sociopaths are around 5% and psycopaths are about 1% of the general population.

The cluster B personality disorders are the most difficult because the psycopaths in particular are non treatable and they are incredibly destructive.

Sadly the terms sociopath and psycopath are used almost interchangeably and worse still they are often used by normal people to describe others who are less than normal (but not necessarily evil or bad)

Fortunately science seems to be cracking the code for personality disorders with researchers isolating particular genes which seem to predispose individuals to this condition. Also medical imaging is revealing differences between regular people's brains and those who are personality disordered.

While it won't stop "bad behaviour", in the broader community - it will be a HUGE leap forward when we will be able to unmask and weed out the truly evil from society in general, before they have a chance to be.