Analysis of biased language in peer-reviewed scientific literature on genetically modified crops

Social, political, and economic forces may inadvertently influence the stance of scientific literature. Scientists strive for neutral language, but this may be challenging for controversial topics like genetically modified (GM) crops. We classified peer-reviewed journal articles and found that 40% had a positive or negative stance towards GM crops. Proportion of positive and negative stance varied with publication date, authors' country of origin, funding source, and type of genetic modification. Articles with a negative stance were more common at the beginning of the millennium. Authors from China had the highest positive:negative ratio (8:1), followed by authors from the USA (12:5) and the EU (5:7). Positive stance articles were six times more likely to be funded by private sources compared to those with a neutral or negative stance. Articles about glyphosate were more likely to be negative compared to articles about Bacillus thuringiensis. Linguistic features of articles with positive and negative stances were used to train a random forest classifier that predicts stance significantly better than random chance. This suggests the possibility of an automated tool to screen manuscripts for unintended biased language prior to publication.