This is from a Feb 6th Wall Street Journal article about the importance of asking certain questions before one gets married. Here's one that jumped out:
"Among the most telling questions: Would you ever consider trading in your engagement ring for a bigger, better diamond? In a 1988 poll of 200 new brides by Diamond Cutters Intl, 46% said yes and 54% said no.
...15 years later the same women were surveyed again. Of those in 1988 who were willing to trade up their rings, 81% are now divorced. Of the sentimental types who said they'd never trade their rings, 78% remain married.
...the results suggest those who are "hard wired" to upgrade rings also may be driven to upgrade cars, houses and eventually, spouses, says psychiatrist Francisco Montalvo, who monitored the study."
You can always quibble over statistics, but to me, 15 years seems like a good length of time and the percentages are pretty impressive.
