Like Humans, Some Primates Become Cautious of Germs in the Wake of a Viral Outbreak

In the early days of the COVID-19 pandemic, many households wiped down groceries with disinfectant before putting them away. Hand sanitizer was in short supply. With little information on how the virus spread – people became more cautious of germs from other people. A new University of California San Diego study suggests that humans may not be alone in changing behavior after experiencing a disease threat.

Researchers found that macaque monkeys who had lived through a deadly disease outbreak became significantly more cautious about food that appeared contaminated, even though they did not know how the disease had spread. The findings suggest that pathogen-avoidance behavior can be shaped by experience, offering clues about the evolutionary roots of disgust.

The study , published in Royal Society Open Science, provides new insight into what scientists call the "behavioral immune system" — a collection of behaviors that help animals avoid infection before the body's biological immune system ever has to respond.