The evidence for the functionality of these markers is often ambiguous (Cirulli & Goldstein, 2007), a factor that is not widely recognized by developmental psychologists. This is understandable as the methods of molecular biology go well beyond the expertise of most psychologists (and indeed, many geneticists!). Establishing functionality of genetic loci is a very challenging area, and one without strong consensus. The ambiguity of the evidence for functionality of the markers that are widely studied in the measured GxE literatures is rarely acknowledged or discussed.
