They needed a professional study to determine what ANY 12 year old boy or girl would have been happy to tell them,as well as startled that someone would be so foolish as to ask?
AFATG,you could probably drop the age to 8 and get the same answer.
Or even 70-something if you still so foolish you need to ask.
AND.......one final throught,which is "VIVA LA DIFFERENCE!" Men,WOMEN,AND THE SURVIVAL AND ADVANCEMENT OF THE HUMAN SPECIES HAS ALWAYS DEPENDED ON THESE DIFFERENT OUTLOOKS TO ENCOURAGE QUESTIONS THAT TEACH US ALL ABOUT DIFFERENT WAYS TO THINK AS WELL AS TO CONSIDER THAT THERE ARE LEGITIMATE QUESTIONS THAT NEED ANSWERS WE NEVER WOULD HAVE STUMBLED UPON IF SOMEONE HADN'T BROUGHT OUR ATTENTION TO IT/
I will even go so far as to say,and it pains me to say this,that without the different mindset of women,it is likely that civilization as we know it wouldn't exist. Men may have been happy to live as hunters and gatherers,but it took women bitching at them about better and safer living conditions for the women and children that got that rock rolling down the hill.