Wedding rings are just a symbol, but ...

So, why do we care about when, or if, stars are wearing their wedding rings? The answer is simple, says Howard Markman, co-director of the Center for Marital and Family Studies at the University of Denver.

"We need to have celebrities providing the positive message that marriage matters and that they're taking marriage seriously to the extent that they are role models," Markman says. "With young people, who might be particularly influenced by messages about marriage, we have a culture where more than ever people dream about a happy marriage, but they are less confident that it will happen to them."

Seeing stars wear their rings shows that they're open about the status of their relationship. But that doesn't mean — rings or not — that celebrities are the paradigm for stability and long-term commitment.

Many stars "live their life as if marriage is as important as buying a car," Markman says. There are obviously some exceptions, but if you just chart the marriage and divorce rate of celebrities, you'll see that their marriage rate is higher than average and their divorce rate is much higher than average."

Ultimately, Markman says, wedding rings are just a symbol. "Wearing a wedding ring does not protect people against divorce. Couples get married today and wear a wedding ring, but 45% of them are going to get divorced. So, the wedding ring on and off really doesn't matter. What really matters is the commitment that people have to their relationship."