This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: 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 that 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. "We can show now, in nonhuman primates, that this is the same for them," said Federico Rossano, an associate professor in the Department of Cognitive Science at UC San Diego's School of Social Sciences and senior author of the study.
"Even with no knowledge of how disease is transmitted, being exposed to others getting sick and dying changes the likelihood of engaging in behaviors that potentially could lead to some form of sickness." The research grew out of an unexpected event at a primate sanctuary in southern Texas, where the researchers conduct behavioral studies. The sanctuary is home to several groups of Japanese macaques descended from monkeys originally brought from Japan to Texas in 1972. Because the groups live in separate enclosures, the researchers had a rare opportunity to compare animals with similar backgrounds that had experienced very different social and disease environments.
In 2020, staff confirmed the presence of simian retrovirus Type II, which can cause an AIDS-like immunodeficiency, in some of the sanctuary's Japanese macaque groups. The virus was primarily transmitted through bites and scratches and caused severe illness and death in some animals. The sanctuary responded by separating groups and implementing strict testing and quarantine measures.
That created an unusual natural experiment. Three groups had experienced the outbreak. The researchers then tested 55 macaques to see how they responded to a choice between food placed on a clean wooden surface and food placed on a surface covered with real macaque feces sealed under a layer of clear epoxy, to preserve visual cues while removing the smell and any risk of infection.
Extract — continue reading at the source.
