If you wanted to summarise the most important mediumship studies of the past two decades – Schwartz/VERITAS, Beischel/Windbridge, Roy & Robertson/Glasgow, Lazar/EREAMS – at one glance, there is one person you cannot avoid: Dr. Patrizio Tressoldi of the Università degli Studi di Padova. The Italian psychologist and consciousness researcher published a meta-analysis with colleagues in 2020 that does exactly that: it aggregates 18 mediumship experiments from 14 peer-reviewed publications between 2001 and 2019 into a single statistical picture. The result is a number that is hard to ignore:
p < 10⁻⁹
The probability that the effects observed across this body of research arose by pure chance is therefore less than one in a billion.
Who Is Patrizio Tressoldi?
Patrizio Tressoldi is a senior researcher at the Università degli Studi di Padova – one of the oldest universities in Europe, founded in 1222 and once the academic home of Galileo Galilei. His scientific anchoring lies in mainstream psychology; his research focus in the borderlands of consciousness. At the university he leads the Science of Consciousness Research Group (also known as Studium Patavinum), which investigates anomalous psychological phenomena with experimental rigour.
Tressoldi works far beyond mediumship: on presentiment (physiological pre-responses to future stimuli), remote viewing, out-of-body experiences, and more recently on shared death experiences. This breadth is methodologically important – it makes him an overarching observer of an entire research field, not just of a single phenomenon.
What Is a Meta-Analysis – and Why Does It Matter Here?
A meta-analysis systematically aggregates the results of multiple individual studies and computes a combined effect from their effect sizes. Instead of looking at a single study in isolation, it asks: what does the body of evidence show as a whole? This procedure is the gold standard in evidence-based medicine – it determines whether a drug gets approved or not.
In mediumship research, such an aggregation was long overdue. Any single study – even a very clean one like the quintuple-blind work by Beischel – can in principle still be explained away by random configurations or a lucky sample. Only the bundling of multiple independent experiments shows whether a consistent signal is present.
The 2020 Meta-Analysis
The study "Anomalous information reception by mediums: A meta-analysis of the scientific evidence" appeared in 2020 in the peer-reviewed journal EXPLORE: The Journal of Science and Healing. Tressoldi and his co-authors analysed:
- 14 peer-reviewed publications between 2001 and 2019
- 18 independent experiments
- Studies with double-, triple-, and even quintuple-blind protocols
The aggregated outcome: a combined effect with a chance probability of p < 10⁻⁹. This places the effect at a level that mainstream medicine or psychology would describe as "overwhelming evidence" – a drug efficacy at p < 10⁻⁹ would be approved without delay.
Publication Bias Ruled Out
Skeptics often accuse positive research fields of suffering from publication bias – meaning negative studies stay in the drawer while only positive ones get published. Tressoldi addressed exactly this concern. Using two standard statistical tests, he checked for evidence of selective publication. Both tests found no signs of systematic distortion.
One of the central skeptic responses – "there must be many negative studies that were never published" – is therefore neutralised within the data themselves. The overall result can no longer be dismissed by pointing to a hidden drawer of failures.
The 2022 OMEGA Study
Tressoldi does not stop at the meta-analysis. He continually extends the data with his own experimental research. A particularly notable study appeared in 2022 in OMEGA – Journal of Death and Dying: "Is There Someone in the Hereafter? Mediumship Accuracy of 100 Readings Obtained with a Triple Level of Blinding Protocol" (Tressoldi, Liberale & Sinesio):
- 28 mediums
- 100 readings under triple-blind conditions
- Sitters had to distinguish actual readings from decoy readings
- Result: p = 0.000048 – about one in 20,000
Survival, Not Just "Psi"
In an earlier study from 2021 ("Mediumship accuracy: A quantitative and qualitative study with a triple-blind protocol"), Tressoldi went one step further and asked the philosophically delicate question: does the information come telepathically from the sitters, or actually from the deceased? Nine mediums produced 38 readings about 38 deceased individuals; the medium was given only the deceased's first name. The qualitative analysis – specificity to concrete biographical details of the deceased rather than the emotional state of the sitters – led to a noteworthy conclusion in the field:
The data support the survival hypothesis more strongly than the pure psi/telepathy hypothesis.
In doing so, Tressoldi positions himself more boldly than, for instance, Beischel, whose "Anomalous Information Reception" framing deliberately leaves the survival question open. Tressoldi argues that the specificity of the hits on the deceased – not on the sitters present – forces one to take the survival explanation seriously.
Putting It in Context: The Capstone of the Series
Tressoldi's work has a different function from that of the other researchers in this series. Schwartz, Beischel, Roy/Robertson, and Lazar studied mediums individually – Tressoldi looks at the research landscape as a whole:
- Schwartz/VERITAS provided the methodological starting point.
- Roy & Robertson/Glasgow brought larger samples.
- Beischel/Windbridge tightened the blinding to five layers.
- Lazar/EREAMS added a German, qualitative-hermeneutic line.
- Tressoldi aggregates them all – and shows that the signal is consistent, robust, and independent of the bias of any single research group.
With p < 10⁻⁹ across 18 independent experiments over two decades, mediumship research is in a state that one would expect for a phenomenon that actually exists – not for one produced by accumulated self-deception or publication bias. The scientific question has shifted accordingly: no longer "is there something there?", but "how do we explain what is there?"
Sources:
• P. Tressoldi et al., Anomalous information reception by mediums: A meta-analysis of the scientific evidence, EXPLORE: The Journal of Science and Healing (2020).
• P. Tressoldi, L. Liberale et al., Mediumship accuracy: A quantitative and qualitative study with a triple-blind protocol (2021).
• P. Tressoldi, L. Liberale & F. Sinesio, Is There Someone in the Hereafter? Mediumship Accuracy of 100 Readings Obtained with a Triple Level of Blinding Protocol, OMEGA – Journal of Death and Dying (2022).
• Psi Encyclopedia (SPR): Patrizio Tressoldi.
• University of Padova: Patrizio Tressoldi.
The individual studies that Tressoldi brings together in his meta-analysis are covered in our articles on Gary Schwartz and VERITAS, Roy & Robertson's Glasgow Study, Julie Beischel and the Windbridge Institute, and the EREAMS study by Oliver Lazar.