The term "child's play" denotes something simple and frivolous. But as Maria W. Piers and Genevieve Millet Landau argue in their new book The Gift of Play (Walker, $9.95), real child's play is serious business, as necessary to children "as breathing, eating and sleeping." A psychologist in the field of child development, Piers, 70, is Distinguished Service Professor at the Erikson Institute for Early Education in Chicago and author of Play and Development, Infanticide and, with Robert Coles, The Wages of Neglect. Landau, 54, is a veteran journalist and editor of three books on psychology. A Phi Beta Kappa at Hobart and William Smith colleges, she earned a master's in English literature at Columbia and joined the staff of Parents' Magazine in 1957, becoming editor-in-chief in 1971. Seven years later Landau resigned to found the Hasbro Center for Child Development and Education in New York, but kept her ties with Piers, who had been a Parents' contributor. Landau and her husband, Sidney, a 63-year-old textiles importer, share a townhouse in Manhattan's Greenwich Village. With the Christmas toy-buying season in full swing, she discussed the misunderstood world of play with Eric Levin of PEOPLE.

Educators, as you point out, often define play as child's "work." Why do you object to this description?

It's an apt image in some ways, but it has been very much misinterpreted, leading parents and teachers to value only those types of play that strike them as prudent, serious and educational. I prefer to think of child's play not as the adult's work world scaled down but as a kind of theatrics. The child is the dramatist, illuminating the events of his inner and outer worlds and thereby mastering them.

Is educational play overrated—such as alphabet toys, teaching games and children's TV like Sesame Street?

For children under 5, very much so. Many parents and teachers try to give preschoolers a kind of academic head start by enrolling them in nursery schools where letters and numbers and reading are taught. But, as a paper presented at Yale last year observed, this approach not only fails to achieve results, it may even discourage and inhibit children significantly. It forces them to jump ahead of their natural timetable.

How?

Imaginative play is the only good and lasting way children learn. This isn't news. In the Republic, written in the fourth century B.C., Plato urged parents to "avoid compulsion and let early education be a sort of amusement. Young children learn by games; compulsory education cannot remain in the soul." In our own time, the late Swiss child psychologist Jean Piaget added, "Every time we teach a child something, we keep him from inventing it himself. On the other hand, that which we allow him to discover for himself will remain with him..."

Why is this so?

If you look at nature, for example, you see that while newborn kittens and puppies play, newborn chickens don't. Why? Animal babies that don't play are ones that are almost ready to be independent at birth. All the chicken has to do is follow its instincts. Animals that do play are learning by discovery and practice the skills they need to survive. Generally, the more intelligent the animal the more prolonged, varied and complex is the play phase. In humans, play is the primary path to learning for the first five years or so.

How does play begin?

In a sense, a baby's own body and his mother's are his first toys. Touching, wiggling, gazing are a baby's first games.

What are the lessons of these first games?

At about 8 weeks of age, the baby gradually learns that his body and his mother's are not the same. By being touched and cuddled, he develops what the psychoanalyst Erik Erikson calls "basic trust." These playful interchanges build the keystone of identity.

What else do children learn through play?

Probably the most remarkable thing is language. A baby's babbling is play; so is the seemingly incoherent speech of toddlers. Psychologist Jerome Bruner has pointed out that acquiring language is "the most complex intellectual feat brought off by the young child" and "it takes place not under the duress of striving for real goals but in playful situations."

How is "make-believe" useful?

Make-believe is nature's own psychotherapy. By acting out frightening situations, children exorcise their own fears. By playing "house" or other role games, they learn about relationships and explore solutions to problems. Having an imaginary friend is a natural and very healthy thing for a child. It develops creativity and identity. Yale psychologist Jerome Singer has found evidence that children who engage in a lot of make-believe play are likely to be less hostile, more sharing, less demanding of adults and more patient than children who don't.

What are the best toys for toddlers?

Simple things that encourage the child to impose his own imagination. Blocks, old-fashioned as they may seem, are ideal. So are simple push and pull toys and little trucks and cars. Common household objects—providing they're safe things like spoons or wooden spools—can be tremendously stimulating, and they have the secondary advantage of referring to the family and the real world. After infancy, costumes and funny hats are great aids to "pretend" play.

Do you favor realistic toys?

For young children realism is of no great value. I don't mean that a model of a gas station can't be emotionally satisfying. But electric and wind-up toys that perform some gimmicky feat simply take initiative out of the child's hands.

What about dolls that are anatomically correct or that cry or wet themselves?

To me, the anatomically correct doll is pious nonsense. The designers are probably just looking for yet another way to create a new product, or maybe they're trying to capitalize on the presumed plus of being "upfront" with kids. Anyway, highly realistic dolls are likely to be seen by small children as grotesque and possibly menacing. A doll that says "I love my mommy," or whatever, is limited to just that. An ordinary doll can do anything the child wants it to. Dolls, by the way, are superb toys for boys as well as for girls, but they should be plush and cuddly, not repellently hard and plastic. A Raggedy Ann doll is hard to beat.

What do you recommend for older children?

Starting at age 6, 7 or 8, girls and boys begin to develop the motor coordination and power of concentration to enjoy things like Tinkertoys, Erector Sets, Lincoln Logs and other construction toys. Chemistry sets can be terrific for older children, if they express an interest in the subject.

What about board games?

I think the games you can play with a simple deck of cards are much more imaginative, but I have nothing against board games. For children who were not able to fully develop their imaginations when they were younger—for whatever reason—board games provide appealing structure while suggesting dramatic scenarios for the imagination to take off on.

Do you object to the new computerized toys and home video games?

I don't think they're evil or dangerous, but it seems to me they promote rather narrow and useless skills and are confining. Kids need more activity than that, anyway. Instead of plugging one of those cartridges into the videotape machine, a family would be better off going for a walk.

What do you think of toy guns?

Though I'm not enamored of them, I don't think they're detrimental. If a child comes from a caring and encouraging home, role-play with guns doesn't promote violence or indicate antisocial impulses lurking under the surface. A badly neglected or abused child, on the other hand, doesn't need a toy gun to harbor destructive thoughts and maybe act them out someday.

Can children have too many toys?

Definitely. And it's not just a question of creating "spoiled brats." Little children get overwhelmed easily; too much stimulation confuses and upsets them. My advice to parents at this time of year, when everybody in the family sends presents to the baby, is to put two-thirds of them away and bring them out individually at appropriate times.

How does TV affect play?

It replaces activity with physical and mental passivity. Heavy TV viewing among preschoolers is surely one of the prime causes for the sorry performance in schools during the past decade. I recommend less than an hour of it a day. Parents should try to watch TV with their kids and have them talk about the show, act out a story based on it or build something they've seen in it.

How else can parents nurture creative play?

Do not fail to read your children a bedtime story or sing them a song, especially if you're out of their lives during the day working. Start the story and let them pitch in. Don't just take them to museums and zoos, but to real work places—lumberyards, factories, markets and your own office. Get involved in neighborhood associations and activities and have the kids take part. This gives them the raw material for play and, even more important, the desire to engage in it.