Boys vs. Girls??

Maybe it's hard-coded into DNA but seriously....my kids are being taught the exact same things. I don't say "Hey son - the rules are different for you since you're a boy." and I don't say "daughter - you have different rules because you're a girl." I really don't....and yet.....

Why is it that my daughter can put the toilet seat lid down when she is done (un-prompted, mind you) and yet at least once a day I have to have my son return to the bathroom to close the lid?

And why oh why can my 3.5 year old daughter change the roll of toilet paper *by herself* but my 6.5 year old son will just leave the empty roll for someone else to change?

It just has to be genetics.