I have a ten-month-old daughter named Lucy, and over the weekend I watched her try to do something new: make friends.

We were at the home of a friend whose four-year-old daughter was racing around and having great fun with her three-year-old cousin.

Lucy couldn't keep her eyes off the older girls, but she wasn't able to figure out how to take part in their play until she crawled under a card table that had a distinct "fort" air about it. The other little girls joined Lucy, who started grinning with pleasure.

All too soon, the girls crawled out, leaving Lucy alone. Sure, Lucy is a little young for friends who can run around and shriek real words. She's even too young to play with kids her own age, although other babies fascinate her and she loves to be near them. I know these things intellectually, from all the books and articles on child development I've read.

Yet all that knowledge didn't stop my heart from breaking just a bit to see her delight fade so quickly when the girls ditched her.

My brother-in-law told me to get used to this feeling. Part of the agony of parenthood is watching our children try to make friends with others, and either succeed or fail. You instinctively dislike seeing your child get rejected.

This instinct serves a good purpose. It turns out that the ability to make friends is critical for the success of our children, even early on. And it's not just because friends make our children smile and laugh. Friends may also help kids do better in school because so much of their learning comes from interaction with others, according to a 1998 study from the University of Illinois at Urbana-Champaign. And kids who feel connected in school will be happier getting on the bus in the morning.

What's a parent's job in this, other than to get a stomachache every time our children venture onto the playground in search of friends?

We can do a lot to help our kids succeed socially. It helps to know a bit of background information, such as the role friends play in our children's lives, when kids are ready to make friends, the basic friendship skills we need to instill, and some troubleshooting tips to assess whether our kids are having trouble.