The current experiments investigated the fractal structure in the nested actions of tapping behavior. The results revealed that task constraints (e.g., tapping to a metronome) alter the fractal structure of a given aspect of the behavior (e.g., inter-tap interval) and decouple its long-term interactions with other aspects of the behavior (e.g., key-press duration). These results support the idea that fractal structure reflects the dynamical organization of complex systems.