Comm101- default assumptions

The story about the father and son getting into a car crash, in chapter 5, almost got me.  I thought I was fooled for a while there.  How often do we assume that the people in highly esteemed positions such as a surgeon, are men?  When do we assume it will be a women?  I can't wrap my mind on how or why I think this.  I gotta be honest.   A position like that I would assume that it will be a man.  Then again, the only reason I would assume something like that would probably come from experience only.  

In the work that I do now, there are a fair amount of women and men that are in executive positions.  They work just as hard and effectively as the men.  A couple of them even more so.

For some reason I refer to default in my thought process as who to expect in a certain topic like this one.  Are the words we use that basic?  If we were to be told a story about the greatest warrior that ever lived, how many of us would imagine a man to have something to refer to?

It's probably due to our cultural history that has developed this thought process.  Media can also paint a picture of the roles of men and women in this day and age, even if some seem ridiculous.