"The study of 261 senior professionals in the United States found that 21 per cent had clinically significant levels of psychopathic traits. The rate of psychopathy in the general population is about one in a hundred."

And I personally think if you examine ceos of highly successful companies, the ratio will be higher than 1 in 5.

Sure it's ONE study. But it actually makes sense. You don't get to the top in modern corporate world (especially hyper competitive one like the tech) without being slightly crazy.