A quantitative digest of the ESP-Nexus structured study database for Forced-Choice ESP: 16 studies spanning 1991–2024, with every figure traceable to its source. ESP-Nexus reports what the studies found and takes no position on whether the effects are genuine.
Across four meta-analyses and numerous primary studies spanning 1991 to 2024, the quantitative picture for forced-choice ESP is decidedly mixed. Pooled effect sizes are small: Storm (2023) reported ES 0.02 (z/sqrt-n) across 141 studies, Steinkamp (1998) found ES 0.01 (z/sqrt-n) across 22 studies, and Milton (1999) obtained ES -0.0046 (z/sqrt-n) across 8 mass-media tests. One outlier, Rock (2023), reported a substantially larger ES of 0.39 (Cohen's d), though its scope differs from the others. Primary studies range widely: Radin (2019) produced z = 11.28, Laythe (2024) reached p = .0058, and Schmidt, Conrad & Walach’s mirror experiment reached ES 0.159 (as tabulated in Ambach’s 2012 commentary), while Houran (2024), Billows (2015), Rey (2010), and Schmidt (2012) returned null results, and Berger (1991) produced a negative ES of -0.4 (Pearson r).
Nine results in this evidence set report null or below-chance outcomes, and directional disagreement is pervasive across laboratories and designs. At least one pooled analysis shows high between-study heterogeneity (I² at or above 50%), meaning a single summary figure poorly represents the distribution of findings. Hit rates in individual studies, such as Kekecs (2023) at 0.4989 and Laythe (2022) at 0.2159, further illustrate how widely outcomes vary. Whether the positive signals reflect a genuine small effect, methodological variation, or publication-related factors remains an open and actively debated question in the literature.
Pooled meta-analytic effects
- Storm (2023), Journal of Scientific Exploration: ES 0.02 (z_over_sqrt_n) (k = 141)
- Rock (2023), International Journal of Transpersonal Studies: ES 0.39 (cohens_d)
- Milton (1999), British Journal of Psychology: ES -0.0046 (z_over_sqrt_n) (k = 8)
- Steinkamp (1998), The Journal of Parapsychology: ES 0.01 (z_over_sqrt_n) (k = 22)
The evidence
| Paper | Reported finding | Effect / significance | Basis |
|---|---|---|---|
| Laythe et al. (2024), Journal of Scientific Exploration [source] | Open ESP, whole sample. | p = .0058, hit rate 0.211 | N = 107 participants |
| Boscariol et al. (2024) [source] | Experimental group – Placebo condition. | ES 0.056, z = 2.85, p = .0047, hit rate 0.2228 | N = 2500 trials; 100 participants |
| Storm et al. (2023), Journal of Scientific Exploration [source] | Combined database 1987-2022 – homogeneous. | ES 0.02, z = 8.52, p < 1 × 10−16 | 141 studies |
| Kekecs et al. (2023), Royal Society Open Science [source] | Primary analysis — erotic trials. | hit rate 0.4989 | N = 37836 trials; 2115 participants |
| Rock et al. (2023), International Journal of Transpersonal Studies [source] | Forced choice clairvoyance-precognition normal state exceptional subjects: overall meta-analysis. | ES 0.39 | — |
| Laythe et al. (2022), Journal of Scientific Exploration [source] | Overall ESP hit rate. | hit rate 0.2159 | N = 44 participants |
| Radin (2019), Journal of Scientific Exploration [source] | Combined sequential hit rate hrseq. | z = 11.28, p = 1.7 × 10−29, hit rate 0.320503 | N = 114000000 trials; 200000 participants |
| Billows et al. (2015), Australian Journal of Parapsychology | Full sample ESP hit rate. | z = -0.35, p = .726, hit rate 0.1976 | N = 3725 trials; 149 participants |
| Schmidt et al. (2012), Zeitschrift fur Anomalistik / Journal of Anomalistics [source] | Q1 – Overall hit rate vs chance. | z = 1.35, p = .18, hit rate 0.114 | N = 880 trials; 22 participants |
| Ertel (2010), Journal of Scientific Exploration [source] | APRU replication – double hits. | ES 0.025, z = 2.99, p = .002, hit rate 0.1075 | k = 1 events/tests; N = 14400 trials; 40 participants |
| Rey et al. (2010), Zeitschrift fuer Anomalistik / Journal of Anomalistics [source] | H1 Telepathy condition. | p = .26, hit rate 0.2054 | N = 2400 trials; 96 participants |
| Ertel (2009), Zeitschrift fuer Anomalistik / Journal of Anomalistics [source] | GEMI ball test – 3 participants pooled, under control. | ES 0.247, z = 11.5, p = 1 × 10−30 | k = 3 events/tests; N = 2160 trials; 3 participants |
| Milton et al. (1999), British Journal of Psychology [source] | Overall cumulated mass-media ESP effect. | ES -0.0046, z = -1.6 | 8 studies; N = 1500000 trials; 86000 participants |
| Steinkamp et al. (1998), The Journal of Parapsychology [source] | Comparable studies sample – precognition mean ES. | ES 0.01 | 22 studies |
| Palmer (1994), Journal of the Society for Psychical Research [source] | Overall ESP scoring vs 50% chance. | p > .1, hit rate 0.4908 | N = 10500 trials; 103 participants |
| Vaughan et al. (1991), Subtle Energies & Energy Medicine Journal [source] | Combined 46 AC experiments – first-to-third series increase. | z = 1.98, p = .024 | k = 46; N = 21 participants |
What is unsettled
- Reported directions disagree across studies (some positive, some null or below-chance).
- High between-study heterogeneity (I² ≥ 50%) in 1 pooled result(s).
- 8 result(s) report a null or below-chance (negative) effect.
Source: ESP-Nexus structured study database, 16 studies. 16 born-digital figures; OCR-derived figures awaiting source-verification are excluded from this digest. Effect sizes are shown only where a standardized metric is recorded.