Q. We are trying to make kindergarten plans for our 3-year-old -- the middle son -- and we have to decide now, so we'll know whether to send him to nursery school or pre-K in September.

Should we hold him back a year, so he won't start kindergarten right on the heels of his brother? If we do, he'll go back to his three-day nursery school for a year, and then on to a five-day pre-K program. Will this challenge him enough? Although he's good at solving his own problems -- including boredom -- the curriculum may seem pretty tedious by then, even if he goes from 9 to 3.

Although I frequently introduce new things for them to use, give them many books, games and puzzles and my husband and I read to them often, I don't want to play teacher at home, day in and day out, to keep him entertained.

My husband, however, thinks the delay will help him compensate for his size -- he's a little small for his age -- and for being the middle child. He also thinks that an extra year will let him develop his own identity at school, so the teachers won't expect him to perform like his brother.

The boys seem to have about the same IQ but their abilities are different.

Would we be doing our middle son a grave disservice if we held him back? He would then be a lot older than most of his classmates -- which isn't unheard of -- but would he be too old for them, or too smart for them?

A. It sounds like you and your husband have gotten yourselves into the same state of high anxiety that afflicts most pre-K parents.

It sends them to every nursery school meeting and precipitates countless debates -- on juice vs. punch, or on the nutritional value of health food cookies vs. the psychological comfort of Oreos. And yet three years later these same parents will skip most of their PTA meetings, even if the classrooms are crowded and the school budget has just been cut.

They don't love these older children less, they're just able -- at last -- to let them go. This isn't to denigrate your concerns, but to put them in perspective. It's natural to protect your fledglings when they start to leave the nest but sometimes you can protect them too much.

You and your husband may feel better if you make long-range school plans, but your child is still going to have some bad days, some bad marks and some bad teachers whether you hold him back or not. And while this wider spacing won't hurt your son, it won't strengthen his identity either (and the right nursery school won't get him into Harvard).

The kindergarten decision shouldn't be based on a child's rank in the family, or even his size, but on his maturity. Although boys usually develop about six months later than girls, they're generally ready for kindergarten by their fifth birthdays, as long as their neurological and emotional growth has kept up with their chronological age.

Because children develop in spurts, you can't really decide until next year. If your son is on track with the children in nursery school, however, he should do fine in pre-K this year, and kindergarten the year after.

You'll know he's ready for kindergarten if he can run, hop, jump, clap, throw a ball, button, zip, cut, paste, use crayons and pencils, and build with blocks, as well as listen -- and understand -- a story, follow simple directions, recognize and match shapes, colors, numbers, letters and count to 10 -- guidelines you'll find in "The National PTA Talks to Parents," by Melitta J. Cutright (Doubleday; $8.95).

A kindergartner also must be able to work alone and with others, to play games with them and to share. If he is much more babyish than they are, he won't have as many friends and he will think of himself as a loser -- the one thing you want to help him avoid. Rightly or wrongly, a schoolchild values the opinion of his classmates even more than his teacher, and judges himself by how well he thinks they like him.

If you don't think he's quite ready for kindergarten at 5 -- and therefore ready for first grade at 6 -- he can repeat pre-K or go to kindergarten and then to junior primary, if there's one at his school. It's a good interim class for many children.

This delay probably won't be necessary, however, and that would be a blessing, for your sons have a special edge on life. Their closeness, more than their smarts, has taught them how to create their own adventures and enjoy each other so much.

This friendship is one of the most important things you can foster now, for it will encourage them to have many of the same interests and friends -- which always makes life smoother at home -- and teach them how to build strong relationships.

Nature has set their course; you'd be wise to let them follow it. Questions may be sent to P.O. Box 15310, Washington, D.C. 20003.

Worth Noting

The Lewinsville Adult Day Healthcare Center will have an open house today, 2 to 4 p.m., at 1609 Great Falls St., McLean. Information, (703) 734-1718.