Proof Engine Verification: The correlation between human brain volume and intelligence is r = 0.4

Verdict: PARTIALLY VERIFIED - **SC1 (unconditional overall estimate) — FAILS:** Two independent large-scale meta-analyses, Pietschnig et al. (2015) and Nave et al. (2022), both report r = 0.24 for the unconditional brain volume–IQ correlation. The deviation from 0.40 is 0.16, well outside the ±0.05 tolerance. - **SC2 (conditional estimate: healthy adults, high-quality tests) — PASSES:** Wikipedia's Neuroscience and intelligence article (citing Gignac & Bates 2017, *Intelligence*) states r ≈ 0.40 when high-quality IQ tests