What children learn from collecting.

Your child's rock collection may just look like a pile of stones to you. But it's doing more than gathering dust. "When a child collects things, it teaches them important skills that they'll use throughout their life, including how to organize and interact with others," says Desmond Kelly, a developmental-behavioral pediatrician at All Kinds of Minds in Chapel Hill, North Carolina. The institute, affiliated with the University of North Carolina, is dedicated to studying how people learn.

Here's a look at what children who collect gather along the way:

Personal responsibility. When it comes to a child's prized collection, you're likely to see some impressive "care and feeding." Kids often become interested in collecting around age 5, with many becoming completely intrigued with a particular collectible — be it seashells or stickers — between ages 6 and 8. It's pretty common for kids to spend hours arranging their collection and reading about the items, as well as talking about them with friends and family.

A knack for organization. Any zookeeper will tell you: If you've got a herd, gaggle, or troop of animals to house, you've got a lot of organizing to do. And that goes for the stuffed species as well. That heap of plush puppies and fluffy kittens sitting atop your child's bed got there because somewhere along the way they decided: Okay, I'm putting all the dogs and cats on the bed. That stuffed iguana that Grandma gave them? It might end up on a desk all by itself because, well, it doesn't quite fit in with the other animals. So not only are they organizing, their categorizing.

Mathematical smarts. Whether your child is collecting baseball cards or rocks, it's a pretty good bet that they know the exact number in their collection. They may spend a lot of time grouping them into various categories: years and teams or sizes and shapes. This requires counting, tabulating, and sorting.

Reading skills: A child with a passion for dinosaurs who collects plastic models will also want to know when Tyrannosaurus rex roamed the earth, and whether T. rex was a carnivore or an herbivore. And that means trips to the library and to the museum bookstore.

Social skills. While your child is negotiating a card trade or informing a classmate about the new addition to their dinosaur collection, their inspired to interact with other children. A collection can be a great way to boost self-esteem, as well as serve as a smooth entry into friendships. If your child is new to a school or neighborhood, discussing their trading card collecting can be a great ice-breaker. Meeting kids who share a similar interest could mean they also found new buddies.

Budgeting skills. "Collectibles are a great way for kids to learn how to manage money," says Janet Bodnar, executive editor of Kiplinger's Personal Finance magazine and author of Dollars & Sense for Kids. "If children are expected to pay for collectibles out of their allowance, they have to make decisions about how much they're going to spend — they're learning how to budget."

Collecting is also all about fun and play, so if your child doesn't show an interest, don't force it. For kids who do enjoy collecting, it's a good idea to let your child figure out on their own how they're going to "play" the collecting game — of course, parents should still make a point to show they care. Casually asking about their organizing scheme with a question such as, "I see you've divided up all your Barbies' clothes into different shoe boxes. How'd you decide which outfits to put in each box?" By describing their reasoning, they reinforce the learning they've done all by themself.