A remark on the quantum correlation function and the Pearson coefficient of classical projections

An elementary identity is noted: the quantum correlation E(a,b) = −cos(a−b) predicted for a singlet state is numerically identical to the Pearson correlation coefficient of two classical cosine projections sharing a common hidden angle. The question is posed whether this coincidence has structural significance. The connection to Fine's theorem (1982) on joint distributions and CHSH inequalities is discussed.