Incredible shrinking US family

The Disney-released movie "The Incredibles" depicts a family of five in which each member has extraordinary powers. What the script leaves unsaid is that they are unusual for something more than Dad's super-strength: their family size.

Newly released Census Bureau figures emphasize that over the last decades of the 20th century, the size of US families has shrunk - dare we say it? - incredibly fast. Since 1970 the percentage of households containing five or more people has fallen by half.

Meanwhile, the number of single and two-person households has soared. One demographic group that has increased particularly fast: single women between the age of 30 and 35.

Thus, as the Economist magazine has pointed out, the movie that might best represent this era is "Bridget Jones," depicting a famously single and young (well, youngish) heroine. "It's clear from [the new Census figures] that compared to the middle of the 20th century, marriage is not nearly a universal status of adulthood," says Barbara Whitehead, codirector of the National Marriage Project at Rutgers University. "There is much more diversity in living arrangements."

This doesn't mean that Disney isn't aware of the nature of its target audience. In recent years, its films have depicted a number of untraditional family groups. There's "Finding Nemo," based on a widowed father living with his son. And what could be more au courant than "Toy Story," in which a diverse group of playthings live together in a kind of plastic commune?

But the model of three children living with both their natural parents, or, indeed, the model of five people living together at all, is somewhat retro today, taking overall statistics into account. In 1970, 21 percent of households had five or more people, according to a newly released Census analysis. Today it has dropped to 10 percent.

During that same time period, the share of households with one or two people increased from 46 percent to 60 percent. Overall, the average number of people per household decreased from 3.14 to 2.57. "Households have decreased in size, with the most profound changes occurring at the extremes, the largest and smallest households," concludes the Census report on America's families and living arrangements.

(Sponges living by themselves in a pineapple were statistically insignificant and thus were not included in the Census figures. That would be "SpongeBob SquarePants," a Nickelodeon production.)

Still, the Census did note that the proportion of young, never-married singles has increased dramatically in the US. That's particularly true for women of a certain age. The number of households consisting of single women 30 to 34 has tripled since 1970. "The demographic trends that we are seeing are really quite dramatic, and are creating what I see as backlash," says Bella DePaulo, a psychologist at the University of California at Santa Barbara.

Ms. DePaulo sees a gap between the nation's actual demographics and the way society is reflected on TV, in advertisements, and so forth. "There is this relentless glorification of marriage and coupling at a time in the nation's history when marriage has never been less important," says DePaulo.

The reduced fertility behind the drop in family size is the result of many factors, among them the increase in the percentage of women who work and the rising expense of raising children in today's society. The norms of parenthood are simply different now, says Ms. Whitehead. Parents are more concerned with putting effort into the raising of each child, by guiding them through the right schools and other efforts.

Unlike European societies, the US has limited government support for families, in the sense of subsidized child care or job-protection rights. Thus big families run by stay-at-home moms may be becoming the province of the upper classes, who can afford them. "You can juggle one child, or possibly two, but how can you work and adequately care for four, five, six children?" says Whitehead.

And it's mothers who are doing the juggling. The US has an estimated 5.5 million stay-at-home parents, according to a new analysis by the Census Bureau. Of these, 5.4 million are women.

The Census Bureau judges that there are only 98,000 true stay-at-home dads in the whole country, despite the number of cinematic depictions of fathers who lose their jobs and find happiness ferrying kids to school and constructing art out of toilet-paper rolls.

Given all this, singles may feel it's time to flex their muscles, culturally speaking. Why not a National Singles Day? That's the suggestion of Thomas Coleman, executive director of Unmarried America.

"A lot of single people feel shortchanged, especially when some of their friends have already had a wedding, or two weddings, and baby showers," he says.

Disney take note. Perhaps a follow-up: "The Incredible," as in only one.