Maybe so, according to psychologists studying convicted murderers. In a new study of previously diagnosed psychopaths and non-psychopathic murderers, the researchers were able to discern who are psychopathic by analyzing their word choices:
Psychopaths were far more likely to say they committed the crime because of personal needs, like food and money, and they described their deeds in the past tense, suggesting it happened a long time ago and there was little that the perpetrator could do to prevent it. They seemed emotionally detached from the murder, and as might be expected, they showed no remorse. [...]
The non-psychopathic killers, by contrast, were far more likely to describe their past in terms that reflected social needs, like family, religion and spirituality.
"In the context of a committed murder, it is likely that the non-psychopaths were aware of and affected by the profound effects their crime would have had on their own families and the victim's family," the study says. No such concern was shown among the psychopaths.
The bottom line: "Psychopaths operate on a primitive but rational level," say the researchers (Link).
ABC News article on the story HERE... It kindof weirdly links to a piece on the investigation into the tragic double-homicide-suicide of pro-wrestler Chris Benoit, who killed his wife and kid and then himself in one terrible, terrible weekend.
Scientists have studied his brain, as well as that of many pro-football players, and have theorised that years of concussions and blows to the head compromise brain function -- effectively causing early dementia. In Benoit's case, it led to these terrible acts, which all agree were out of character. So, that's interesting and sad, but not exactly what the psycho study mentioned is about... but anyway, enjoy! .. that's really not the right word, is it...).
Ref: Hancock, J.T. Woodworth, M., & Porter, S. (In press, April 2011). Musings of Murderers: An examination of the linguistic production of psychopathic and non-psychopathic homicide offenders. Legal and Criminological Psychology.