Panic and Agoraphobia

The chapter discusses panic disorder and agoraphobia. Panic disorder is defined by recurring panic attacks, dramatic episodes in which a surge of autonomic activity is accompanied by rapidly escalating levels of fear and distress. Agoraphobia is the persistent fear of open or confined spaces, which often develops as a secondary response to panic attacks. After an overview of these disorders, their developmental features, and the main risk factors identified in the epidemiological literature, the chapter critically reviews existing evolutionary models and suggests new directions for research. The final section applies the criteria developed earlier in the book to classify the disorders within the FSD model. The author concludes that panic and agoraphobia can be classified as defense activation (D-type) conditions.

The Schizophrenia Spectrum

The chapter discusses schizophrenia spectrum disorders (SSDs), including schizophrenia and schizotypal personality disorder (SPD). Schizophrenia and related disorders are part of the broader spectrum of psychosis, a cluster of genetically and phenotypically related conditions marked by loss of contact with external reality. After an overview of these disorders, their developmental features, and the main risk factors identified in the epidemiological literature, the chapter critically reviews existing evolutionary models and suggests new directions for research. The final section applies the criteria developed earlier in the book to classify the disorders within the fast-slow-defense (FSD) model and identify functionally distinct subtypes. The author concludes that most instances of SSDs can be classified as fast spectrum (F-type) conditions; however, there are indications of heterogeneity within these conditions, and future research is likely to identify exceptions to the general pattern.

The Life History Framework and the FSD Model

The chapter presents a life history framework for psychopathology and introduces the fast-slow-defense (FSD) model, a three-way taxonomy that distinguishes between fast spectrum (F-type), slow spectrum (S-type), and defense activation disorders (D-type). Each type of disorder is associated with specific patterns of risk factors, sex differences, and developmental features (e.g., age of onset). The chapter also explores additional implications of the model and considers the role of general intelligence in the origin of psychopathology, The chapter ends with a detailed comparison between the FSD model and transdiagnostic models based on the distinction between internalizing and externalizing disorders (and, more recently, a general “p factor” of psychopathology).

Life History Strategies

The chapter introduces the basics of life history theory, the concept of life history strategy, and the fast–slow continuum of variation. After reviewing applications to animal behavior and physiology, the chapter reviews current theory and evidence on individual differences in humans as manifestations of alternative life history strategies. The chapter first presents a “basic model” of human life history–related traits, then advances an “extended model” that identifies multiple cognitive-behavioral profiles within fast and slow strategies. Specifically, it is proposed that slow strategies comprise prosocial/caregiving and skilled/provisioning profiles, whereas fast strategies comprise antisocial/exploitative and seductive/creative profiles. The chapter also reviews potential neurobiological markers of life history variation and considers key methodological issues in this area.

A Look at the Future

The closing chapter considers the present state of evolutionary psychopathology and discusses three areas of future development: proximate mechanisms, from molecular genetics and epigenetics to neurobiological and computational models; epidemiology, with an emphasis on “deep epidemiology” and the interplay between inherited risk factors and current environmental conditions; and developmental psychopathology. An evolutionary perspective on mental disorders can inform emerging approaches such as computational psychiatry, and help refine the predictions of developmental and epidemiological research. Conversely, these approaches provide crucial insights into the proximate mechanisms that underlie both normal and pathological functioning. The author concludes that the field of evolutionary psychopathology must embrace theoretical integration if it is to produce a set of organizing principles flexible enough to accommodate a multiplicity of specific models and hypotheses, but also capable of explaining broad epidemiological and comorbidity patterns and supporting a biologically informed classification of disorders.

Posttraumatic Stress Disorder

The chapter discusses posttraumatic stress disorder (PTSD). PTSD is a severe, prolonged response to witnessing or experiencing traumatic events that may manifest with a variety of cognitive, affective, and physiological symptoms, from irritability and hypervigilance to recurrent dreams and flashbacks. After an overview of this disorder, its developmental features, and the main risk factors identified in the epidemiological literature, the chapter critically reviews existing evolutionary models and suggests new directions for research. The final section applies the criteria developed earlier in the book to classify the disorder within the fast-slow-defense (FSD) model. The author concludes that PTSD can be classified as a defense activation (D-type) condition.

Social Anxiety Disorder

The chapter discusses social anxiety disorder (SAD) or “social phobia”, a condition marked by persistent fears and/or anxieties about social situations (including public speaking and other types of performance) that expose the person to scrutiny by others. After an overview of this disorder, its developmental features, and the main risk factors identified in the epidemiological literature, the chapter critically reviews existing evolutionary models and suggests new directions for research. The final section applies the criteria developed earlier in the book to classify the disorder within the fast-slow-defense (FSD) model. The author concludes that SAD can be classified as a defense activation (D-type) condition.

Specific Phobias

The chapter discusses specific phobias, one of the most common categories of psychopathology. Phobias are exaggerated fears of particular objects of situations, from animals and heights to flying and being exposed to blood, injections, and injuries. After an overview of these disorders, their developmental features, and the main risk factors identified in the epidemiological literature, the chapter critically reviews existing evolutionary models and suggests new directions for research. The final section applies the criteria developed earlier in the book to classify the disorders within the fast-slow-defense (FSD) model. The author concludes that phobias can be classified as defense activation (D-type) conditions.

Attention-Deficit/Hyperactivity Disorder

The chapter discusses attention-deficit/hyperactivity disorder (ADHD), a heterogeneous set of conditions marked by clinically significant levels of hyperactivity, impulsivity, and inattention. After an overview of this disorder, its developmental features, and the main risk factors identified in the epidemiological literature, the chapter critically reviews existing evolutionary models and suggests new directions for research. The final section applies the criteria developed earlier in the book to classify the disorder within the fast-slow-defense (FSD) model and identify functionally distinct subtypes. The author proposes to tentatively distinguish between three subtypes of ADHD: a high-frequency fast spectrum subtype overlapping with conduct/antisocial disorders and psychosis (F-ADHD), a low-frequency slow spectrum subtype overlapping with autism (S-ADHD), and a subtype unrelated to life history variation and characterized by low general intelligence and generalized cognitive impairment.

The Autism Spectrum

The chapter discusses autism spectrum disorder (ASD). Autism is defined by a triad of symptoms: impairments in social interaction, impairments in communication, and restricted/repetitive behaviors and interests. After an overview of this disorder, its developmental features, and the main risk factors identified in the epidemiological literature, the chapter critically reviews existing evolutionary models and suggests new directions for research. The final section applies the criteria developed earlier in the book to classify the disorder within the fast-slow-defense (FSD) model and identify functionally distinct subtypes. The author proposes to distinguish between a slow spectrum subtype with normal or high IQ and a major role of common alleles (S-ASD) and a subtype unrelated to life history variation, with high rates of intellectual disability and a major role of rare and de novo mutations (O-ASD).