One of the
questions I commonly receive about MRI research on pedophilia is: How
do we know what causes what? Comparing the brain scans of
pedophiles with non-pedophiles gives us a correlation, and correlation does not
necessarily mean causation.
It is true
that correlation does not equal causation, but that does not mean we are
powerless about it either. To understand how to attack this kind of
problem, we need to recall a few important (but pretty rarely discussed) principles
of science:
First, no
scientific statement will ever be 100% proven. There is no such thing as
a perfect study. That is, anyone will always be free to reject any
result, claiming the lack of perfection of whatever study(ies).
Next is
parsimony: Because we cannot prove anything, the best science can do is
explicate each of the possibilities and to pick the best answer available. In
science, the best means the most parsimonious; that
is, the simplest explanation for the data.