Is it true that hurt people hurt people? Physical damage from war, a crime, an accident, a natural disaster, can cause bitterness. The resentment may be even greater if the harm was deliberate. This is physical abuse. Psychological abuse can also weaken a person’s ability to engage with the world, form friendships, find love, earn a living, and participate in the community. Some deprivation from the environment —famine, drought, pollution, poverty— can hinder fetal development. Genetics, too, can be a factor. Not everyone impaired in one or several of these ways will prove equally dangerous. I do not assume a perfectly fair criminal justice system, but incarceration provides a useful threshold of those most significantly affected. Those imprisoned for violent crimes constitute a much higher proportion than the general population of mentally ill people often called psychopaths (Dargis and Koenigs, 444a).

There is a danger in mentioning psychopathy. The concept may be overly broad, and the label “psychopath” can, perhaps wrongly, stigmatize a person for life. Still, we need a term to group the traits commonly found in violent criminals. Although the definition is still in flux, most psychologists agree that it has an inward and an outward aspect. Some psychopaths present a surly, emotionless withdrawal from others, a radical retreat into themselves. Others act outwardly through aggressive behavior. Their extreme goals overwhelm empathy or guilt and drive them with Machiavellian ruthlessness. (Marsh, et al. 2014, 36a, 37b-38a).

Psychologists have devised various ways to rate patients on the various symptoms of psychopathy to obtain a numerical score, indicating a person’s degree of illness (Bergstrøm, et al. 2018). “Psychopathic individuals” beyond a certain score, “commit a disproportionate amount of crime” (Dargis and Koenigs, 2018, 444a). An Italian study of 139 people “convicted of violent crimes (murder, rape, child sexual abuse, armed robbery, assault causing bodily harm)” found they scored high on a standard checklist for psychopathic traits. Prominent among those traits were two that show weak attachment to sexual partners. The convicts were promiscuous and had many marital relationships. Thus, they lacked affinity with people who might otherwise have aided them. Then, when the researchers interviewed the top ten scorers on the psychopathy checklist, all ten lacked fortifying adult relationships.

Seven of the same top ten “reported severe abuse during their childhood.” (Schimmenti, et al. 2014, 256.) That means they were deficient in attachments to those who, in more usual circumstances, would have raised them affectionately. Leaving aside purely genetic and environmental factors present before birth, inconsistent parent-child attachment or, worse, outright psychological or physical abuse during infancy or childhood may produce emotional conflicts that become “one pathway to psychopathy” (Dargis and Koenigs, 2018, 448b). There is, indeed, a clear “link between the exposure to abuse in childhood and subsequent criminal behaviors” (Schimmenti, et al. 2015, 340). Since those convicted of violent crime have, by definition, hurt people, and they frequently lacked emotional support from parents or parental figures in childhood and from mates in adulthood, it follows that HUP: hurt people hurt people.

Important questions nonetheless remain. What about abused or neglected children who do not become psychopaths or criminals? What about victims of crimes whose perpetrators were not psychopaths — who did not come from abusive backgrounds? Clearly, not all hurt people hurt people and not all hurt people were hurt by hurt people. These are important reservations to the principle of HUP.

There are, nonetheless, psychological traits that predispose some to harm others and these appear, though not as prominently, in adolescents. Weiler and Widom (1996), who studied adolescents, not convicted criminals, suggest that childhood neglect may provoke styles of coping that are not adaptive. Abuse may lead to abnormal brain chemistry that stimulates or worsens aggressive behavior. Removal to alternative child rearing arrangements such as foster parenting or institutionalization may turn out to be as traumatic as the original situation. Finally, the psychopath may have a genetic predisposition to seek external stimulation and sensations, to court danger, oblivious to the consequences. Once the pattern manifests itself, it is hard to break. “Some children disconnect their emotions as a coping response to repeated and significant trauma. Over time, this disconnection becomes permanent and the individuals present as if they were genetically predisposed psychopaths” (Stephen Porter, 1996, as cited by Campbell, 2004, 42). Even in this younger population, then, traumas such as psychological or physical abuse or being raised separately from one’s parents typify those who later score high in psychopathy, and these, in turn become a significant fraction of violent criminals. More concretely, and in conformity to HUP, higher scores on the psychopathy checklist (adjusted for adolescents) “were related to the experience of physical abuse and higher frequency of maltreatment by caregivers” (Campbell, 41). In short, childhood deprivation, abuse, or trauma can bend young people towards persistent antisocial or violent actions. Psychopathy can be a lifelong affliction (Weiler and Widom, 1996, 266). Its victims often victimize others.