Preschoolers make friends quickly and intensely. To your three-year-old, a "friend" is anyone who is willing to play with her the way she wants to play at the moment. It could be someone she sees every day in the neighborhood or at day care. But it could just as well be someone she meets just once while playing in the park or playground or children's museum. (Even if she never sees that child again, your three-year-old may continue to refer to the child as "my friend.") Your preschooler's friends are just as likely to be boys as girls, because most three-year-olds play with either sex equally well and seldom have a preference for one or the other.
Because your three-year-old probably makes friends quickly, her relationships with other children are not necessarily long-term friendships. Your preschooler may move easily from friend to friend with each passing month (or week). You might hear her say that she has a "best friend," but the identity of this best friend may change monthly (or even daily). Although preserving a long-term special status for one friend comes more frequently at age five or six, your child may nonetheless develop a special relationship with one or two other children. (Holding hands and hugging are common among friends of this age.)
Friendships, no matter how fleeting, are important to preschoolers. Early childhood isolation—whether self-imposed, created by parental inattention, or caused by the rejection of other children—will not only be painful in the present, but may lead to emotional problems in the future as well. So encourage your child to form friendships. Because most three-year-olds make friends so easily, you may not need to do that much to help other than offering her the opportunity to meet other children.
Who Are the People in Your Neighborhood?
At this age, you'd do well to give your preschooler the opportunity to make friends not just with children his own age, but with adults, too—in your presence of course. Your child will feel more comfortable dealing with adults in future situations if he has the chance to become friendly now with parents of friends, friends of parents, teachers, and so on.
It's important for your child to have friends who live in the same neighborhood and this importance will only grow as your child gets older. If your child has friends in the neighborhood, he can visit them on a moment's notice without needing a driver—perhaps without even needing to cross the street.
So if other preschoolers live in your neighborhood, try to begin with them. Try to find other kids who are roughly the same age as your child. Get to know the parents of other preschoolers in your neighborhood and then arrange some playdates or special outings that will bring your child and other three- or four-year-olds together. (Playdates will also give you the opportunity to spend time and share experiences with other adults.)