Each child born is a unique and special person. Not surprisingly, each parent is unique, too. One of the most important tasks you face in raising your boy is learning to understand his special qualities, his strengths, and, yes, his weaknesses. He has both, and so do you. As you live and grow together, you will become more aware of the traits that make your son who he is.

Most experts now believe that temperament traits are inborn; they appear not to change much over the course of a person's life span. In other words, there are some aspects of your son's nature and personality that are simply part of the package; you cannot change them and will have to learn to work with them. Some parents and children appear to fit together as easily as peas in a pod; others will struggle for years to find connection and understanding. Why are some babies “easy” while others pose a daily challenge to their confused parents?

Stella Chess, MD, and Alexander Thomas, MD, pioneered the idea that inborn traits may influence a child's behavior. Drs. Chess and Thomas, a husband and wife team, became fascinated by the differences in human personality and behavior and began a study that lasted for decades. Babies, they believe, come into the world already equipped with a set of characteristics and traits that shape their reaction to the world around them. What appears to be difficult behavior can often be explained as the way a child's temperament expresses itself in his family and surroundings.

There are nine different dimensions of temperament, according to Drs. Chess and Thomas. Each is a continuum, and with time and familiarity, you will be able to identify your son on each dimension. Put together, these nine dimensions of temperament will help you understand your son and parent him wisely and lovingly.

• Activity. Some children are quiet by nature, while others never stop moving. And not all active children are hyperactive. Knowing your son's activity level will help you plan his day and allow for his need for movement (or quiet).

• Intensity. Your son may be reserved by nature, or he may express himself in dramatic extremes. If your son is intense by nature, your job will be to help him calm down and use words to express his needs and feelings. If he is less intense, you may need to focus on drawing him out.

• Sensitivity. Your son may never notice that he is walking barefoot across hot gravel. Or he may flinch at the elastic in his clothing and insist that his socks are too tight. Sensitivity measures your boy's ability to handle visual, auditory, and physical stimulation. He may love a crowd or crave quiet time, and he may need your help occasionally in getting what he needs. If your son seems unusually sensitive (or lacks normal sensitivity), ask your pediatrician if an evaluation might be helpful.

• Regularity. Eighteen-month-old Timmy eats all his meals on schedule and has a bowel movement at the same time every morning; his cousin Peter never follows the same routine twice. Timmy is regular, and life is much simpler for his parents than for Peter's. Regularity refers to a child's bodily functions and need for sleep, food, and bathroom time.

• Persistence. This dimension measures a child's willingness to stay focused on a task despite frustration or lack of immediate success. Understanding your son's tolerance for frustration will give you insight about how best to teach and support him.

• Distractibility. Your son may be able to tune out the television, radio, and your conversation with friends to focus on his game or book. Or he may be distracted by every noise and movement in the room. Distractibility is often a factor in how well a child performs in school.

• Approach or withdrawal. Some babies accept new people, foods, and toys eagerly, while others turn their heads away or refuse to try something new. If your son is slow to approach, you can help him best by showing patience and acceptance and by teaching coping skills as he grows.

• Adaptability. You may be blessed with a baby who will go anywhere, sleep anywhere, nurse anywhere, and be happy anywhere. Or you may have an infant who desperately needs familiar surroundings and people to feel secure. Children low in adaptability will need extra help from parents as they experience change in their daily routines.

• Mood. Some children (like some adults) see the glass as half empty, while others see it as half full. Mood — the tendency toward optimism or negativity — appears to be an inborn trait. Rather than blaming or trying to fix your little one, you can work on ways to help him see the positive side of life.

Remember, temperament traits are no one's fault — including your son's. They appear to be part of the package human beings are born with, and wise parents will learn to shape, encourage, and teach rather than blame, lecture, or nag. Knowing your son's comfort level and preferences will give you clues about how to make each day as enjoyable and easy as possible. Knowing your own temperament will help you plan for the times when you don't fit and accept them as part of the process of raising your son.