There's actually a pretty extensive article in Wikipedia that addresses the origins of the myth.
If it is a myth.
Here are more opinions and answers from other WikiAnswers contributors:
I personally think that most blondes are pretty smart. Not only smart but hot, funny, kind, and trustworthy.
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Excuse me, but I am a blonde and I get straight A's. Blondes in general are not stupid even though some get their "dumb blonde" moments.
The 'dumb blonde' myth has its origins in early 18th-century literature, where blonde women were often portrayed as naïve or promiscuous. Over time, this stereotype became pervasive in popular culture through various forms of media, perpetuating the idea that blonde women are unintelligent.
Being blonde doesn't make you dumb, that is just a untrue stereotype.
No, it is highly impossible for a person to get fired for calling someone a dumb blonde.
to have a blonde moment is to do or say something really dumb
Yes because they are mentally challenged and they are dumb
Yes, Bushra Shamim is a blonde because she is dumb like a dumb blonde and has no idea what is going on in her life except for her obsession over Justin Bieber and Music.
Is that a squirrel on your face?
dumb blonde
because why
Jacob tells Rosalie three dumb blonde jokes.
A dumb blond is a girl or guy with blonde hair that is either stupid or forgetful A dumb brown is a girl or guy with brown hair that is either stupid or forgetful Kazzc Kaz
Christianity
wave at her