Antisocial personality disorder (ASPD) is a mental condition in which a person exhibits a pattern of repeated disregard for and violation of others’ rights. The Diagnostic and Statistical Manual of Mental Disorders (DSM) provides the framework for diagnosing ASPD. The prevalence rate of ASPD is high in prisons. Genetics, epigenetics, neuroscience, sociology, epidemiology, psychology, and other behavioral science fields have attempted to find a primary etiology. Despite decades of research, the precise etiology of ASPD has not been found, and its pathophysiology remains a complex question. The interaction between genes and the environment appears to be a significant factor in the development of ASPD. Brain imaging in subjects with ASPD has revealed structural brain changes in those with ASPD. Individuals with ASPD are challenging to manage for health care providers because of their complicated clinical presentation, high comorbidity of medical and mental disorders, lack of licensed pharmacotherapies for ASPD, and increased utilization of healthcare resources. ASPD requires tremendous effort from treating clinicians. Clinicians can successfully manage individuals with ASPD if they remain aware of the unique challenges of these patients while thoughtfully applying available research.

This chapter describes pseudoscience and questionable ideas related to antisocial personality disorder. The chapter opens by considering diagnostic controversies such as the construct of psychopathy. Questionable assessment practices and myths that influence treatment are also addressed. Dubious treatments include psychedelics, psychoanalysis, and punishment-based interventions. The chapter closes by reviewing research-supported approaches.

Although the primary aim of Just as Deadly is to present information on female serial killers (FSKs), the author discusses a comparison of FSKs and male serial killers (MSKs) to illustrate the dramatic differences between their crimes. As described in Evolutionary Behavioral Sciences, the author and her team investigated sex differences in serial murder through an evolutionary psychological lens but also collected data on other background and mental health variables, as empirical comparisons of FSKs and MSKs are virtually nonexistent in the scientific literature. Data collected from 55 MSKs and 55 FSKs revealed sex differences in relationship status, educational attainment, and socioeconomic status. Moreover, nearly 90% of MSKs and 43% of FSKs had reported mental health issues. These results show that MSKs have more than a fourfold chance of having a mental illness compared to the population and are twice as likely as FSKs to have documented issues. The cases of MSKs Ed Gein and John Wayne Gacy describe mental illness issues and are used to demonstrate drastic differences in serial murder modus operandi and victims.

A single perspective cannot explain the entirety of serial murder. In psychology, we promote a biopsychosocial model of understanding any behavior or mental process. The author provides a summary of various perspectives, starting with behavioral neuroscience (i.e., biopsychology). She summarizes direct evidence from case studies showing neural issues in serial murderers, implied evidence of brain dysfunction of serial murders, and evidence of no neural issues in serial murderers. She then discusses the biological correlates of violence in general. The case of MSK Joseph DeAngelo highlights crime solved through forensic genetic genealogy.

People are susceptible to boredom and seek an optimal level of arousal. Psychopathic individuals appear to be low on arousal, and they try to elevate this by seeking novelty and taking risks. Ways to achieve the optimal level by sensation-seeking include transgressions such as violence, arson and theft. These can have sexual associations and are sometimes accompanied by masturbation. Dopamine activation is at the basis of elevations in arousal. Serial lust killers commonly have a history of committing non-sexual crimes and arson. The internal organs of the body are under the control of the autonomic nervous system, high arousal being associated with dominance of the sympathetic branch and low arousal with the parasympathetic branch. Arousal is largely non-specific, and it takes a positive or negative value according to context. Switches can be made from negative to positive, which appears to lie at the basis of some lust killing.

Serial killers tend to score highly on a scale of psychopathy, ticking boxes such as low empathy and glib superficial charm. Another condition that can be tapped to derive insights is anti-social personality disorder (APD). Some reports of the experiences of lust killers point to a split in individual consciousness, sometimes expressed as good versus bad personalities. There can be a sudden flip between these states. This is sometimes conceptualized as dissociation and can be revealed as ‘voices in the head’. It is distinct from psychosis and has not been successful as a plea for mitigation. Characteristics of dissociation include viewing oneself from a distance, having a poor or no memory of the killing (i.e. memory specific to the state at the time of the killing) or seeing a disliked person as the target of the attack. Some serial killers are diagnosed as psychotic.

The nosological background is outlined, with particular reference to the fifth edition of the American Psychological Association's Diagnostic and Statistical Manual and the International Classification of Disease's eleventh iteration. Categorical diagnoses of antisocial personality disorder are critiqued. The question of what motivates people to engage with others, and how this may be lacking in antisocial individuals, is addressed. It is emphasised that to understand what people are like and why they behave the way they do, we need to look at both traits and values – the latter being goals that people find desirable and use as guides for their behaviour across different situations. The importance of motivation for an understanding of personality pathology is outlined in the context of a schema that re-describes PD in terms of an ‘approach vs withdrawal’ dimension that is fundamental to human motivation. Finally, the question ‘How does personality become pathological?’ is raised.

Starting with a discussion of antisocial personality disorder as a diagnostic construct, this chapter argues that models of mental disorders should focus on symptoms (and individual traits) rather than on flawed diagnostic syndromes. It is argued that interpersonal antagonism, callousness and hostility lie at the core of antisocial personality, which is broader than the constructs – ASPD and psychopathy – with which it is traditionally associated. Paranoia and boredom proneness are considered as key elements of antisocial personality. Assessment of antisocial individuals should consider the three aspects of self: self as social actor, self as motivated agent, and self as autobiographical author, as well as their location on the prosocial-antisocial continuum. Arising from the assessment, a case formulation should seek to articulate the central mechanisms that cause and maintain the individual's main problems and to explain how they are related. When an individual shows violent behaviour it is important that the case formulation identifies the type of violence that is shown and the functions it serves. Consistent with the Good Lives Model (GLM), it is important that positive aspects are included in a strength-based case formulation, covering areas such as work, relationships, accommodation, health and leisure activities.

This chapter reviews what is known about the interpersonal style of people with antisocial personality and psychopathy, concluding that antisocial individuals have a cold, vindictive and hostile interpersonal style and that they lack the motivation to engage in an empathic way with others. The triarchic view of human selfhood– the self as social actor, as motivated agent and as autobiographical author – is introduced as a framework within which the antisocial individual might be understood from a first-person perspective. So-called dark traits are considered, particularly their role in sexual offending and sexual sadism. It is suggested the ‘dark traits’ construct might be expanded to include paranoia, moral disengagement, spitefulness and greed. The concept of ‘emotion goals’ is introduced and considered in relation to a quadripartite typology of violence that sees violence as reflecting appetitive versus aversive motivation interacting with an impulsive versus controlled dimension.

This chapter seeks to provide an overview of several major categories of psychological theories that have been developed and studied over the years to explain violent behaviour. For the purposes of the chapter, we have adopted Christopher Webster et al al’s (1997) conception definition of violence as an intentional act of threatened, attempted, or actual physical and/or psychological harm directed against a non-consenting person. Though this definition is somewhat narrow, excluding dynamic shifts in perspectives on what constitutes violence, it corresponds with much of the existing psychological literature. As part of this review, the following subjects are discussed: (1) a definition of violent behaviour to guide our subsequent reviews, (2) neuropsychological and developmental factors, (3) social cognition and the intersecting roles of affect and cognition, and (4) personality disorders and psychopathy.