The medical literature is riddled with biases, mostly cleverly concealed. But here’s a great new name for a bias that has hitherto gone incognito.

“White Hat bias” arises when authors misrepresent the evidence so that it favours the fashionable view of the moment. Its name comes from old-style Westerns in which the hero always wore a white hat, the baddie a black one. In the days of black-and-white, it made the plot easier to follow.
 
Mark Cope and David Allison of the University of Alabama have put White Hat bias on the map with a study in International Journal of Obesity that traces how righteous zeal can put a definite swerve on reported results. They looked at two studies, one that reported the effect of sugar-sweetened drinks and another, by WHO, on the effects of breast-feeding, and examinded how these results were cited and reported by other scientists.
 
They found that less than a third of papers that cited the sugar study accurately reported the overall findings and two thirds exaggerated evidence that cutting sugary drinks reduced weight. In the breastfeeding studies, authors selectively quoted evidence that breastfeeding reduced the risk of obesity. Studies that contradicted the conventional belief that sugar wears a black hat, and breast feeding a white one, were much less likely to be published.
 
The bias appeared in academic studies, not – as you might expect – in those funded by industry. Mixing their metaphors with a cocktail shaker, the authors conclude: “White Hat bias is s slippery slope that science and medicine need to resist.”