[Neurobiological hypothesis relating to connections between psychopathy and childhood maltreatment]

This article aims to closely link maltreatment subjected in childhood with the psychopathy, which is characterised by 2 factors: factor one: callousness, lack of guilt, emotional shallowness; factor two: antisocial behaviour, violence and impulsivity. If the parental education system seems to have an effect on the development of "factor two", "factor one" is for the authors of unknown aetiology. I will try to theorize that harsh and chronic maltreatment could be responsible for this emotional impairment which characterizes psychopathic individuals.

There's a wealth of literature on the consequences of maltreatment on the brain's development in childhood, which are considered from a stress point of view, some individuals developing a syndrome called "post-traumatic stress disorder": PTSD (Perry, Shore, Van der Kolk, Teicher, Bremner, Carrion, De Bellis, Lanius, Nutt...). With prolonged chronic stress, the hypothalamic-pituitary-adrenal (HPA) axis is hyper-activated, with the resulting release in adrenocorticotropin and cortisol, which involves structural changes, cell atrophy and neuronal loss. According to the authors, there are 2 responses to harsh or chronic stress: dissociation (numbing) which involves the parasympathetic system, and hyperarousal which involves the sympathetic system. One of the worst neurobiological effects of repeated stress is amygdala kindling. Many laboratory studies on physiological alterations of amygdala in rats show that kindling interferes with the acquisition of fear conditioning.

Now, fear conditioning is the model on which the abusive education system is based. If this cannot develop, the child lives in the present, reacting to the unconditioned stimulus (US) like blows (with autonomic reactions), but the emotional association between this and the conditioned stimulus (CS) -- like hostile glances or shouting -- could not be registered in the orbital frontal cortex and the conditioned stimulus would not provoke autonomic responses which enable the anticipation of a danger connected with an interdict. Thus, psychopathic tendencies can develop.