Skeptical Chronobiology Matrix

The Skeptical Chronobiology & Evidence Matrix

OpenAlex-indexed peer-reviewed research. Holding empirical science and biological hypotheses to rigorous evidentiary standards.

🔭OBSERVED

Sleep Architecture · 2013 GRADE B (Moderate)

Human sleep architecture and slow-wave EEG activity modulate in synchrony with lunar phase.

Cajochen, C., Altanay-Şahi̇n, S., Münch, M., et al. (2013). Evidence that the lunar cycle influences human sleep.

Sample Size (N):33

Study Design:Double-Blind In-Lab PSG

Measured Effect:Δ -20 min total sleep time; 30% reduction in delta power (NREM EEG)

In a strictly light-isolated sleep laboratory without time cues, subjects during the Full Moon took 5 minutes longer to fall asleep, slept 20 minutes less, and exhibited reduced subjective and objective sleep depth.

Mechanism: Endogenous circalunar oscillator coupled to human circadian pacemaker (BMAL1 / Cryptochrome gene network), independent of direct ocular light perception.

OpenAlex ID: W2087541604DOI: 10.1016/j.cub.2013.06.020

Sleep Architecture · 2021 GRADE A (Replicated)

Moonlight triggers nocturnal sleep delay and shorter sleep duration across diverse human societies.

Casiraghi, L., Spiousas, I., Dunster, G. P., et al. (2021). Moonstruck sleep: Synchronization of human sleep with the moon cycle under field conditions.

Sample Size (N):562

Study Design:Longitudinal Wrist Actigraphy

Measured Effect:Δ 46–58 minutes sleep delay; 25–40 minutes total sleep reduction in waxing phase

Continuous longitudinal sleep tracking across both indigenous Toba/Qom communities without electricity in Argentina and urban college students in Seattle showed identical synchronized sleep timing rhythms preceding the Full Moon.

Mechanism: Evolutionary adaptation utilizing natural nocturnal moonlight during waxing evenings to prolong wakefulness for foraging, socialization, and community defense.

OpenAlex ID: W3125217438DOI: 10.1126/sciadv.abe0465

Mood & Bipolar Cycling · 2018 GRADE C (Emerging)

Rapid-cycling bipolar mood switches synchronize with bi-monthly and multi-year lunar gravitational cycles.

Wehr, T. A. (2018). Bipolar mood cycles and lunar tidal cycles.

Sample Size (N):17

Study Design:Multi-Decade Patient Chart Cohort

Measured Effect:Phase-locking to 14.8-day spring-neap and 206-day perigee-syzygy beat frequencies

Long-term daily longitudinal mood switch records in rapid-cycling bipolar patients revealed discrete synchronizations with the 14.8-day fortnightly tidal cycle and the 206-day recurrence cycle of perigee-syzygy.

Mechanism: Gravimetric or geomagnetic field perturbations interacting with human circadian pacemaker neurons or internal electrolyte balance.

OpenAlex ID: W2582845667DOI: 10.1038/mp.2016.263

Marine Reproduction · 1986 GRADE A (Replicated)

Mass synchronous spawning in scleractinian reef corals is locked to nocturnal lunar irradiance cycles.

Babcock, R. C., Bull, G. D., Harrison, P. L., et al. (1986). Synchronous multispecific spawning on coral reefs: philosophy, evidence and mechanism.

Sample Size (N):105

Study Design:Ecological Marine Fieldwork

Measured Effect:Strict species-specific spawning within a 30-minute window 3–6 nights post-Full Moon

Over 100 species of reef-building corals simultaneously release gametes on the Great Barrier Reef during specific nights following the spring Full Moon.

Mechanism: Primitive photoreceptors (Cryptochrome CRY2) detect low-intensity blue/green moonlight spectra (480–520 nm), triggering gonadotropin surges.

OpenAlex ID: W2058287515DOI: 10.3354/meps029229

Emergency Medicine (Myth) · 1985 MYTH REFUTED

Full Moon increases psychiatric emergencies, homicides, traffic accidents, and crisis hotline calls.

Rotton, J., & Kelly, I. W. (1985). Much ado about the full moon: A meta-analysis of lunar-lunacy research.

Sample Size (N):187,612

Study Design:Epidemiological Registry Meta-Analysis

Measured Effect:r = 0.004 (Statistically indistinguishable from zero / null effect)

Comprehensive meta-analysis of 37 independent studies found no significant correlation between lunar phases and psychiatric hospital admissions, violent crimes, suicides, or emergency room trauma visits.

Mechanism: Psychological confirmation bias (selective recall of chaotic shifts during Full Moons while forgetting equally chaotic shifts during other phases) and the illusory correlation effect.

OpenAlex ID: W1993215904DOI: 10.1037/0033-2909.97.2.286

Financial Volatility · 2006 GRADE B (Moderate)

Global stock returns and financial asset volatility exhibit systematic cyclical variations with the lunar phase.

Yuan, K., Zheng, L., & Zhu, Q. (2006). Are investors moonstruck? Lunar phases and stock returns.

Sample Size (N):48

Study Design:Epidemiological Registry Meta-Analysis

Measured Effect:3–5% annualized higher returns during New Moon vs. Full Moon (p < 0.01)

Across 48 countries over a 30-year span, stock market returns were significantly higher during the 15 days around the New Moon than during the 15 days around the Full Moon, independent of calendar anomalies.

Mechanism: Behavioral finance: Subconscious mood/optimism shifts in investor sentiment induced by biological circadian/circalunar sleep modulation.

OpenAlex ID: W2058440810DOI: 10.1016/j.jempfin.2005.06.001