Placebo Effects: Psychologyâ€™s Fundamental Flaw? Why active controls are not enough
A new paper published in Perspectives in Psychological Science (open access) suggests there is â€œa fundamental design flaw that potentially undermines any causal inferenceâ€ in much psychology research.
Way back in the 1950â€™s a phenomenon called the Hawthorne effect (AKA the observer effect) was observed, an experiment to discover whether workers in the Hawthorne Works plant were more productive under increased lighting, found that productivity increased whenever the workers were being observed, regardless of the variable in question. The effect is a common cause of the placebo effect, which in most aspects of medicine is effectively handled by the gold standard of double blind randomised controlled trials (RCTâ€™s). Unfortunately this is not always possible in psychology, not least because it is often impossible to blind an individual to the intervention, let alone the experimenter.