In the May 2010 Harvard Business Review Magazine, researcher Dana Carney was called upon to explain her finding that "A sense of power buffers individuals from the stress of lying and increases their ability to deceive others."

Carney's description of her research and her findings is by her own account "troubling."

We measured subjects on five variables that indicate lying—involuntary shoulder shrugs, accelerated speech, the level of the stress hormone cortisol in their saliva, cognitive impairment, and emotional distress. Only the low-power liars could be “seen” as lying; the readings for the liars with power were essentially the same as those for truth tellers on all five variables. People with power lied more easily and effectively, which is troubling. Just as kids don’t touch a stove once they learn it burns them, people don’t like to lie because it hurts them emotionally and physiologically. These data suggest that powerful individuals—CEOs, portfolio managers, politicians, elite athletes—don’t get burned when they touch the figurative stove. They seem to be more physiologically “prepared” to lie, which could lead to their lying more often.." 
http://hbr.org/2010/05/defend-your-research-powerful-people-are-better-liars/ar/1


Carney's analogy of getting burned by a stove is a good one.  The stove is an external influence and can effectively modify behavior.  For those in power, there is no external force.  The force for keeping behavior in check must be internal.  In the interest of preservation of the power equation, those who are in power may reject personal accountability and turn off that internal behavior check.  The powerless are accountable to external forces.  The powerful are accountable to themselves.  If they abdicate their personal accountability driven by the self-interested motivation of preserving power, they are accountable to nothing.  

Isn't it interesting that it is a sense of power that "buffers individuals from the stress of lying and increases their ability to deceive others" and not a sense of Leadership. 

What do you value beyond yourself?  What are the values that you hold dear no matter what the situation and no matter how the outcome will affect you personally?  These are questions that a leader of character challenges him/herself with each day.  They may be in positions of extreme power and influence over others, but because leaders of character have identified and revisit the values that are larger than their own self-interest, they will remain accountable.