Relax, Dickie, it's nothing personal

Scientists say urge to punish is instinctual.

“The urge to take revenge or punish cheaters,” said Michael McCullough, a professor of psychology at the University of Miami and author of the book “Beyond Revenge: The Evolution of the Forgiveness Instinct,” “is not a disease or toxin or sign that something has gone wrong. From the point of view of evolution, it’s not a problem but a solution.
The downside of these instincts, Dr. McCullough added, “is that they often promote behavior that turns out to be spiteful in the long run.”

Darn it, there's always a downside!