Psychopathy, the mental illness that produces serial and mass killers, like Ted Bundy (above) and Eric Harris (of Columbine, below), is really bizarre. It's imperfectly understood but what is known about it is terrifying.
Psychopaths have no capacity -- whatsoever -- for empathy. It's not a psychological defect or moral failing but seems to involve the configuration of the brain. The results of brain scans of psychopaths undergoing tests for empathy are utterly anomalous -- many animals have more capacity for empathy than human psychopaths.

The condition seems to be congenital, though there is some evidence that early childhood development can affect whether or not a psychopath becomes violent. Only a small percentage of psychopaths do become violent. The rest usually become hustlers or con-men of one sort or another. Psychopaths are almost always well-integrated socially, preternaturally adept at learning and mimicking the behaviors associated with empathy and other normal human emotions.

There is no cure for psychopathy, and it requires highly specialized tests to identify it. The illness actually grows worse with psychiatric therapy, unless the therapist has diagnosed it in advance. In all other cases the psychopath uses the therapy as an advanced course in determining what behavior the therapist is seeking to encourage and leaning to feign it. Eric Harris was undergoing court-ordered therapy -- the result of being arrested for a petty crime -- shortly before he committed the massacre at Columbine (seen in progress below) and his therapist thought he was making extraordinary progress. He didn't have a clue, not even the hint of a clue, as to Harris's actual mental state.
Harris's condition was diagnosed only after the fact through the extensive diaries he kept, which manifested all the recognized symptoms of psychopathy -- including his delight at fooling his therapist. (Dylan Klebold, Harris's partner in the Columbine killings, was a suicidal depressive -- a different kettle of fish entirely.)
Modern corporations, when they reach a certain size, also display the recognized symptoms of psychopathy. They operate on the principle of pure self-interest. Like psychopaths, they construct elaborate rationales for selfishness. They take as a given, for example, that any free market activity is morally justified, as leading to the greatest good for the greatest number. It follows from this that any action which benefits the shareholders, and by extension the executives and employees of the corporation, is morally sound. It is assumed that any "bad" actions in a market will be corrected by the market, which means that all "uncorrected" (i. e. profitable) actions are good by definition.

When Brooksley Born (above), the chairperson of a small regulatory commission in the Clinton administration, tried to warn Fed Chairman Alan Greenspan about the dangers of the unregulated market for over-the-counter derivatives -- the financial instruments which almost brought down the world economy last year -- he didn't want to hear about it. He was opposed even to regulations against outright fraud in this market, believing that the market itself would regulate fraud more efficiently than government ever could.
Greenspan and the Wall Street executives who think like him are not psychopaths, but they are intellectually invested in a theory of business and human behavior which has created a psychopathic system -- a system which sees selfishness as invariably productive and right and which simply denies any evidence to the contrary, as clinical psychopaths do. It is a form of magical thinking.

The proof that Greenspan is not a psychopath can be found in his admission this year that he was wrong in his assumptions about the behavior of markets and human beings acting through markets. A true psychopath is incapable of seeing any other point of view but his own and incapable of taking any responsibility at all for his actions.
But that's the problem with modern corporations of a certain size -- no individual is ultimately responsible for its actions. This is why non-psychopaths can commit psychopathic acts as agents of a corporation and feel no need to take responsibility for them. This is why the very executives who nearly brought the world to the brink of economic collapse still believe they are entitled to large compensation packages. They did nothing wrong -- it was the system which did it, and it's not their fault that the system is psychopathic.

In a way they have a point. Psychopaths are born psychopaths and can't be cured, just as large corporations are by nature psychopathic and can't be changed. This is not an argument, however, for letting psychopaths do anything they want to do, or for letting corporations do anything they want to do. Society is obliged to protect itself from psychopathic behavior in whatever form it takes -- even if those who engage in it aren't "guilty" or "responsible" in the usual senses of those words.
When Alan Greenspan told Brooksley Born that he didn't believe in regulating the markets for fraud, she should have felt empowered to make a citizen's arrest on the spot. It would have saved us all a lot of misery.
[I am indebted to Dave Cullen's extraordinary book Columbine for its fascinating summary of the current state of knowledge about psychopathy.]