Nah. People are just more adaptable to their circumstances than you think.

Something I think about from time to time is sacking during war, where soldiers are allowed to do as they please with a conquered civilian population. If I applied your same reasoning, I'd have to conclude that on average there's a great number of people who are not committing atrocities just because of the fear of repercussions. What I think happens is that getting desensitized to violence and being constantly made to make violent decisions makes anymore more likely to commit a violent act that they never would have otherwise. It doesn't need a special kind of brain, it just needs special circumstances.

Same for anyone in a position of power, except it's shamelessly lying and making decisions that affect hundreds or thousands of people, instead of direct violence.