On a beautiful summer day in 1899, the fabulously wealthy Alva Vanderbilt Belmont sponsored a "motor carriage" parade on the lawn of her "cottage" in Newport, Rhode Island. The festivities included an obstacle course of dummy policemen, nursemaids and babies in carriages, with a prize going to the driver who "killed" the fewest of these innocent bystanders. Alva's son Willie K. went on to sponsor the first major trophy in American auto racing. (And at an early Vanderbilt Cup race, an innocent bystander was killed for real.)

So let's add auto racing to the long list of great ideas brought to you by what Canadian archaeologist Brian Hayden calls "triple-A" self-aggrandizers—people who are aggressive, acquisitive and ambitious about getting what they want. Hayden acknowledges that other words starting with "a" may also come to mind. Arrogant, say. Or even alarming.

But let's just call them rich.

In our hearts, we like to think that all the great ideas and inventions have come from salt-of-the-earth, self-made men and women. But students of "affluenza," the social condition of being rich and wanting to be richer, have lately come to credit rich people as the driving force behind almost every great advance in civilization, from the agricultural revolution to the indoor toilet.

This is of course a disconcerting idea, even for the researchers who have proposed it. And plenty of other researchers say they are wrong. But before we crank up our moral dudgeon, we should know that the rich in question are almost certainly family. Like it or not, we are probably descended from them, according to Michigan anthropologist Laura Betzig.

High status has almost always translated into reproductive success, not just in the animal world, but for humans, too. This phenomenon started back in our hunter-gatherer days, when the men who brought home the most meat won the most mates, and it has continued up through the likes of J. Paul Getty and Donald Trump. Betzig's research piled up historical examples, including extreme cases such as the Aztec strongman Montezuma, said to have kept 4,000 concubines, and a Chinese emperor whose harem numbered in the tens of thousands. On a lesser scale, the big houses of the British countryside before World War I often accommodated 10 to 20 servants, who were typically young, female and single. "Housemaid Heights," Betzig argues, functioned as a de facto harem for upper-class males. Thus an 1883 investigation in Scotland found that domestic servants accounted for almost half of out-of-wedlock births.

Other researchers have noted the baby-making propensities of alpha males among the Ache Indians of Paraguay and Venezuela's Yanomami. One found that the pinstriped chieftains on the 1982 Forbes 400 list of the richest Americans were out-reproducing their fellow citizens by as much as 38 percent.

But what difference does that make?

Not much, it seemed to Gregory Clark when he was first thinking about why the Industrial Revolution started in Britain, rather than in China, say, or India. Clark, an economist at the University of California at Davis, knew that in the past, British cities had an appalling mortality rate and prospered only by consuming a large annual crop of newcomers from the countryside. So he assumed that modern British people were, as he put it in a recent interview, "the remnants of rural idiocy"—that is, descended from less energetic, less educated types who stayed put on their farms. (The assumption was perhaps a byproduct of Clark's having grown up in an Irish Catholic family in Scotland, a pedigree unlikely to produce either Anglophilia or an admirer of the rich.) But his opinion changed when he undertook a detailed analysis of 3,500 British wills from 1250 to 1650, looking particularly at wealth and reproduction.

"To my surprise, there was a very powerful effect," says Clark. "The wealthy had many more children." He wasn't looking at the aristocracy, who tended to get killed in wars and power struggles (or to wane because of reproductive ennui). Instead, he looked at the enterprising gentry, people a notch or two down the social hierarchy, who devoted their lives to commerce and died in bed. "They had four surviving children in a society where the average was two," Clark says.

Other researchers have argued that the Industrial Revolution got started, in Britain in the 18th century, on the strength of coal and colonies. But in his new book, A Farewell to Alms, Clark proposes that what really made the difference was this "survival of the richest." In the relatively stable British climate after 1200, with limited resources and little population growth, "the superabundant children of the rich" inevitably moved down the economic ladder, displacing poor families. And something of their privileged past went with them. "The attributes that would ensure later economic dynamism—patience, hard work, ingenuity, innovativeness, education—were thus spreading biologically throughout the population," Clark writes.

This change may well have been "completely cultural," Clark says. But he is clearly more interested in the possibility that Darwinian evolution—with disease, accidents and starvation driving less successful families onto the scrapheap of history—produced a genetic change in the British people, preparing them better than those of other nations for commercial success.

He readily acknowledges that the idea is fraught with difficulty. A faculty petition had just prompted his university to disinvite a scheduled speaker, economist and former Harvard president Larry Summers, because of Summers' profoundly controversial 2005 suggestion of a genetic difference in science aptitude between men and women. This all makes Clark uneasy, he says, because his book "suggests that there might be a genetic difference between Europeans and Australian aboriginals." Then he adds: "Not that Europeans are smarter, just that they may be better adapted to a capitalist society."

