Among American adults who say they may not participate in the 2010 Census, 44% are under age 30, according to a new analysis of a Pew Research Center survey on attitudes toward the national headcount.

The survey, released last week, found that most Americans are aware of the 2010 Census, and 87% say they definitely or probably will return their forms. But 12% of American adults say they might or might not participate, probably will  not participate or definitely will not participate by filling out their 2010 Census forms. This new analysis looks in detail at this skeptical group, which poses a challenge to the Census Bureau’s efforts to achieve a complete count.