Jane Haller overhears this conversation between her 3-year-old twin boys one day: "I need to fix my car," Ray says. "I need to go to work. My beep is broken."

"Let me see the beep," Dan replies. "Oh, it's kind of beepy. Let me see the wheel. I'll check the other wheel."

As their pretend play continues, the boys talk about hammers and saws, concluding they'll use a saw for the job of fixing the "broken beep" because, well, they don't have a hammer.

For those few moments, as their mother watches from nearby, Ray and Dan are in their own world. Sure, their playtime isn't without its typical childhood mishaps – one wanting something the other has, one bopping the other over the head – but their parents are happy to see they often work together and truly enjoy each other's company.

"They play together really well," says Haller, of Columbia, Ill. "Right now, they're getting into different kinds of role play."

It's often said that a twin or triplet grows up with built-in playmates, but each child's temperament, abilities and interests determine how well multiples interact. While child development experts and parents of multiples say you can't force the friendship, you can still influence positive, cooperative play.

The Art of Cooperative Play
"They are almost always in the same geographical space, and they're going to be in each other's company for a long time,” says Judith Wagner, professor of child development and education at Whittier College in Whittier, Calif., and the mother of twin girls, now grown and each the mother of infant twins herself. “Therefore, it's really important for twins to learn to be together peacefully and cooperatively."

Multiples typically develop the art of cooperative play faster than singleton babies. "Twins are born interacting and their play is richly developed with one another, even pre-verbally," says Patricia Malmstrom, a Berkeley, Calif., mother of twins and the author of The Art of Parenting Twins (1999, Ballantine).

Still, remembering that twins or triplets are individuals is important when engaging them in play, says Maureen O'Brien, Ph.D., a developmental psychologist who teaches at Bentley College in Waltham, Mass., and the mother of 8-year-old twin boys.

"Try to bring them together every once in awhile, but just because they're twins or triplets doesn't mean they want to do the same things," she says. "Parents have to put the brake on their own expectations."

Activities and Toys That Work
Blocks, Legos, Play-Doh, coloring tools and toys that have numerous parts are popular choices for multiples, experts say. With these, toddler twins and triplets can play side by side and not necessarily bicker because there's plenty to go around.

Activities that feature multiple characters, such as a game of dress-up in Mommy's or Daddy's clothes and shoes, a puppet show using stuffed animals or a rendition of Ring-Around-the-Rosy also are good ways of encouraging cooperative play.

Parents can suggest such activities, but usually play is most successful when the children come up with an idea themselves. Haller found this to be the case with Ray and Dan, who have been known to act out situations and people they know using their trains and trucks.

"I'd always seen the boys play with trucks and trains and wondered how it could be interesting for so long," Haller says. "But they were using the trucks to play out social situations: ‘Here's the mommy truck, here's the daddy truck, and they're going here.’ The trucks have personalities. They like to pretend to be people they know, like family members or the next door neighbor's grandkids."

Briggen Wrinkle's 2-year-old twins, a boy named Corbin and a girl named Carter, entertain each other during grocery store trips. With one on her back and the other in the shopping cart, "They tend to talk the whole time, laugh and look around the store,” says the Chicago mom. “I'm totally left out."

Certain activities – cleaning up toys, bath time and getting ready for bed – are times when Wrinkle says her twins work especially well together. As they read books at night, for example, they'll settle quietly on the floor and not necessarily fight for Mom's or Dad's lap, she says. Also, one sibling might make the gesture of getting a pacifier for the other.

Modeling positive partnerships is important, adds Wrinkle, who tries to do this with her husband, John.

"I think more than anything, if you're lucky enough to have a partner or at least two adults in the household, you should interact well together," she says. "John and I play with the kids, but we'll play with each other in the same room so the kids see that. We really try to lead by example."

Quantity of Toys
Tempting as it may be, parents of multiples should avoid buying two or three of a toy to appease their twins or triplets, experts say. Not only does this lead to massive amounts of toys, it also doesn't prevent fighting over objects, because like all kids, multiples will probably want what their sibling has. The competition, in fact, could even be greater among multiples, Wagner says.

Providing toys that are similar yet different is the answer, say parents and experts.

"If you're going to get three trucks for triplets, get three different trucks and hope something stands out," Wagner says.

O'Brien says she's seen her own twins benefit from this approach, which she began early on. Now, her sons Alex and Matthew understand the importance of sharing and working together to solve issues and problems.

"Learning to take turns and to see from the other kid's perspective occur during playtime while a child is in the age range of 1 year to 3 years,” says O'Brien, who also authored the book Watch Me Grow: I'm Two (William Morrow & Co., 2001) and Watch Me Grow: I'm Three (Perennial Currents, 2002). “It's the adult's job to structure some of their play so they can build up those skills."

At the same time, parents need to provide enough toys, and even some that are specifically one child's, so the children have a sense of ownership.

"I can't stress enough having a sense of owning toys," says Malmstrom, who is the founder and president of Twin Services Inc., also known as TWINLINE, a national resource helping parents cope with "twinshock." "They will barter and trade and carry on and forbid the other to touch their toy. But they have a sense of 'this is me.'"

Wagner refers to this critical way of thinking as a "healthy sense of entitlement." This leads to having the ability and desire to share.

Seeing her twins grow in their friendship with each other is a good feeling, Haller adds. "I've just tried to get them to always be kind to each other no matter what," she says.

This seems to be working well. While there are plenty of trying moments, there also are wonderful times when the boys seem to just click, she says.

Haller recalls a memory of her twins eating together at 6 months of age: "I have a picture of them at that age, sitting in their high chairs, laughing at each other," she says. "One brother is leaning over with his hand on the other's shoulder. It looks like two old guys at a coffee shop."

Want to see more?

• Two Peas in a Pod? Ten Ways to Encourage Individuality in Twin Toddlers
• Can Parents Influence Personality Traits?
• Choosing Friends: An Experience in Social Development
• Recommended Reading List
• Double Trouble: Twins and the Terrible Twos
• Talk about it!