The article discusses the variable nature of cognitive control, proposing a Dual-Mechanisms of Control (DMC) framework to explain the intrinsic variability in cognitive control. The DMC framework posits two distinct modes of control: proactive control, which involves sustained and anticipatory maintenance of goal-relevant information in the lateral prefrontal cortex (PFC), and reactive control, which reflects transient, stimulus-driven goal reactivation. The framework explains three sources of cognitive control variation—intra-individual, inter-individual, and between-groups—by distinguishing between these two control modes. Proactive control is associated with sustained PFC activation, while reactive control is linked to transient activation. The DMC framework also suggests that individual differences in traits such as fluid intelligence and personality factors influence the preference for proactive or reactive control. Additionally, the framework helps explain cognitive impairment in different populations, such as older adults and individuals with schizophrenia, by showing a shift from proactive to reactive control. The article concludes by highlighting the potential for the DMC framework to guide cognitive intervention strategies.The article discusses the variable nature of cognitive control, proposing a Dual-Mechanisms of Control (DMC) framework to explain the intrinsic variability in cognitive control. The DMC framework posits two distinct modes of control: proactive control, which involves sustained and anticipatory maintenance of goal-relevant information in the lateral prefrontal cortex (PFC), and reactive control, which reflects transient, stimulus-driven goal reactivation. The framework explains three sources of cognitive control variation—intra-individual, inter-individual, and between-groups—by distinguishing between these two control modes. Proactive control is associated with sustained PFC activation, while reactive control is linked to transient activation. The DMC framework also suggests that individual differences in traits such as fluid intelligence and personality factors influence the preference for proactive or reactive control. Additionally, the framework helps explain cognitive impairment in different populations, such as older adults and individuals with schizophrenia, by showing a shift from proactive to reactive control. The article concludes by highlighting the potential for the DMC framework to guide cognitive intervention strategies.