 A second type of publication bias has also played a substantial role in the reproducibility crisis, namely a bias towards “statistically significant” or “positive” results. Unlike the bias against replication studies, this is rarely an explicitly stated policy of a journal. Publication bias towards statistically significant findings has a long history, and was first documented in psychology by Sterling (1959). Developments in text mining techniques have led to more comprehensive estimates. For example, Fanelli’s work has demonstrated the extent of publication bias in various disciplines, and the proportions of statistically significant results given below are from his 2010a paper. He has also documented the increase of this bias over time (2012) and explored the causes of the bias, including the relationship between publication bias and a publish or perish research culture (2010b).