Well, the little buggers take a while to spread across a surface. They only move in terms of nanometers per second. Double to triple digits of nanometers per second, but still. They also tend to reproduce at a similar pace wherein even if they didn’t actively move themselves, the pressure from that would eventually cover a surface.

In other words, a few bacteria dropped on the back of hand can possibly end up having a colony on the palm of your hand in a few minutes.

However, since transferring from one surface to another is faster than that, well under a second, everything you touch is also going to have a colony soon after you touch it. Which isn’t necessarily bad since not all bacteria are pathogens to humans. But it very clearly shows why washing one’s hands thoroughly is a damn good idea.

So, even though the process can cause problems for hands, it’s still better than the problems of not washing thoroughly. Washing thoroughly includes both the palms and backs. If you’re washing often enough to cause skin problems, invest in good lotions and accept it as the price of not having pinkeye and diarrhea constantly.

People washing only the palms are going to eventually enjoy the pleasures of gastrointestinal upset and/or infected eyes, or respiratory infections. It might not be all the time, every time, but the chance of going through a year with poor hand washing in a medium to high risk environment without illness approaches zero. You might get lucky and it be nothing more than a cold, or something similarly easy to deal with.

But it might be MRSA.

Me? I’m playing the odds and following best practices.