Some children prefer certain playmates from very early on, but can we call this friendship? Experts show how toddlers and preschoolers learn and benefit from early friendships.

From the time he could say their names, my son talked continuously about two of the children in his family-style childcare. They were both older, nearly three as compared to his 18 months. By the end of the year he had merged their names into one from frequent use. My son seemed more subdued on the days when one of them was sick, and he gave each of them a hug when they arrived in the morning. Of course I called them his friends.

But do toddlers really have friendships? Do they wrap their minds around relationships in the same way older children and adults do? Not exactly, experts say.

It's popular among parents to believe that six-month-olds in a playgroup are having fun with their "friends," says Dr. Sarghi Sharma, MD, assistant professor at the University of Texas Medical Branch at Galveston. These youngsters can engage with each other to some extent, but they are not interested in each other in the same way that adult friends are.

Give-and-take, cooperative friendship does not generally exist until around age three, according to the child psychologists, pediatricians and childcare providers interviewed. But children can and do express preferences for other kids long before then.

Before they are able to confide in a friend at age three or four, children often seek the company of like-minded others. Yet it is not always clear why certain children gravitate toward each other. Factors that attract kids to each other might include size, familiarity, character traits, or even the shapes of their faces—but no one is quite sure.

"It's always fun to watch children when they're in a childcare setting, and the teacher will say, 'Those two are lovebirds,' and you just don't know why," says Judy Joynt, infant and toddler faculty member at the Center for Montessori Teacher Education in White Plains, New York. Children are able to connect this way once they can walk with their hands free. To show their affection, according to Joynt, the children might hold hands, hug each other, sit side-by-side at lunch, or pass toys back and forth.

"Preferences for familiar peers" have shown up by the age of 12 months among children who are cared for together, says Dr. Dale Hay, PhD, professor in the School of Psychology at Cardiff University in Wales. These interactions can provide "a firm foundation" for future friendship.

But keep in mind that no one is born with a blank slate, says Dr. Charles Goodstein, MD, psychoanalyst and professor of psychiatry at the NYU School of Medicine. Humans are born with the beginnings of character traits that develop over the years, according to Goodstein, and toddlers might express preferences based on level of aggression or activity.

"Earlier on, children are going to select other playmates more by temperament and disposition" as well as proximity, says Dr. Gordon Caras, PhD, an adult, child and adolescent psychologist and psychoanalyst in Solana Beach, California. "Some children who are more responsive to being overstimulated are going to shy away from the children who are more active."

Parallel play, in which children play near each other but independently, often happens among toddlers of similar ages and abilities. And sometimes a sweet companionship arises between children who are a year or so apart in age, creating a motherly or nurturing relationship, Joynt says.

"It's actually probably the best of both worlds, because the younger child is very eager to explore and to learn, and the older child is setting some modeling behaviors," says Dr. Sharma, adding that at the same time, the older child enjoys showing mastery and setting the pace.

While relationships with other children can be interesting for infants and toddlers, the important adults in their lives far overshadow everyone else.

"Other children really are very secondary, and that includes siblings as well as same-age peers," Dr. Goodstein says. "In fact, the parent is such a dominant component in a young child's life that other children are almost an afterthought, I would say."

Infants and early toddlers are highly self-centered creatures, and Dr. Caras says, "They're a bundle of impulses and urges." Slowly these little ones begin to interact more with the world of others. The following are examples of social milestones they'll experience:

• At 16 to 18 months, children might begin to play next to peers.
  
   
• At 19 to 21 months toddlers can start to have a "sense of self," according to Dr. Caras, and often become more possessive of toys.
  
   
• From about 22 to 25 months, children understand themselves as separate people and start to use language to solve their problems, but they still do not engage in cooperative play.
  
   
• At approximately 30 months, children start to play with others in bits and pieces—it's not simply parallel play anymore.
  
   
• Finally, around age three, children are fully ready for cooperative play, says Dr. Caras, and caregivers should encourage "plenty of playmates" to foster the beginnings of true friendships.

Parents can promote relationship skills in many ways. Often the best example comes from the parents forming secure attachments to their children and being friendly with others.

Playgroups and childcare settings are especially good for socializing toddlers and older infants. Such experiences "are instrumental in the development of the awareness that others have needs and wants," Joynt says. "They are learning empathy and becoming socially acceptable beings."

Spending time with other children also helps kids develop reasonable responses to frustration, such as using language instead of throwing a tantrum, according to Dr. Caras.

Imaginative play is another way of encouraging kids' ability to play with others. "Parents need to be able to…go a little bit into the play world with the child, have that door open," Dr. Sharma urges. "Encourage the fantasies, and don't say, 'That's not real, that's not how things happen.'" When two-year-olds pretend they are riding a rocket to the moon or concoct a conversation between two stuffed animals, they are building foundations for empathy and cooperation. Reading books and telling stories have a similar effect.

One of the most fascinating and difficult aspects of studying relationships among young children is that adults cannot tell exactly how these little kids feel.

"Friendship is a pretty complicated business," says Dr. Goodstein. "We're talking about kids who cannot truly discuss their inner lives or inner feelings."

As a result, some researchers are aiming to jump inside children's minds in new ways.

Sarah-Louise Moore, research assistant to Dr. Hay, says that most experiments on three-year-olds' understanding of friendship have been heavily based on asking children questions: "For example, if you ask a toddler, 'Why are you Jack's friend?' he or she will often reply, 'Because I am.'"

However, in a 2004 study by Moore that used puppets, flashcards, and an illustrated book, three-year-olds demonstrated a more complex understanding of the affection underlying friendship, even giving ideas for how "fictional characters could make friends again after an argument," according to Moore.

Such creative methods of investigating relationships could eventually lead to the discovery of reciprocal friendship in children younger than three, Moore says—giving us a new perspective into toddlers' ever-changing minds and budding friendships.