How Come?: "Women Drivers"

How Come 95 times out of 100, just by observing a vehicle driving along, or especially while PARKING... you can scientifically determine guess correctly that there is a lady at the wheel?

Is it a genetic predisposition garnered by having double X chromosomes (nature)?

Or is it because these ladies are given strange instructions when they are learning to drive (nurture)?

Maybe it's a mixture of nature and nurture... - QBF