An adaptation that particularly interests Clark has to do with "time preference," which can take the form of patience and long-term planning in some people and an impulsive urge for immediate gratification in others. When forms of such a trait already exist in a population, Clark says, natural selection could rapidly make one form predominant, just as blue eyes or fair skin can come to predominate. Thus the surplus reproduction of the rich may have turned England into the birthplace of industrial manufacturing by replacing impulsive traits with the slow and steady. "It may just be the drudges that have been left," Clark says. (Maybe that's why the British became known as a "nation of shopkeepers.")

But why didn't the same kind of evolution take place in other countries? In China and Japan, the rich seem not to have been so fertile, Clark writes. (The historical data for India doesn't exist, as far as he knows.) Moreover, the population in China tripled in the centuries before the Industrial Revolution, and in Japan it quintupled. So natural selection may not have been killing off the poor quite so remorselessly as in Britain, where the size of the population remained the same.

Other scholars have praised the detailed research and ambitious scope of Clark's work. But they have also questioned whether genetic, or even cultural, transmission of behavioral traits from rich ancestors is enough to explain the Industrial Revolution. Economists still generally argue that good institutions are the primary factor in such big leaps forward, because they make people feel sufficiently secure to focus patiently on long-term gain. And recent evidence suggests that when institutions change, as they have in China, Japan and India, people there seem quite capable of adapting to capitalism.

There is, however, another way the rich may have helped make us who we are: by their knack for "extreme selfishness." Like many scholars, Brian Hayden, an archaeologist at Simon Fraser University in British Columbia, believed that leaders generally served the common good. Then he interviewed people in traditional Mayan villages about how their leaders had helped out during droughts and famines.

"I was completely blown away by the results," he recalled recently. "Instead of helping the community, people in power took advantage to sell food at exorbitant prices, or they hoarded food and wouldn't share it, or they used food in trade to take over land." In the ethnographic literature on traditional societies around the world, Hayden found frequent accounts of despots and psychopaths—leaders who took what they wanted even when it meant disaster for their neighbors. He came to think that the rich and powerful—his triple-A types—played a dual role in society. On one hand, they bent laws, exploited neighbors, seized every little advantage. On the other, their gaudy pursuit of status also made them role models who produced, or served as patrons for, all kinds of shiny new inventions.

Hayden's research focused on how "big men" in early cultures used feasts to build political alliances, arrange marriages or simply make lavish displays of wealth. Some feasts obliged rival leaders to return the honor—and generally one-up it. Other archaeologists regard the proliferation of feasts 10,000 or 12,000 years ago as a byproduct of the first successful attempts at domesticating crops. But Hayden argues that feasts may actually have caused the agricultural revolution. As in high society today, a brutally competitive round of feasts forced desperate hosts to seek ever fancier new foods and drinks—not only staples, but also delicacies. So they may have domesticated wheat not for bread, but for beer. They domesticated status foods, such as the chili pepper and the avocado. (Think guacamole.) They cultivated chocolate for the Mesoamerican rich.

Melinda Zeder, a specialist in the origins of agriculture at the Smithsonian National Museum of Natural History, dismisses this as the "food-fight theory." The idea that competitive feasting led to the domestication of plants and animals "doesn't work," she says. "It's wrong from beginning to end. It does not jibe with the archaeological record." Hayden counters that there is archaeological evidence for his ideas. Moreover, he says his emphasis on the importance of hierarchy makes perfect sense to people who have lived with triple-A types in traditional cultures. Only academics who believe in the egalitarian character of traditional societies "don't get it," he says. "They think it has to be for the common good."

Even if crediting the rich with the agricultural revolution seems like a stretch, Hayden has marshaled plenty of other evidence that triple-A types have repeatedly driven the development of new technologies for the purpose of displaying their prestige—textiles, for instance, and metalworking, glass, indoor plumbing and illuminated books. Then the sweaty mob imitates them, gradually figuring out how to make prestige items more cheaply and put them to practical use.

This may sound like trickledown theory revisited. Or like a new take on social Darwinism, the 19th-century idea that the strong somehow end up smarter, fitter, more deserving—and richer. But the new affluenza theorists say that they're just explaining the way things work, not defending it. Hayden concludes that the status-grabbing, triple-A aggrandizers have created the world as we know it. But in their other lives as pirates, these same people have caused "90 percent of the world's problems" with a casual tendency to "ruin the lives of others, erode society and culture, and degrade the environment."

If he's right, the moral of the story might go something like this: the next time you come face to face with the rich and powerful among us, do the right thing and say, "Thanks for the secondhand status symbols." Then run as fast as you can in the opposite direction.

Richard Conniff, a longtime contributor, is the author of The Natural History of the Rich: A Field Guide.