Want to Boost Test Scores? Stop Misinterpreting Science.

From the  Education Week blog “Inside School Research” on May 25th, 2010 – Want to Boost Test Scores? Try Eating Dirt



This blog post (sponsored by a leading periodical in K-12 education) attempts to summarize the findings of this study, which found that the ingestion of a common soil bacterium,  Mycobacterium vaccae,  temporarily improved the anxiety levels and maze navigation abilities of a small group of mice. The blog post suggests that school gardening projects may produce a similar effect in small children.


The study in question examined both mice that had been injected with dead  Mycobacterium, and mice who had ingested live  Mycobacterium.  Each group of mice experienced some effect, which suggests that the compound or compounds responsible for producing the anxiety-reducing and learning-enhancing effects in mice may be a passive component of the bacterial cell wall, rather than an active mechanism that only functions in live microbes.

Critical Analysis:

This blog post has an extremely misleading title, and the text of the post contains major misinterpretations of the scientific study in question. Though the author attempts to say that the study doesn’t mean that children who eat dirt are smarter, it does imply throughout that consuming certain bacteria can change the base level intelligence of a child.  Clearly, this is an absurd claim, and a misinterpretation of the research. Not only is generalizing small animal studies to humans thoroughly unreasonable, it is also entirely possible that the potential reduction in anxiety experienced by the mice is what contributed to their improved maze navigation, and any anxiety-reducing agent would have had a similar effect.

In a world where a 10 year old’s test scores can determine a teacher’s income, we simply cannot justify misusing microbiology to tell  tired educators that the solution to low test scores is to make students play in the school garden.


How can we more effectively communicate the implications of our research to both educators and the public at large?