A Google for the "researcher" cited by this report fails to show any returns other than repetitions of the article.

I'm inclined to believe this blog (about the third comment down):

"Any warning bells yet? Of course this is another made-up story from the Weekly World News, brought online through Yahoo! entertainment. Dr. Yvonne Rossdale does not exist, and the study is just made up.
That didn't prevent the Norwegian online newspaper Nettavisen from bringing this great news to all our local large breasted blondes, attributing the story to Yahoo! News. It also gave them an excuse for using a nice picture to capture the reader's attention, and I take that lesson."

Several versions of the original article state that "American women have the biggest boobs in the world." If this is true, it's only because there are more "artifical ones" here, perhaps. This appears to come under the category of "artificial intelligence," perhaps.

I will venture that my exposure to gifted women at my somewhat "elite" university would easily support that intelligent women are a lot more sexy than the real dummies, but variation in boobishness seemed on a par with the general population. (I really did notice such things way back then.)

John