In all the public finger-pointing about the American real estate bust, surprisingly little attention has been paid to its origin. There’s obviously a long list of people and ideas that can share in the blame: ratings agencies, mortgage brokers, big Wall Street firms, small Wall Street firms, Angelo Mozilo, Alan Greenspan. Every few weeks, the New York Times runs a piece exposing some new way in which a big Wall Street firm has exploited some poor or middle-class family. The rich people on Wall Street blame their bosses. The brokers at Merrill Lynch blame Stan O’Neal; the traders at Bear Stearns blame Jimmy Cayne. Everyone blames Countrywide. But all of this misses the point: However terrible the sins of the financial markets, they’re merely a reflection of a cultural predisposition. To blame the people who lent the money for the real estate boom is like blaming the crack dealers for creating addicts.

Americans feel a deep urge to live in houses that are bigger than they can afford. This desire cuts so cleanly through the population that it touches just about everyone. It’s the acceptable lust.

Consider, for example, the Garcias. On May 30, the New York Times ran a story about a couple, Lilia and Jesus Garcia, who were behind on their mortgage payments and in danger of losing their homes. The Garcias had a perfectly nice house near Stockton, California, that they bought in 2003 for 160 grand. Given their joint income of $65,000, they could afford to borrow about $160,000 against a home. But then, in 2006, they stumbled upon their dream house. The new property was in Linden, California, and, judging from its picture, had distinctly mansionlike qualities. Its price, $535,000, was a stretch.

Then, of course, the market turned. The Garcias failed to make their mortgage payments and couldn’t sell their original house. They owed the bank about $700,000 and were facing eviction. The mistake supposedly illustrated by the Garcias’ predicament was that they held on to their former home in Stockton as an investment. The moral: Americans are in their current bind because too many of them saw houses as moneymaking opportunities.

But the real moral is that when a middle-class couple buys a house they can’t afford, defaults on their mortgage, and then sits down to explain it to a reporter from the New York Times, they can be confident that he will overlook the reason for their financial distress: the peculiar willingness of Americans to risk it all for a house above their station. People who buy something they cannot afford usually hear a little voice warning them away or prodding them to feel guilty. But when the item in question is a house, all the signals in American life conspire to drown out the little voice. The tax code tells people like the Garcias that while their interest payments are now gargantuan relative to their income, they’re deductible. Their friends tell them how impressed they are—and they mean it. Their family tells them that while theirs is indeed a big house, they have worked hard, and Americans who work hard deserve to own a dream house. Their kids love them for it.

Across America, some version of this drama has become a social norm. As of this spring, one in 11 mortgages was either past due—like Ed McMahon’s $4.8 million jumbo loan on his property—or in foreclosure, like Evander Holyfield’s $10 million Georgia estate. It’s no good pretending that Americans didn’t know they couldn’t afford such properties, or that they were seduced into believing they could afford them by mendacious mortgage brokers or Wall Street traders. If they hadn’t lusted after the bigger house, they never would have met the mortgage brokers in the first place. The money-lending business didn’t create the American desire for unaffordable housing. It simply facilitated it.

It’s this desire we must understand. More than any other possession, houses are what people use to say, “Look how well I’m doing!” Given the financial anxieties and indignities suffered by the American middle class, it’s hardly surprising that a lower-middle-class child who grows up in a small house feels a burning need to acquire a bigger one. The wonder is how an upper-middle-class child who grew up in a big and perfectly enviable house is inexorably drawn to a mansion.

When you move into a house you cannot afford, the first thing you notice is everything that you suddenly need—things that, before you arrived, you didn’t even want. The dressing room was a microcosm of our mansion’s ability to instruct. It wasn’t a closet, but a room as big as the master bedroom we’d left behind in California. Even after my wife had stored her countless pairs of shoes, there was more than enough space for all of my stuff. Three weeks later, I noticed a door near the master-bedroom suite that I hadn’t seen before; it was like a magical door that someone had carved into the wall while I slept. What could it be? I opened it to find…another huge dressing room! Inside, I could have fit every stitch of clothing I owned, three times over. It seemed weird to just leave it empty, but I didn’t have anything left to put in it, so I closed the door and pretended the room wasn’t there. But the thought occurred: Maybe I need more clothes.