"I was a little disappointed," Andersen confesses. "I had believed, just like everybody else, that money was the problem." But he soon began to see money as one of many factors—along with issues like sex and in-laws—that contribute to a "stress threshold," above which divorce tends to occur. "We do know that couples fight about money, and I think if we get them to handle it better, we could reduce the level of stress," Andersen says. But ultimately, he concludes, "Money may just be a mask." Many therapists agree.

Lois Gold, for instance, has particular insight into why people split up. She not only coaches couples still struggling to make their relationships work, but is also a licensed therapist and divorce mediator (which means she can facilitate a divorce, lightening the load of family courts and hopefully making the process less ugly). Over the past 25 years, Gold has handled more than 1,200 mediations between spouses who are certain their troubles can't be fixed, and has written a book called Between Love & Hate: A Guide To Civilized Divorce.

"Money can be a vehicle for other kinds of conflict and other kinds of hurt," she explains. "For example, a person who's angry about sex might withhold money."

Financial issues can also play out more subtly. "I once worked with a couple who'd agreed that the wife would stay home until the kids went to school, and then she'd start earning again," Gold remembers. But the woman procrastinated, and the husband grew resentful. Over the years, the wife lost confidence about measuring up in the workplace, and the husband interpreted her fears as not wanting to help him out with expenses. "He got so angry after a while that the first thing he did when he came home every day was to inquire about what job hunting she'd done," says Gold. "The pressure only made her feel worse about herself, and the situation undid the relationship."

Of course, there's no psychology without family, and many financial conflicts arise from issues that long pre-date the honeymoon. For instance, inheritances can challenge the strongest relationships.

Take Lisa K., whose lover's wealthy family used money as a means of control. Horrified that their daughter was involved with another woman, Lisa's partner's parents stopped sending checks. After five years of real devotion, the romance finally collapsed under the family assault. Lisa's partner went straight home—then to Switzerland, Iceland, Chile, and finally to a realtor who found her a condo in Washington, DC. "I just thought she was a regular person who didn't have student loans," Lisa says. With time, though, she learned that her ex belonged to a family that expressed emotions like a bunch of bank clerks. "She really is honorable, but there’s this thing about wealth," muses Lisa. "I never met people who wanted to be rich so much."

In short, money is never just an amount—it's a symbol, a fetish, a tool. "She wanted their love," Lisa says of the ex and her family, "and they leveraged their love with money."