Psychopaths
are known to be wily and manipulative, but even so, they unconsciously betray
themselves, according to scientists who have looked for patterns in convicted
murderers' speech as they described their crimes.
The
researchers interviewed 52 convicted murderers, 14 of them ranked as
psychopaths according to the Psychopathy Checklist-Revised, a 20-item
assessment, and asked them to describe their crimes in detail. Using computer
programs to analyze what the men said, the researchers found that those with
psychopathic scores showed a lack of emotion, spoke in terms of
cause-and-effect when describing their crimes, and focused their attention on
basic needs, such as food, drink and money.
While
we all have conscious control over some words we use, particularly nouns and
verbs, this is not the case for the majority of the words we use, including
little, functional words like "to" and "the" or the tense
we use for our verbs, according to Jeffrey Hancock, the lead researcher and an
associate professor in communications at Cornell University, who discussed the
work on Monday (Oct. 17) in Midtown Manhattan at Cornell's ILR Conference
Center.
"The
beautiful thing about them is they are unconsciously produced," Hancock
said.
These
unconscious actions can reveal the psychological dynamics in a speaker's mind
even though he or she is unaware of it, Hancock said.
What
it means to be a psychopath
Psychopaths
make up about 1 percent of the general population and as much as 25 percent of male offenders in federal
correctional settings, according to the researchers. Psychopaths are typically
profoundly selfish and lack emotion. "In lay terms, psychopaths seem to
have little or no 'conscience,'" write the researchers in a study
published online in the journal Legal and Criminological Psychology.
Psychopaths
are also known for being cunning and manipulative, and they make for perilous
interview subjects, according to Michael Woodworth, one of the authors and a
psychologist who studies psychopathy at the University of British Columbia, who
joined the discussion by phone.
"It
is unbelievable," Woodworth said. "You can spend two or three hours
and come out feeling like you are hypnotized."
While
there are reasons to suspect that psychopaths' speech patterns might have
distinctive characteristics, there has been little study of it, the team
writes.
How
words give them away
To
examine the emotional content of the murderers' speech, Hancock and his
colleagues looked at a number of factors, including how frequently they
described their crimes using the past tense. The use of the past tense can be
an indicator of psychological detachment, and the researchers found that the
psychopaths used it more than the present tense when compared with the
nonpsychopaths. They also found more dysfluencies — the "uhs" and
"ums" that interrupt speech — among psychopaths. Nearly universal in speech,
dysfluencies indicate that the speaker needs some time to think about what they
are saying.
With
regard to psychopaths, "We think the 'uhs' and 'ums' are about putting the
mask of sanity on," Hancock told LiveScience.
Psychopaths
appear to view the world and others instrumentally, as theirs for the taking,
the team, which also included Stephen Porter from the University of British
Columbia, wrote.
As
they expected, the psychopaths' language contained more words known as
subordinating conjunctions. These words, including "because" and
"so that," are associated with cause-and-effect statements.
"This
pattern suggested that psychopaths were more likely to view the crime as the
logical outcome of a plan (something that 'had' to be done to achieve a goal),"
the authors write.
And
finally, while most of us respond to higher-level needs, such as family, religion or
spirituality, and self-esteem, psychopaths remain occupied with those needs
associated with a more basic existence.
Their
analysis revealed that psychopaths used about twice as many words related to
basic physiological needs and self-preservation, including eating, drinking and
monetary resources than the nonpsychopaths, they write.
By
comparison, the nonpsychopathic murderers talked more about spirituality and
religion and family, reflecting what nonpsychopathic people would think about
when they just committed a murder, Hancock said.
The
researchers are interested in analyzing what people write on Facebook or in
other social media, since our unconscious mind also holds sway over what we
write. By analyzing stories written by students from Cornell and the University
of British Columbia, and looking at how the text people generate using social
media relates to scores on the Self-Report Psychopathy scale. Unlike the
checklist, which is based on an extensive review of the case file and an
interview, the self report is completed by the person in question.
This
sort of tool could be very useful for law enforcement investigations, such as
in the case of the Long Island serial killer,
who is being sought for the murders of at least four prostitutes and possibly
others, since this killer used the online classified site Craigslist to contact
victims, according to Hancock.
Text
analysis software could be used to conduct a "first pass," focusing
the work for human investigators, he said. "A lot of time analysts tell
you they feel they are drinking from a fire hose."
Knowing
a suspect is a psychopath can affect how law enforcement conducts
investigations and interrogations, Hancock said.
