In China they're called Little Emperors. In Europe they've been blamed for the population decline. And in certain corners of the United States, they're considered tragic -- even vaguely unpatriotic.

Only children, and the parents who bring them into the world, have historically been viewed with suspicion. In the past, when a family's survival depended on the number of hands available to plant and harvest food, big families were prized. While that's still the case in certain parts of the globe, technological advances for the most part have eliminated the need for (and the inevitability of) multichild families.

Still, demographers tell us that the majority of Americans, given the choice, would have more than one child. Single-child families have nearly doubled in the United States over the past 15 years. (See chart, p. 14) Yet despite this startling increase in only children, the negative stereotype of the spoiled, maladjusted loner continues.

Bill McKibben, environmentalist, author, and father of a 4-year-old daughter, debunks these prejudices in his new book Maybe One: A Personal and Environmental Argument for Single-Child Families (Simon & Schuster). For personal and environmental reasons McKibben and his wife, writer Sue Halpern, were inclined to have just one child. But like many parents, they worried about the emotional and social repercussions. McKibben did some research to answer his own personal questions and came away assured that single-child families don't harm kids. (Indeed, dozens of studies point to the fact that only kids actually fare better in measures of achievement motivation and social adjustment.)

In addition, McKibben concludes that families stopping at one kid may be the best -- and only -- way to counteract a world population explosion that is spiraling out of control. While certain industrialized countries - among them Japan, Spain, and Italy -- are seeing negative population growth due to dramatically shrinking family size, McKibben notes that global population continues to boom. More American women, for instance, may be having just one child, but the population base from which these single-child families spring is so large (and the percentage of only children still so small) that at current rates, the number of people in our country alone will double by the year 2050, creating greater pressure on the earth's natural resources.