How do we measure psychopathy and how is it related to violence? According to Camp and colleagues (2013), a widely known test called the Psychopathy Checklist-Revised (PCL-R) is applied in justice contexts.
Psychologists often use this test to assess the likelihood that an offender commits violence. Typically, it is believed that past behaviors are the best predictors of future similar behaviors. According to the PCL-R, psychopaths are:
“Intraspecies predators who use charm, manipulation, intimidation, and violence to control others and to satisfy their selfish needs.”
However, there is only little evidence to suggest that people with high PCL-R scores commit violence. Therefore, it is more likely that specific features of psychopathy are linked to specific types of violence.
There are probably two types of violence: reactive and instrumental violence:
“… Reactive violence is motivated by the desire to harm someone and typically occurs in response to frustration, a threat to safety, or other perceived provocation, whereas instrumental violence is committed to achieve a secondary reward (e.g., money, drugs, or power) by harming someone.” (p. 468).
A study by Camp and colleagues (2013) found that impulsive and antisocial features of psychopathy are directly related to lifetime patterns of violence of instrumental qualities, i.e. goal directedness.
The study also highlights that instrumental aggression does not necessarily reflect lack of emotional depth (empathy), as one might assume.
Another important point to make is that instrumental violence is not emblematic of psychopathy, it is just closely related to impulsive and antisocial features of psychopathy.
The study (Camp et al., 2013) emphasizes that disinhibition (impulsivity), heightened negative affectivity, and a tendency toward externalizing behavior are personality features that strongly predict lifetime patterns of violence.
On the contrary, interpersonal and affective features of psychopathy are more related to reactive violence, i.e. violence that arises out of fear and provocation, and these features do not predict lifetime patterns of violence.
Impulsivity and antisocial behavior have been associated with instrumental violence, which means that these features predict instrumental violence more than mere outbursts of anger. Broad traits like impulsivity, however, are not specific to psychopathy.
The study also challenges the common view that psychopaths are driven toward violence for material gain, since interpersonal and affective features of psychopathy are found to be related to reactive violence.
So, why do people commit instrumental violence? According to the strain theory, social disadvantage may lead to instrumental violence (criminal behavior):
“Many people … are prevented from getting the money they need through legal channels, such as work … As a consequence, such people experience strain, and they may attempt to get money through illegal channels —such as theft, selling drugs, and prostitution.“ (p. 477).
On the basis of this research, acts of violence are not just acts of violence. There are two types of violence: reactive and instrumental violence, and people, including psychopaths, commit violence for different reasons.