Examination of neurological disease research shows pervasive ‘significance bias’. A statistical analysis of more than 4,000 data sets from animal studies of neurological diseases has found that almost 40% of studies reported statistically significant results — nearly twice as many as would be expected on the basis of the number of animal subjects. The results suggest that the published work — some of which was used to justify human clinical trials — is biased towards reporting positive results. This bias could partly explain why a therapy that does well in preclinical studies so rarely predicts success in human patients, says...