[bjourne]

No, people are terrible at detecting patterns. It took medicine a few thousand years before Semmelweis came along and detected a correlation between hand-washing and childbed fever. But also there is no pattern to detect, eating pork just isn't unhealthy (American diet notwithstanding).

[arthens]

I'm not weighting in on the ability of people to detect patterns, but hand washing is a bad example.

Detecting a pattern between 2 things that did happened (everyone but Dave ate pork, and everyone but Dave got sick) is orders of magnitude easier than detecting a pattern between something that did happened (this patient got sick) and something that didn't (everyone washed their hands).