The psychological characteristics of a lot of people who have it in them to climb to the top of a powerful organization, can be divided into (at least) two categories. First of all, they are talented people who have skills. Secondly, they have a personality (disorder) that fits into The Dark Triad: Narcissism, Machiavellianism, and Psychopathy.
There is in fact an evolutionary reason for this. If you are just as talented and skilled as your competitor, but you are better at manipulating and cheating because of your lower moral standards and your remorselessness, you have an advantage in the struggle to get to the top.
The kind of people who are actually best suited for positions of power (fair, empathetic and responsible people) often by their very nature have less desire for power and are less inclined to seek the spotlight.
So with a lot of people at the top having little or no sense of morality and a strong desire for power, we have a recipe for ruthless dictators in the form of emperors, kings, generals, presidents, CEO’s, et cetera, throughout human history.
These people have been responsible for the vast majority of unnecessary suffering that has occurred since the dawn of human civilization. So it is right to say that the personality disorders and Machiavellian traits of these people have been and still are the biggest problem in history.
Why is it obligatory for astronauts to undergo an extensive psychological assessment, but not for presidential candidates and CEO’s? Such a test would be at least as important for them.
In all (democratic) countries, rigorous psychological assessments (wherein special attention is paid to The Dark Triad) should, by law, be made mandatory for generals, presidents and CEO’s, before they can officially be installed into their position of power.
If such an assessment would then repeatedly yield significant results (especially in regard to Dark Triad traits), the candidate should be barred from being installed. That would relieve us (at least those of us living in democracies) from the biggest problem in history.