Ciarán James O'Keeffe (born 21 March 1971) is a British applied psychologist and academic who investigates paranormal claims from a sceptical perspective, best known for his role as the resident sceptical investigator on Most Haunted. Rather than simply debunking, his published research asks broader questions — why people report uncanny experiences, how environments shape those interpretations, and what ethical duties investigators owe to the witnesses they study.[1]
Early life
O'Keeffe was born in Norwich to a Swiss mother and an Irish father, and grew up in Norfolk, Somerset, and High Wycombe, Buckinghamshire. He has cited Edgar Allan Poe and H. P. Lovecraft among his favourite authors, and named the television series Arthur C. Clarke's Mysterious World and the Ghostbusters films as early influences on his interest in the paranormal.
Academic career
O'Keeffe studied music and psychology at Washington College in Maryland, before completing a master's degree in investigative psychology at the University of Liverpool. He earned his PhD in psychology at the University of Hertfordshire in 2005, supervised by Richard Wiseman, with a research programme assessing the content of advice given by practitioners claiming paranormal abilities.[1] He previously lectured in psychology at Liverpool Hope University, and is currently an associate professor at Buckinghamshire New University. He is a member of the Society for Psychical Research and an advisor to The Ghost Club.
Hampton Court Palace investigation
O'Keeffe was part of an academic team, working alongside Wiseman, that investigated Hampton Court Palace — reputed to be one of the most haunted locations in England — to test three competing explanations for reported hauntings there: prior belief in ghosts, suggestion, and magnetic fields. More than 600 members of the public took part, completing questionnaires on their belief in ghosts before being given either a positive or negative "suggestion" about recent unusual activity at the palace and encouraged to walk its rooms reporting anything they experienced. The study found reported experiences were significantly associated with both prior belief and the suggestion given beforehand, and the data offered some support for a relationship between local magnetic field variation and where experiences were reported.[1]
Environmental correlates of hauntings
In 2020, O'Keeffe and colleagues published a comprehensive review updating earlier 2001 work on the environmental correlates of poltergeist and haunting experiences, examining 66 studies across two decades of research. The review identified six recurring environmental variables proposed to contribute to haunting reports — embedded static cues, lighting levels, air quality, temperature, infrasound, and electromagnetic fields — but concluded that none of these, alone or combined, offered convincing explanatory power on their own, pointing instead toward more holistic explanations such as "simulation theory" as a more productive way to understand reported hauntings.[1]
"Ghostwatch Revisited"
In a 2012 article marking its twentieth anniversary, O'Keeffe examined the notorious 1992 BBC broadcast Ghostwatch, a scripted drama presented as a live investigation that caused significant public panic and was linked to a viewer's death by suicide. Sceptic Susan Blackmore, quoted in the piece, criticised the programme for treating its audience unfairly and failing to give adequate warning of its content. O'Keeffe concluded that the extreme viewer reactions stemmed from the programme's departure from established horror-genre convention — where the instability caused by a paranormal threat is eventually resolved — since Ghostwatch instead sustained its threat continuously throughout.[1]
Quantifying ghostly encounters
In a wide-ranging review with co-authors, O'Keeffe helped identify 28 core experiences commonly reported across haunting and poltergeist cases, spanning both subjective experiences typical of hauntings and the more physical, objective manifestations typical of poltergeist-type disturbances, aiming to give future investigators a more standardised framework than existing case studies, surveys, and field research had provided.[1]
Ethical guidelines for haunting investigations
In a 2007 paper co-authored with Ian Baker, O'Keeffe set out ethical guidelines for haunting investigations, prompted by the rapid growth of amateur and professional ghost-hunting activity and the absence of any governing body for the field. The guidelines address informed consent and confidentiality, offer methodological advice on interviewing and overnight location investigations, and examine the pastoral responsibilities an investigator owes to witnesses, including when to refer them to other professional support.[1]
Testing mediums
In a 2005 paper with Richard Wiseman, O'Keeffe reported a double-blind test of mediumship designed to eliminate flaws identified in earlier research — sensory leakage, overly general statements, and non-blind judging. Five mediums each gave a reading to a sitter unknown to them, located in a separate room; sitters were then given the resulting statements, broken apart and mixed with material from other sittings, and asked to identify which applied to them. The ratings did not reach statistical significance.[1] A later 2020 review by researcher Patrizio Tressoldi, examining more recent and methodologically rigorous mediumship tests generally, reported finding highly significant evidence for anomalous information transfer — a conclusion in tension with O'Keeffe and Wiseman's own earlier null result.[1]
"Haunted People Syndrome"
O'Keeffe and co-authors have also explored whether a distinct "Haunted People Syndrome" (HP-S) exists — a pattern of recurrent, systematic anomalous perceptions that, depending on the person's interpretive framework, might be understood as spirits and hauntings, or might instead take the form of perceived gang-stalking or surveillance. Rating published gang-stalking accounts against a standard measure of haunt-type anomalies, the researchers found significant overlap between the two categories of experience, consistent with a single underlying HP-S construct.[1]
Most Haunted
O'Keeffe joined Most Haunted as its parapsychologist, replacing Phil Whyman, and became known for providing a sceptical, evidence-based counterpoint to the show's on-camera investigations. In 2005, he devised a test in which he fed Derek Acorah fabricated background details about entirely fictitious spirit entities — "Kreed Kafer" and "Rik Eedles," anagrams of "Derek Faker" and "Derek Lies" — before an investigation. Acorah went on to describe contact with them on camera as though they were real, and O'Keeffe's exposure of the test became one of the best-known moments in British paranormal television.
O'Keeffe later said he had been misquoted in press coverage of the incident, clarifying that his test had been aimed specifically at Acorah rather than at the programme or its wider team.
Books
O'Keeffe co-authored Ghost Hunters: A Guide to Investigating the Paranormal (2006) with Yvette Fielding, drawing on cases from their own investigations alongside a broader guide to hauntings, orbs, and poltergeists. The pair also co-authored In Search of the Supernatural (2008), investigating paranormal sightings across the UK and abroad, including the tunnels beneath Liverpool and the Devil's Arse cavern in the Peak District. Separately, O'Keeffe co-authored The Great Paranormal Clash (2008) with stage psychic Billy Roberts, structured as an exchange of opposing perspectives between the two.[1]
See also
- Most Haunted
- Derek Acorah
- Yvette Fielding
- Richard Wiseman
- Ghostwatch
- Ghost Hunters: A Guide to Investigating the Paranormal