, L., Souza, K., Barton-Crosby, J. & Lösel, F. (under review). Retaining participants in longitudinal studies: The role of spatial and temporal considerations. International Journal of Social Research Methodology.

Souza, K., Lanskey, C., Ellis, S., Markson, L., Lösel, F., & Barton-Crosby, J. (under review). A comparison of the physical and mental health of male prisoners and their female (ex)partners from pre- to post-release. Criminal Behavior and Mental Health. 

Ellis, S. and Bowen, E. (2017). Factors associated with desistance from violence in prison: An exploratory study. Psychology, Crime and Law, 23, 1-19.


Conference Presentations:

Ellis, S., Lanskey, C., Souza, K., Markson, L., Löesel, F., & Barton-Crosby, J. (2020, March). Families after prison: What are they like, and how do they experience probation? Paper presented at the Probation Institute Conference, London: UK. 

Ellis, S., Lanskey, C., Loesel, F., Markson, L., Souza, K., & Barton-Crosby, J. (2019, June). Families affected by paternal imprisonment in the UK: Ethnic and cultural perspectives. Paper presented at the Families and Imprisonment Research Conference, Cambridge: UK.


Markson, L, Ellis, S., Lanskey, C., Barton-Crosby, J. & Losel, F. (2018, November). Long-term experiences of addiction for previously imprisoned fathers. Paper presented at the American Society of Criminology Annual Conference, Atlanta.  


Ellis, S., Losel, F., Lanskey, C., Markson, L & Barton-Crosby, J. (2018, August). Transience, transition and trust: Themes from participant retention in the Families and Imprisonment Research Study. Paper presented at the European Society of Criminology Annual Conference, Sarajevo.


Ellis, S., Losel, F., Lanskey, C., Markson, L & Barton-Crosby, J. (2018, June). Transience, transition and trust: Themes from participant retention in the Families and Imprisonment Research Study. Paper presented at the Division of Forensic Psychology Annual Conference, Newcastle.


Ellis, S. (2018, June). Violence prevention in prisons: The gap between theory, practice and lived experience. Paper presented at the Center for Violence Prevention Annual Conference, Worcester.


Ellis, S. and Bowen, E. (2017, June). Factors associated with desistance from violence in prison: An exploratory study. Paper presented at the 26th Division of Forensic Psychology Annual Conference, Bristol: United Kingdom.


Other publications: 


Ellis, S. (2018). Why the public needs to force a conversation with the Government about prisons. i. Retrieved from


Ellis, S. (2018). Prisons will only improve if the public demands change. The Conversation. Retrieved from

Ellis, S. (2017). Psychologists call for research into Universal Basic Income. Retrieved from

Ellis, S. (2017). No alternative facts, just alternative hypotheses. (Coverage of the March for Science event in April 2017). Retrieved from

Ellis, S. (2008). The contribution of the study of visual illusions to our understanding of the processes involved in visual perception. Psych-Talk, 61, 21-27.

Teaching and Supervisions



Institute of Criminology, Cambridge:

2020: HSPS Tripos: Foundations of Criminology and Criminal Justice: Risk Assessment & Algorithmic Justice lecture. 

2019 & 2020: MPhil Criminological Research Methods module: NVivo workshop.


University of Suffolk:

2018 - 2020: Forensic Psychology module - guest lecturer. 

Research supervision: 


I provide ad-hoc consultancy to forensic psychology trainees completing research as part of their qualification portfolio. 

Other Professional Activities


2020-2021: Co-opted member of the Division of Forensic Psychology committee: British Psychological Society. 

Contact Details

+44 (0)1223 767367


Darwin College