In humans, hand performance has evolved from a crude multi-digit grasp to skilled individuated finger movements. However, control of the fingers is not completely independent. While musculotendinous factors can limit independent movements, constraints in supraspinal control are more important. Most previous studies examined either finger flexion or extension of the digits. We studied differences in voluntary force production by the five digits, in both flexion and extension tasks. Eleven healthy subjects were instructed to flex or extend maximally their digits, in all single- and multi-digit combinations. They received visual feedback of total force produced by 'instructed' digits and had to ignore 'non-instructed' digits. Despite attempts to flex or extend instructed digits maximally, subjects rarely generated their 'maximal' force, resulting in a 'force deficit' and produced forces with non-instructed digits ('enslavement'). Subjects performed differently in flexion and extension tasks. Enslavement was greater in extension than flexion tasks (p=0.019), while the force deficit in multi-digit tasks was smaller in extension (p=0.035). The difference between flexion and extension in the relationships between the enslavement and force deficit suggests a difference in balance of spill-over of neural drive to agonists acting on neighboring digits and focal neural drive to antagonist muscles. An increase in drive to antagonists would lead to more individualized movements. The pattern of force production matches the daily use of the digits. These results reveal a neural control system which preferentially lifts fingers together by extension but allows an individual digit to flex so that the finger pads can explore and grasp.