Linda Pelzman appreciates the beauty of the outdoor world, sometimes pulling her children into the yard to gaze at a full moon or peer into a dense fog. An educator and founder of a summer camp, she only wishes her enthusiasm was fully shared.

On a recent nature walk near her home in Gaithersburg, her younger son, 6, was unimpressed, pleading, "I just want to go back to civilization." Her older son, at 13, has made it clear he prefers PlayStation.