[Part I.]
Science is certainly far from infallible. That’s especially true of studies related to human beings, on whom any sort of research is notoriously difficult to perform and evaluate. The variables are myriad and uncontrollable, and ethics ordinarily prevents the sort of callous manipulation of subjects that would yield somewhat better results.
When evaluating a disease or syndrome, it helps if the vector of disease is singly determined. This is rarer than one thinks; even in diseases caused by microbes, for example, in which exposure to the microbe is a necessary cause of the illness, it is rarely a sufficient cause. There’s the poorly-understood problem of resistance—why do some people come down with the disease when exposed and others do not?
And even many problems that seem to have a strong genetic component (schizophrenia comes to mind) commonly have only about 50% concordance in identical twins, which indicates that some unknown environmental factor or factors must account for half the variance.
The scientific method was a triumph of human thought, but it took a while to develop because certain things about it are counterintuitive. It requires that we suspend judgment on the causes of a phenomenon even though we may think we can come to conclusions about it on the evidence of our eyes. But often the results run counter to what we would have predicted based on observations and/or intuition. And sometimes, of course, research yields incorrect or ambiguous results because of methodological or observational problems.
And so we come to the case of the autism epidemic. Continue reading →