I don't know if there is any principle like this, if not I will coin it here...

xlayn principle:

Any organism conformed of several type of different units with one of them capable of political capabilities will transform itself to have a head (read it as president, board of directors, human head as brain, stakeholders, etc) and will transform itself such as that the head become the goal at the expense of the rest of the organism.

e.g.

  -head decides to overeat to enjoy the related pleasure
   at the expense of other organs in the body
  -company shift objective to make money to the board of
   directors at the expense of the employees
  -humans as the "reason de etre" of the world destroys
   every other specie for the sake of their benefit...
  -this article...
  -corrupt governments

edit: Please let me know if a principle that states this exists.