If global development were a horse race, would you put your money on the slow-and-steady contenders or a fast new contender? With this year's results just in, the old stalwart Scandinavian countries are still in the lead, according to the 2011 United Nations' Human Development Index, published Wednesday.

With Norway leading the charge in this annual assessment of national education, health and income levels, most of the other 186 countries and territories evaluated in this year's report are also on the up and up. The U.S. ranks fourth—with Australia and the Netherlands inching out just ahead.

When the national numbers, based on factors such as life expectancy, poverty and years spent in school, are recalculated to account for internal inequalities, however, the U.S. falls to the 23rd spot—the largest drop of any of the top 85 countries in this analysis.

"The Inequality-adjusted Human Development Index helps us assess better the levels of development for all segments of society, rather than for just the mythical 'average' person," Milorad Kovacevic, the lead statistician for the report, said in a prepared statement. "We consider health and education distribution to be just as important in this equation as income. And the data show great inequalities."

The U.S.'s slide is due primarily to income inequality (a phrase that's now peppering the headlines courtesy of the recent Occupy Wall Street protests nationwide). But, the report suggests, it also took a hit from the uneven distribution of health care.

The U.S. spends 7.1 percent of its gross domestic product (GDP) on health (U.S. public spending on education is 5.5 percent). And although life expectancy is now 78.5 years in the U.S., it is still years off from the corresponding statistics in Australia and the Netherlands, which both have life expectancies of more than 80 years—and spend less of their respective GDPs on health costs.

Development is not, of course, a zero-sum competition. And as the birth of the purported seven billionth person earlier this week has emphasized, rapidly depleting natural resources are a very real concern for the whole globe. According to the authors of the new report, a smarter, more sustainable development strategy tide could raise all ships—and with so many developing nations, such as the Democratic Republic of Congo, where life expectancy is 48.4 years and 73 percent of the population lives in poverty, there are many ships that need a smart development strategy, and fast.

"Sustainability is not exclusively or even primarily an environmental issue," Helen Clark, who chairs the U.N. Development Program, said in a prepared statement. "It is fundamentally about how we choose to live our lives, with an awareness that everything we do has consequences for the seven billion of us here today, as well as for the billions more who will follow."

Charts courtesy of U.N. Human Development Report