What's your biometric ratio, Tunesmith? You seem to be having some problem thinking this out.

All sorts of things affect a person's ability to think clearly. The biggest problem isn't their weight, alcohol, drugs, tiredness etc.etc., all though all these can get in the way if they aren't careful. The main thing that impedes clear thinking is history- the personal and cultural history that puts no-go areas in people's minds. And it's invisible to speak-your-weight machines, scanners, cardiac monitors, breathalysers, even lie detectors (because they AREN'T lying).