This is interesting...

     Leaders lose mental capacities, most notably for reading other people, that were essential to their rise to power. That explains a lot of what we see happening in politics. The generation that once declared not to trust anyone over 30 now appears to trust few under 70. 
     In the U.S. government the average age of a congressional representative is 59, with leaders in their 70s and 80s and the average age of congressional representatives has been increasing since 1981 and today, typically, congressional representatives are 20 years older than their constituents. The highest levels of American politics bear an uncomfortable resemblance to a gerontocracy, a state, society, or group governed by old people and top positions are held more and more by people in their 70s or above. 
     Historian Henry Adams ((February 16, 1838 – March 27, 1918), an American historian and member of the Adams political family, described power as “a sort of tumor that ends by killing the victim’s sympathies.” Perhaps he was more right than we know. 
      Dacher Keltner, a psychology professor at UC Berkeley, studied subjects under the influence of power and found in studies spanning two decades, acted as if they had suffered a traumatic brain injury by becoming more impulsive, less risk-aware and less adept at seeing things from other people’s point of view. 
     Also, Sukhvinder Obhi, a neuroscientist at McMaster University in Ontario, recently described something similar. Obhi studies brains and when he put the heads of the powerful and the not-so-powerful under a transcranial-magnetic-stimulation machine, he found that power impairs a specific neural process called mirroring. His conclusion was that once a person has power, they lose some of the capacities they needed to gain it in the first place. 
     In a 2009 article published in The Brain, he and co-author Jonathan Davidson termed it the Hubris syndrome, defined as “a disorder of the possession of power, particularly power which has been associated with overwhelming success, held for a period of years and with minimal constraint on the leader.” 
     There’s also an effect on their followers. People tend to mimic the expressions and body language of their superiors. And at the same time, the powerful stop mimicking others which is called empathy deficit. 
     Something called mirroring which is a subtler kind of mimicry that goes on entirely within a person mind. When we watch someone perform an action, the part of the brain we would use to do that same thing lights up in sympathetic response. These changes are sometimes harmful. 
     Susan Fiske, a Princeton psychology professor, has argued that power lessens the need for a nuanced read of people, since it gives command of resources that once had to be cajoled from others. But, many leaders cross the line into folly. Less able to make out people’s traits, they rely on stereotype and the less they’re able to see.