This study examined associations of psychopathy facets of boldness, meanness, and disinhibition with clinically relevant variables and physiological reactivity to affective stimuli. These associations were examined after accounting for developmental associations with adolescent psychopathic traits, namely callous–unemotional traits, narcissism, and impulsivity. Psychopathic traits were assessed during adolescence using the Antisocial Process Screening Device and the Inventory of Callous Unemotional traits and during young adulthood via the Triarchic Psychopathy Measure. Clinical variables (N = 99, Mage = 15.91, 53% female), as well as affective and physiological responses (heart rate, skin conductance, startle modulation) to violent and erotic videos (N = 88, Mage = 19.92, 50% female) were also assessed during adulthood. After accounting for adolescent psychopathic traits, boldness was associated with high cognitive reappraisal and low anxiety, fear, and hostility, and meanness was related to callous–unemotional traits, hostility, less sympathy to victims, and less use of cognitive reappraisal. Disinhibition, by contrast, was associated with impulsivity, increased anxiety, and hostile and aggressive tendencies, as well as conduct disorder, antisocial personality disorder symptoms, and cognitive suppression. In addition, evidence was found for different physiological measures operating as biological indicators of these distinctive dimensions, with reduced resting heart rate and cardiac reactivity to violent stimuli indicative of boldness, above and beyond adolescent psychopathic traits, and low startle potentiation for violent stimuli indicative of callous–unemotional traits and meanness. These findings provide evidence for the value of a multidomain approach for clarifying neurobiological mechanisms of psychopathic tendencies that can inform prevention and treatment efforts.