While phenotypically indistinguishable with respect to callousness, individuals with primary and secondary callous–unemotional (CU) traits may show different developmental outcomes. This research predominantly comprised cross-sectional studies of male participants with a focus on maladaptive correlates. Thus, the present study examined whether youth with primary and secondary CU traits identified in Grade 7 reported distinct maladaptive outcomes (internalizing, externalizing, and substance use problems; criminal offenses; and sexual and partner experiences) and adaptive outcomes (health and wellbeing, education, and employment) in adulthood at age 25. We also examined sex differences. Participants included the high-risk control and normative samples from the Fast Track project (N = 754, male = 58%, Black = 46%). Youth with secondary CU traits reported higher levels of adult internalizing and externalizing psychopathology, a greater number of sexual partners and risky sexual behavior, and a greater number of violent offenses, compared with individuals with primary CU traits and those with low CU and anxiety symptoms. Conversely, youth with primary CU traits and low symptoms had higher wellbeing and happiness scores than those with secondary CU traits. Finally, there was differentiation on outcomes between female primary and secondary CU variants and male primary and secondary CU variants.