I always know when it's Tuesday. On that morning my 3-year-old son, Luke, hears a beeping noise and shouts, "The garbage truck is here!" and races to the window to watch the action. That's just one example of his tunnel vision when it comes to trucks. On the way to preschool we pass a construction site, and Luke begs, "Put down the window, Mommy." At night he snuggles into sheets dotted with backhoes and diggers as I read a bedtime story that invariably has a moving vehicle of some sort in the title.
I'm far from the only parent whose child has developed a fixation. Researchers estimate that 70 percent of preschoolers have had a consuming interest. For moms and dads who are dealing with a Cinderella groupie or dinosaur devotee, it's hard not to wonder where these obsessions come from and what they might predict about the future. Before you decide to buy another set of baseball cards or hide all the Polly Pockets, hear what the experts have to say about little kids' intense interests.