When it comes to the complexity of human behavior, no behavior is more intricate than the social nets we weave. In complex social networks, empathy is an important key to social behavior, but because it is felt emotionally complicates the matter. When it comes to the brain and personality, many people might be aware of the idea of “nature versus nurture” — that each person’s emotional and psychological makeup is affected by genetics and life experiences. Emotions are complicated, however, because they are subjective and thus hard to measure. As an emotion, one might easily dismiss the neurological basis of empathy and, in attempting to understand individuals who cannot feel empathy, assume the difference is simply perspective. But one thing points to a deep neurological difference: the incredible discovery of what psychologists and neuroscientists call “acquired sociopathy.”
One thing points to a deep neurological difference: the incredible discovery of what psychologists and neuroscientists call “acquired sociopathy.”
“Acquired sociopathy” is the phenomenon where, after an individual has sustained severe brain damage, an individual’s personality changes drastically. The person may gain sociopathic traits such as increased aggression and the inability to understand others’ emotions. This points to something fascinating in the development of sociopathy. While genetics may predispose someone to sociopathy, lived experiences often catalyze the condition. Negative psychological experiences, such as trauma or neglect, during periods of early development can reduce an individual’s care for others, but acquired sociopathy points clearly to a neurological element underpinning a lack of empathy. Moreover, studies on acquired sociopathy reveal some of the cognitive processes included in empathy.
A study in Brain: A Journal of Neurology examined one such individual known as JS. In November 1997, JS was admitted to a hospital after he was found unconscious. Doctors discovered brain trauma indicative of stroke caused by a general convulsion. After hospitalization, he was reported as “gravely disturbed” and had several “unpredictable episodes of aggression,” yet relatives described him as “a quiet, rather withdrawn person who was never aggressive.” In particular, JS had brain trauma primarily in the orbitofrontal cortex. This portion of the brain has been associated with acquired sociopathy since the late 1980s when the first individual with acquired sociopathy was studied and the term introduced.
According to this hypothesis, the body and mind physically respond to social situations in a way that directs attention to possible negative outcomes of social interaction.
Since that first case, experts have developed many hypotheses on why sociopathy might be associated with atypical social behavior, the most widely accepted being the idea of a “somatic marker system” by Antonio Damasio. In this hypothesis, the mind “tags” certain social situations and has an “autonomic nervous system response” unique to each social situation. An autonomic response is something that someone experiences unconsciously, such as heart rate, hunger, respiratory rate, or arousal. According to this hypothesis, the body and mind physically respond to social situations in a way that directs attention to possible negative outcomes of social interaction, guiding people toward positive outcomes and acting as a warning system. This hypothesized autonomic response would be analogous to a physical experience of emotion, like empathy or other especially social emotions like anxiety or humiliation. In line with this, studies of patients with trauma to the frontal cortex have shown these patients do not have an autonomic response when passively viewing pictures of disaster, mutilation, or nudity. Interestingly, patients did have autonomic responses in active viewing — viewing when asked to pay special attention to a picture or scene. This might indicate that acquired sociopathy does not mean the inability to recognize the emotions of others but instead means a lack of emotional response occurs unless the individual’s attention is externally directed to the emotions of others.
In the case of JS, his scores on tests, which were designed to measure an individual’s recognition of others’ emotions, were incredibly low for the average person with sociopathy. This was true in both passive and active viewing, showing perhaps that the trauma to his frontal cortex contributed especially to a lack of recognition of emotions. The wealth of research leaves unclear whether this cognitive or emotional process is the only one involved in sociopathy. As any neurologist will tell you, the brain in its adaptability can achieve a great many things, and each person’s brain varies greatly. With trends in neurotypical or non-neurotypical psychology there is often a spectrum — something well accepted not only for conditions such as sociopathy, but also others such as autism, attention deficit disorder, and depression. In other words, multiple factors contribute to how these conditions present. Research into acquired sociopathy, as one manifestation of the disorder, reveals some of the ways in which it develops and functions, both psychologically and neurologically.
Brain(2000). DOI: 10.1093/brain/123.6.1122
