(This is a repost of another thread that was getting tons of spam comments)

A common anecdote that probably stems from a research finding is that keyboards have more germs on them than toilet seats. While I can definitely see this, that got me wondering whether certain parts of a keyboard have a greater number than others. Certain keys are touched more, after all.

Intuitively, you’d expect the proportions to match the letter distribution of the typist’s native language, with some other keys, such as shift, enter, and the space bar having very high frequencies as well. Weird, mostly useless keys like Scroll Lock would probably have next to nothing.

This goes for piano keys too. People probably touch more keys on the right hand of the keyboard, as that’s where the melody usually is – so it stands to reason that the right side of a piano keyboard would be dirtier than the left.