Or rather, the lack of:

Women now account for more than 50% of American medical students, but only 10% of neurosurgery residents . . .

. . . Women account for less than 6% of the neurosurgery ranks.

Studies show that female physicians prefer flexible hours, which leads women to pursue part-time jobs out of residency.

Neurosurgery, with often unpredictable hours and long surgeries, is simply not conducive to this kind of schedule.

The lack of female role-models or discrimination within the field are unlikely reasons for the dearth of female neurosurgeons.

Lifestyle is king, and it is the dominant priority with the current generation of doctors.