Actually Keith, one person in every 25 does equal 4. If you add up 25 four times, that makes 100; and there will be 4 persons out of 100 that fit the bill as full-blown sociopaths (one person for each group of 25.) That makes 4. However, these are just the clear and unambivalent cases. The rest of the population has tendencies either toward neurosis, or toward character disorders such as sociopathology or narcisism. It would be interesting to get a graph, scatter plot, or some type of visual depiction of the dispersal of psychological problems across the population, but it might be too scarey to look at.