4. It does not account for Selection Bias. Just because some particular sample show a correlation does not mean the true distribution is correlated. This is alm

4. It does not account for Selection Bias. Just because some particular sample show a correlation does not mean the true distribution is correlated. This is almost certainly true if you look at lots (say 10+) relationships. It's just too easy to fool yourself. For every time someone claimed no causality there are dozens, perhaps hundreds, of cases of false claims of causality. There is a huge bias. The true test of causality is reproducible experiments. If X causes Y then making X happen should make Y much more likely. Unfortunately reality is not so easy to arrange.