Why do people assume blonde women are the least intelligent?

Excellent point.  

Oh yes, you also forgot the V-Hats on top and seizures in public.

That's true, fake hair colors look good on clowns, but stupid on people. Idk, maybe there used to be a really dumb blond some time ago in history that accounts for the bad impression about being blond. 

stereotyping ..................................

And adventurous my guess would be becsuse they are good explorers. Maybe being smart just isnt that important to them. Who knows...

Blonde jokes were very popular in the 80's, just shows how much we have grown.  It is the same discrimination and prejudices from people who thinks making fun of others is ok.  It isn't I can remember laughing at those jokes somehow one gets enlightened when becoming more mature and recognize how this is not appropriate, growing up in mind and body.  Unfortunately it is not always the case, you can't change all of the people speaking out against it helps to stop the behaviour.

It’s just a ridiculous stereotype.

You are on to something there, besides bottle blonde or not they are far more attractive then some goth chic with puke colored hair...

I try never to judge a book by its cover.   You just never know who you're dealing with.