We have a 9-year-old boy who is quiet, careful, thoughtful and very, very shy. Does that mean he is not “all boy”? Should we be trying to change him, to make him more assertive and aggressive?

The wonderful thing about the way human beings are designed is their marvelous variability and complexity. We are all different and unique.

My previous discussions of aggressive, risk-taking boys represent an effort to characterize young males, showing what is typical and how they are different from their sisters. However, they also differ from one another on a thousand traits.

Your son is certainly not alone in his characteristic shyness. According to the New York Longitudinal Study, approximately 15 percent of babies are somewhat quiet and passive in the nursery. That feature of their temperaments tends to be persistent throughout childhood and beyond.

They may be very spontaneous or funny when they are comfortable at home. When they are with strangers, however, their tongues are thrust into their cheeks and they don’t know what to say. Some kids are like this because they have been hurt or rejected in the past. The more likely explanation is that they were born that way.

Some parents are embarrassed by the introversion of their children and try to change them. It is a fool’s errand. No amount of goading or pushing by their parents will make them outgoing, flamboyant and confident.

My advice to you is to go with the flow. Accept your child just the way he is made. Then look for those special qualities that give your boy individuality and potential. Nurture him. Cultivate him. And then give him time to develop into his own unique personality like no other human being on Earth.

Our pediatrician told us he believes our son may have attention deficit hyperactive disorder (ADHD). Can you tell us what is known about this problem?

ADD, or attention deficit disorder, appears to be an inherited neurological syndrome that affects approximately 5 percent of children in the United States. It refers to individuals who are easily distracted, have a low tolerance for boredom or frustration, and tend to be impulsive and flighty.

Some of them are also hyperactive, and hence they are said to have ADHD (attention deficit hyperactivity disorder).

These children have a pattern of behavior that sets them up for failure in school and conflict with their parents. They have difficulty finishing tasks, remembering details, focusing on a book or assignment, or even remaining seated for more than a few minutes. Some appear to be driven from within as they race wildly from one thing to another. They are often very bright and creative, yet they’re seen as lazy, disruptive and terribly disorganized.

ADD and ADHD children often suffer from low self-esteem because they have been berated as goof-offs and anarchists who refuse to follow the rules. They sometimes have few friends because they can drive everyone crazy even those their own age.

James Dobson is president of the nonprofit organization Focus on the Family, P.O. Box 444, Colorado Springs, Colo. 80903; or www.family.org. Questions and answers are excerpted from “The Complete Marriage and Family Home Reference Guide,” published by Tyndale House.