What’s the difference between a blonde and a brunette? Recent research from Stanford University shows that despite the many adjectives associated with being blonde, what separates the towheaded from the rest has nothing to do with the stereotype.
According to a paper published this month in Nature Genetics, the blonde trait occurs when one letter among the 3 billion building blocks that make up the human genome sequence is expressed as an "A" instead of a "G" — a mutation, they found, that is not associated with any other traits. So if you're blonde and having more fun, it has absolutely nothing to do with science. "This is a great biological example of how traits can be controlled, and what a superficial difference blond hair color really is," explains lead researcher David Kinglsey to National Geographic. A great example of how traits can be controlled — and an even better retort for dumb blonde jokes.