You are never going to be able to prove causality.

But this type of study can't prove causality.

But such population studies are subject to the criticism that statistical correlation does not prove causality.

We need to remember that correlation does not prove causality because of possible confounding factors.

Collins and colleagues concluded that the association does not prove causality, but is sufficient to warrant caution by parents of adolescents.

First, many of the pollutants were classified as probable carcinogens because data were not sufficient to prove causality in humans.

"We can never prove causality in social science," Mr. Zagorsky said.

Arguments against the use of Bradford Hill criteria as exclusive considerations in proving causality also exist.

Apart from some of the empirical problems mentioned earlier, a fundamental point is whether correlation, no matter how good it might be, proves causality.

But finding a correlation between certain attitudes and health outcomes doesn't, of course, prove causality.