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.
Roberto Pavani (Sat,) studied this question.