Participants in a study that explored this phenomenon were first exposed to either neutral cues or subtle disgust-inducing cues (such as diapers, anti-diarrhea medicine, and incontinence products), and then asked to flip a coin. The coin flip result would decide whether they would be part of a study that would make them eligible to earn some money. People exposed to the disgust inducing cues were likelier than those exposed to the neutral cues to falsely report a favorable coin flip result.
A number of other studies have also found that enhanced self-interest is associated with unethical behaviors. Just reminding people of their biological need to be protected seems to cause them to behave in ways that protect themselves, even at the cost of others.
Combine that with disgust:
https://www.psychologytoday.com/us/blog/parenting-neuroscience-perspective/202009/the-evolution-disgust-responses
Wonder if this is what they have been "studying" at gitmo this whole time? Remember seeing a pic with the surgical masks on the prisoners.