Mass hysteria in Le Roy, New York: How brain experts materialized truth and outscienced environmental inquiry

Teenage schoolgirls in Le Roy, New York, captured the attention of the U.S. public in 2011 and 2012 when they developed acute motor and vocal tics. Dramatic images of the girls' involuntary movements were briefly seen on national news and social media before clinical neurologists diagnosed the girls with "mass psychogenic illness" and required their retreat from media as part of the cure. Drawing from perspectives in medical and linguistic anthropology as well as the anthropology of expertise, we interrogate how this diagnosis, called "mass hysteria" in a previous generation of Freudian psychology, came to be favored over attribution to a potential environmental cause. Neurologists countered the evidential vagueness of environmental claims by suggesting that material proof of psychological origin could lie in fMRI data, contributing to a public narrative on female adolescent brains and rural U.S. communities that foreclosed environmental inquiry.