The Irish Independent recently published an article purporting to show that acupuncture can aid pregnancy. To a skeptic, such news items also shows us why anecdote alone is often a bad indicator of extraordinary claims. Anecdote does not guard against the “Post Hoc ergo Propter Hoc” fallacy – the idea that if something was done before an event, then it somehow must have caused that event. This is irrational thinking on a par with rain dancing, throwing salt over your shoulder after spilling it and sacrificing a goat to prevent a volcanic eruption. As any scientist will tell you, determining causation is a tricky business. You need to eliminate other more likely competing causes, systematically reduce the effects of experimenter bias and have a big enough data set to see a universal effect. Failing this kind of experimentation you have two occurrences – the use of acupuncture and the onset of pregnancy – with the only connection being a strongly held belief that one event caused the other.
Brian Hughes over at The Science Bit has written a well argued piece on the Independent article where he looks at the evidence supporting acupuncture and increased fertility. It’s well worth a read.