Content of biased words in low versus high impact journals. The data are normalized by dividing the total word score obtained for an article by the total number of words contained in that same article. The median, 25th, 75th, percentiles are shown. The data show that there was a significant increase in the use of highly biased words over the past 20 years in high impact journals but not in low impact journals. Statistical significance was assessed by Student T-test and corrected for multiple comparisons.