A lot of people kill other people. But not all of those murderers are psychopaths. One interesting way to understand the difference between psychopathic and non-psychopathic murderers is through their differing uses of language.

In February of 2013, researchers from Cornell University and the University of British Columbia analyzed the speech patterns of 14 psychopathic murders and 38 non-psychopathic murderers when they were talking about their crime. Keep in mind, all of the people they interviewed had been convicted of some type of homicide crime.

What the researchers found is interesting: Psychopaths used more language that indicated a cause-and-effect thinking style than the non-psychopaths. For example, a psychopath might say, "I hit her because she mouthed off to me," as opposed to, "She was mouthing off and then I hit her." Psychopaths also focused more of their crime speech on "material needs" like "food, drink, [and] money." They spent less time talking about social engagement, family, and religion. They also said "uh" and "um" more, and they tended to talk more in the past tense than the non-psychopaths.

This was obviously just one study with a limited number of participants. But, it helps to highlight what we already know about people with psychopathic tendencies: they tend to have problems relating to other people, they think in a rational manner, they feel justified in their actions, and they are more focused on their own material needs than they are on emotional and societal needs.

Which reminds me, I wrote a book about psychopaths. You can get to it here.

reference:
Hancock, J. T., Woodworth, M. T., & Porter, S. (2013). Hungry like the wolf: A word-pattern analysis of the language of psychopaths.Legal and Criminological Psychology, 18(1), 102-114.