Mechanisms in the Association Between Abuse and Violence: Trauma and Dissociation
Abuse may cause violence because it causes trauma. Trauma has been mentioned in the etiology of delinquency at least since the 1940s (Marohn, 1974) and has been associated with aggression even in college samples (e.g., Scarpa, 2001). Trauma can occur as a response to exposure to spousal violence, neighborhood violence or to child abuse victimization. In turn, trauma has an array of insidious outcomes. Some authors link behavioral problems to a path from extreme fear, for example, to overwhelming negative emotion and cognition, and symptoms of posttraumatic stress disorder (PTSD). Trauma can have long-term effects in part by engendering alterations in brain chemistry which are thought to affect social interactions and academic performance (e.g., Bailey, 2006): “In some cases trauma may be seen as a significant aetiological [sic] factor for violent behaviour [sic] due to its adverse effects on psychological functioning, academic performance and normal parent-child relationships” (p. 29).
Traumatic abuse is often found in the childhood histories of serious offenders. Some authors have stated that “most” homicide offenders have suffered severe abuse as a child (e.g., Kamphuis & Emmelkamp, 2005). Research on female offenders, in particular, has emphasized this line of research. Brown (2006) argues that abuse and trauma are “ubiquitous” in the lives of incarcerated women whose lives have been characterized by chaos, loss, involvement in violent relationships, and drug use. Ryder (2003) interviewed female offenders and chronicled their traumatic histories: witnessing their mothers having vicious fights with their partners, being threatened with guns, witnessing the abuse of other children, being beaten with hangers being held by the neck, and being hit with a baseball bat. One subject reported having a glass broken on her leg; another reported being stabbed by her own mother, and another witnessed someone pushing a relative off a building. The list of such events goes on and on, and this sample was quite small. Eighty-eight percent of Ryder’s sample had experienced the death of a loved one, 75% reported being kicked, bit, hit, burned, or scalded by a family member; 74% had witnessed a stabbing or shooting outside the home. Neglect and disruptions in relations with parents were also very common. The women reported being left alone, being sent outdoors while their moms took drugs in the home, being removed from their homes, and sent to foster care or kicked out by their parents.
Studies of male offenders also reveal significant experience of trauma and abuse. In her book, Prologue to Violence, Stein (2007) interviewed men waiting for medical evaluation in a prison hospital ward. Eighty percent reported having been physically assaulted during childhood and almost half of those “endured grisly episodes of maltreatment” (p. 2) including burns, broken bones, and ongoing sexual molestation. Kamphuis and Emmelkamp (2005) point out that while most research focuses on victims of a single traumatic event, recent research suggests that those exposed to repetitive and enduring interpersonal violence are particularly vulnerable, a point that is very relevant for our child abuse topic.
These examples assume that abuse causes trauma and empirical tests so far confirm this assumption. Some authors have operationalized trauma and tested its association with violence. In a national sample, Boney-McCoy and Finklehor (1995) found large correlations between various types of victimization and PTSD symptoms as did Paolucci et al. (2001). Silverman et al. (1996) also report greater PTSD in male physically abused subjects than nonabusedsubjects. Levendosky, Huth-Bocks, and Semel (2002) also found that a history of child abuse was significantly associated with trauma symptoms.
The diagnostic criteria for PTSD in DSM-5 include the experience of a traumatic event in the form of a physical threat causing clear distress; intrusive memories; psychological distress or physical symptoms when reminded of the trauma; active avoidance of reminders of the trauma; inability to recall important aspects of the traumatic event; pervasive numbing of general responsiveness such as feeling detachment from others or having a restricted range of emotion, and persistent symptoms of increased arousal such as difficulty sleeping, irritable outbursts, and hypervigilance (American Psychiatric Association, 2013; also see Creamer, 2000). Thus outcomes of trauma, such as stress, numbing and detachment, and problems with emotional regulation, might easily increase the chance of violent behavior.
One symptom of concern is dissociation. In Stein’s (2007) sample, almost 25% of the offenders she interviewed had experienced intense episodes of dissociation. She reasons that “Severely traumatized persons may undergo a kind of defensive cauterization, so that highly charged somatosensory data remain diffuse and inaccessible for higher levels of neural processing” (p. 4). She explains that neurological systems are sensitive to stress, especially when stress is chronic. The traumatic impact in child abuse is doubly insidious: “The pervasive, elemental stressor in child abuse includes not only a disorganizing physical assault but also the relational paradigm of continued dependence on the abuser. Daily, nonabusive interactions with the caretaker are highly charged; each “normal” engagement can contain multiple triggers for anxiety that, we now know, take a massive physiological toll. These encounters may prompt a cascade of neuropathic interactions that negatively affect brain growth, lateralization and specialization” (p. 30). Dissociative symptoms in abused children have been linked to disruption of the endogenous opiate systems, the shrinkage of the corpus callosum (signaling possible disruption in connectivity between the two brain hemispheres), and longterm effects on the production of hormonal stress regulators like cortisol (Stein, 2007). Very early neglect is hypothesized to disrupt the development of neural connections important for talking, causing permanent linguistic deficits (Stein, 2007). Some have proposed that a parallel processing system develops, where memories are unelaborated by language (Stein, 2007). This leads to the hypothesis that subsequent adverse experiences and traumata could easily be stored in parallel, without the benefit of explicit processing. It is also likely that traumatic abuse causes disruptions in the processing of emotions. Kent (1976) observed emotional withdrawal in 51% of the physically abused and 59% of the neglected children in their sample of foster children.