Science is currently said to be suffering a “replicability crisis”. Over the last few years a worrying number of widely accepted findings in psychology, medicine and other disciplines have failed to be confirmed by repetitions of the original experiments. Well-known psychological results that have proved hard to reproduce include the claim that new-born babies imitate their mothers’ facial expressions and that will power is a limited resource that becomes depleted through use. In medicine, the drug companies Bayer and Amgen, frustrated by the slow progress of drug development, discovered that more than three-quarters of the basic science studies they were relying on didn’t stand up when repeated. When the journal Naturepolled 1,500 scientists in 2016, 70 per cent said they had failed to reproduce another scientist’s results.
This crisis of reproducibility has occasioned much wringing of hands. The finger has been pointed at badly designed experiments, not to mention occasional mutterings about rigged data. But the only real surprise is that the problem has taken so long to emerge. The statistical establishment has been reluctant to concede the point, but failures of replication are nothing but the pigeons of significance testing coming home to roost.