Here's a nice, tasteful question for you... 
I saw the other thread asking about the value of people's wedding, engagement and eternity rings, and it got me thinking that quite often I notice big diamonds on American and, to a lesser extent, Australian women, but not so much on English, European and Scandinavian women. The people I am thinking of are all high earners (or married to), so its not to do with money. I am assuming its to do with taste/preference?