Obvious third variable might be conscientiousness. People low on that personality trait may be generally more likely to pick their noses and catch COVID.

I’d be more concerned about hand washing. You’d be amazed at how many health care professionals don’t wash their hands properly.

The researchers said as the nose was a main route for coronavirus to get into the body, nose-picking may make infection easier by directly introducing virus particles on the hands into the nose.

Goddammit. I’m not going to live to see old age, am I?

I’ll file this under “Duh, no shit.”