When the Ebola virus was ravaging western Africa in 2015, a curious thing happened: Americans whose chances of being infected were effectively zero became terrified of the disease. What’s more, some of these people began to advocate xenophobic policies that medical experts said would only make the situation worse.

A pair of UC Santa Barbara researchers decided to look into this phenomenon, and what they found could help medical relief efforts in future outbreaks around the world. Heejung S. Kim and David K. Sherman, professors in the Department of Psychological and Brain Sciences, discovered that the more people felt vulnerable to Ebola the more xenophobic they became. Their degree of xenophobia, however, was directly influenced by how individualistic or collectivistic they were.