Correlation Confusion

Correlation does not imply causation — the most repeated warning in statistics, and the most ignored. Ice cream sales and drowning deaths both rise in summer, but ice cream does not cause drowning. A hidden variable (hot weather) drives both in practice.

Spurious correlations are everywhere. The divorce rate in Maine once correlated almost perfectly with margarine consumption. With enough variables, you will always find patterns. Without a causal mechanism, a correlation is just a coincidence.