Retrospective coverage for October 20, 2026. First published October 26, 2026 06:07 -07:00 (Pacific time). This is an AI-assisted brief compiled from linked public source records; the coverage date is not the publication date.
Japanese macaques that had lived through a viral outbreak were more reluctant to take food from a surface bearing a visual contamination cue, UC San Diego reported Oct. 20. The study suggests that exposure to illness in a social group can influence later behavior, even among animals that were not themselves infected. Research account.
Researchers studied 55 macaques at a Texas sanctuary. Three groups had experienced a 2020 outbreak of simian retrovirus type II; a fourth had not. Food was offered on clean wood or a surface covered with real feces sealed in epoxy, removing odor and infection risk from the comparison.
Animals from outbreak-exposed groups accepted food from the apparently contaminated surface in 47 percent of trials, compared with 79 percent among the unexposed animals. Previously infected and uninfected members of exposed groups behaved similarly.
The experiment measured food choices, not the animals' subjective emotions. Its findings concern learned caution and social experience; they do not establish that macaques experience human disgust. Methods and interpretation.