Borderline and histrionic personality traits represent Cluster B patterns characterized by dramatic, erratic behaviors, emotional intensity, and unstable interpersonal relationships. In ordinary settings these traits can lead to distress and dysfunction, but in extreme environments such as military combat units, remote expeditions, and space missions, their impact may be especially deleterious. These environments demand exceptional teamwork, stability, and emotional regulation; yet individuals with borderline or histrionic traits often struggle with interpersonal dysfunction, emotional dysregulation, and impulsivity. Moreover, tendencies toward hypersexuality or boundary violations can undermine group cohesion and mission focus. This article examines the neurobiological underpinnings of borderline and histrionic personality features (e.g. limbic hyperreactivity, prefrontal dysregulation, stress-axis instability) and analyzes how these traits manifest in high-stakes, confined team settings.
