Your child is unique, and so are you. We all arrive into the world with a special combination of mental, physical, and emotional traits that make up what scientists call “disposition” or “temperament.” These traits are closely interwoven, and set the stage for how we interact with the world—and how the world responds to us.

Researchers Alexander Thomas and Stella Chess identified nine characteristics or traits that they suggest are present at birth and that continue to influence development throughout life.

• Activity Level: Amount of preferred movement and body activity.

• Regularity: Regularity and rhythm of basic biological functions, such as sleep-wake cycle, bowel elimination/feeding cycles.

• Mood: Tendency to respond to the world primarily in a positive or negative way.

• Intensity of Reactions: The output of energy or level of mood expression, either positive or negative.

• Sensitivity Threshold: Sensitivity to irritating stimuli and the amount of stimulation needed to produce a response.

• Adaptability: How easily one adapts to transitions or change in routine, like switching to a new activity.

• Approach/Withdrawal: Typical response to new situations or people.

• Distractibility: How easily one can be distracted from an activity.

• Attention and Persistence: How long one can persist at a difficult task before getting distracted or giving up.

Each of us is unique and approaches the world differently. However, three common temperament types represent different blends of the nine characteristics or traits above.

• Flexible or adaptable children tend to be happy, regular in sleeping and eating habits, adaptable, calm, and not easily upset.

• Feisty children may be fussy, irregular in feeding and sleeping habits, easily upset by noise and stimulation, and intense in their reactions.

• Fearful or cautious children may be less active or tend to be fussy, and may withdraw or react negatively to new situations. However, they may become more positive with repeated exposure to a new person, object, or situation.

Research suggests that approximately 60% of all children fit into one of these three temperament types. The remaining 40% reflect a combination of more than one.

Susie lights up when she sees new faces, while Bobby withdraws until he’s comfortable. Any sound will distract Tommy from nursing, while nothing will distract Beth. Cara and Steven are shy in new situations, while Mark and Jennifer jump right in.

While your child arrives with an innate temperament style, her behavioral style and personality are influenced by temperament, early experiences, and her interactions with you. The interaction of genes and environment also influences your child’s temperament and the wiring of her developing brain.

Remember, temperament is not destiny.