Abstract: Psychopathy refers to a heterogeneous set of harmful dark traits and behaviors, including superficial charm, callousness, irresponsibility, and antisocial behavior. The triarchic psychopathy model (TriPM) posits that psychopathy is the combination of three traits: boldness, disinhibition, and meanness. However, little research has examined the concurrent and developmental correlates of these traits. We developed TriPM scales from the NEO Personality Inventory-Revised using an empirical-derived approach in a high-risk sample of 561 young adults (ages 17–25; 70.2% male). Concurrent correlates and developmental precursors of each scale were examined longitudinally using cross-informant reports from three critical developmental periods (ages 3–5; 9–11; 15–17). Using this approach, we identified consistent developmental precursors and concurrent correlates of boldness, including lower reactive control, fewer internalizing traits, and greater resiliency. Additionally, starting in adolescence we found that disinhibition was related to lower reactive control, more externalizing problems, substance use, and internalizing traits. Finally, although meanness demonstrated some expected concurrent relationships with criterion variables in early adulthood (e.g., lower adaptive functioning), we identified few consistent developmental precursors of meanness. Thus, a NEObased approach to measuring the TriPM was successful in delineating boldness, disinhibition, and, to a lesser extent, meanness cross-sectionally during early adulthood. However, only boldness showed relative stability from dvelopmental precursors in early childhood to our TriPM scale in early adulthood.