But this evening I was grocery shopping and I heard someone whistling a lazy, happy tune. I looked over my shoulder, and up the aisle was a woman pushing a cart and whistling absently as she scanned the shelves.  
   
 It occurred to me that whistling to one's self is another thing that I generally associate as a male characteristic. Women might hum, but IMLE, I can't remember a woman whistling. Is this a cultural difference? Is there something about the male and female make-up? Are there other differences like this that we scarcely notice?  
   
 Or do women whistle all the time and I just haven't noticed? Aside from from the lovelies whistling at Drunk Asian wherever he goes.