All humans are 99.9 per cent identical and, of that tiny 0.1 per cent difference, 94 per cent of the variation is among individuals from the same populations and only six per cent between individuals from different populations.NA survey finds all humans are 99.9pc the same. By Roger Highfield, Science Editor. 12:01AM GMT 20 Dec 2002. Whether you hail from Surbiton, Ulan Bator or Nairobi, your genetic make-up is strikingly similar to that of every other person on Earth, an analysis concludes today.