There is a misguided assumption in a lot of media reporting on research that correlation equals causation. Correlation is a statistical relationship between two variables – for example, amounts of social service funding and crime rates – that assumes that one variable has some degree of dependence on the other.  In other words, if one variable changes, there should be a change in the other variable if the two are correlated.

There is a problem with this assumption, however – (more…)