Sociopaths.

antisocial personality disorder (ASPD or APD) is defined by the American Psychiatric Association's Diagnostic and Statistical Manual as "...a pervasive pattern of disregard for, and violation of, the rights of others that begins in childhood or early adolescence and continues into adulthood."
To be diagnosed, an individual must be age 18 or older, as well as have a documented history of a conduct disorder before the age of 15. People having antisocial personality disorder are sometimes referred to as "sociopaths" and "psychopaths."

Symptoms.
Characteristics of people with antisocial personality disorder may include:[2]
 Persistent lying or stealing
 Apparent lack of remorse[3] or empathy for others
 Cruelty to animals[4]
 Poor behavioral controls — expressions of irritability, annoyance, impatience, threats, aggression, and verbal abuse; inadequate control of anger and temper
 A history of childhood conduct disorder
 Recurring difficulties with the law
 Tendency to violate the boundaries and rights of others
 Substance abuse
 Aggressive, often violent behavior; prone to getting involved in fights
 Inability to tolerate boredom
 Disregard for safety

Psycopath
Psychopathy is a personality disorder characterized by an abnormal lack of empathy combined with strongly amoral conduct, masked by an ability to appear outwardly normal. Neither psychopathy, nor the similar concept of sociopathy, are nowadays defined in international diagnostic manuals, which instead describe a category of antisocial/dissocial personality disorder. However, researcher Robert Hare, whose Hare Psychopathy Checklist is widely used, describes psychopaths as "intraspecies predators".[3] Also R.I. Simon uses the word predator to describe psychopaths. Elsewhere Hare and others write that psychopaths "use charisma, manipulation, intimidation, sexual intercourse and violence"[5][6][7][verification needed] to control others and to satisfy their own needs. Hare states that: "Lacking in conscience and empathy, they take what they want and do as they please, violating social norms and expectations without guilt or remorse".[8] He previously stated that: "What is missing, in other words, are the very qualities that allow a human being to live in social harmony
causes
One twin study suggests that psychopathy has a strong genetic component. The study demonstrates that children with anti-social behavior can be classified into two groups: those who were alsocallous acquired their behavior by genetic influences, and those who were not callous

acquired it from their environment.[24] "The amygdala is crucial for stimulus–reinforcement learning and responding to emotional expressions, particularly fearful expressions that, as reinforcers, are important initiators of stimulus–reinforcement learning. Moreover, the amygdala is involved in the formation of both stimulus–punishment and stimulus–reward associations. Individuals with psychopathy show impairment in stimulus–reinforcement learning (whether punishment or reward based)and responding to fearful and sad expressions. It is argued that this impairment drives much of the syndrome of psychopathy"(Blair, 2008).


Examples of that:
The criminal brain has always held a fascination for James Fallon. For nearly 20 years, the neuroscientist at the University of California-Irvine has studied the brains of psychopaths. He studies the biological basis for behavior, and one of his specialties is to try to figure out how a killer's brain differs from yours and mine.
About four years ago, Fallon made a startling discovery. It happened during a conversation with his then 88-year-old mother, Jenny, at a family barbecue.
"I said, 'Jim, why don't you find out about your father's relatives?' " Jenny Fallon recalls. "I think there were some cuckoos back there."
Fallon investigated.
"There's a whole lineage of very violent people — killers," he says.
One of his direct great-grandfathers, Thomas Cornell, was hanged in 1667 for murdering his mother. That line of Cornells produced seven other alleged murderers, including Lizzy Borden. "Cousin Lizzy," as Fallon wryly calls her, was accused (and controversially acquitted) of killing her father and stepmother with an ax in Fall River, Mass., in 1882.
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A little spooked by his ancestry, Fallon set out to see whether anyone in his family possesses the brain of a serial killer. Because he has studied the brains of dozens of psychopaths, he knew precisely what to look for. To demonstrate, he opened his laptop and called up an image of a brain on his computer screen.
"Here is a brain that's not normal," he says. There are patches of yellow and red. Then he points to another section of the brain, in the front part of the brain, just behind the eyes.
"Look at that — there's almost nothing here," Fallon says.
This is the orbital cortex, the area that Fallon and other scientists believe is involved with ethical behavior, moral decision-making and impulse control.
"People with low activity [in the orbital cortex] are either free-wheeling types or sociopaths," he says.


Some books talking about that:
Featured Manuals and Books

Psychology of Criminal Investigations: The Search for the Truth
edited by Michel St-Yves and Michel Tanguay
Includes a chapter by Dr. M. Logan & Dr. R. D. Hare entitled "Criminal psychopathy: An introduction for police".

International Handbook on Psychopathic Disorders and the Law
edited by Alan R. Felthous and Henning Saß, 2008
Winner of the 2009 Guttmacher Award







Lucas pihedradita

Simon mosqura

Juan David Moncada