It is commonly assumed that individuals tend to avoid effort, be it physical or cognitive. Yet, recent evidence suggests that individual differences exist and that personality traits related to the willingness to invest cognitive effort in goal-directed behavior are associated with experimental measures of cognitive effort investment. The personality traits need for cognition (NFC) and self-control were found to be related to behavioral measures of effort discounting and demand avoidance, respectively. Given that NFC and self-control are only moderately related, this evidence raises the question whether these associations are specific for these traits or whether they reflect a common core that these traits both involve cognitive effort investment. If so, the common core of both traits might be related to behavioral measures of the avoidance of cognitive effort in a more systematic fashion. Thus, the present study aimed at specifying a core construct of cognitive effort investment that reflects dispositional differences in the willingness and tendency to exert effortful control. Therefore, we conducted an online-study (N = 613) with questionnaires related to cognitive motivation and effort investment including the NFC and the self-control scale. Our findings support the hypothesized correlations between the assessed traits, where the relationship of NFC and self-control is specifically mediated via an aspect that can be conceptualized as goal-directedness. We found that a hierarchical factor model of cognitive motivation and effortful self-control can explain the shared variance of these two first-order factors by a second-order factor of cognitive effort investment. These findings are backed up by results of an independent second sample (N = 244). Taken together, our results integrate currently only loosely related research strands on cognitive motivation and self-control and provide a basis for further experimental research on the role of dispositional individual differences in goal-directed behavior.