Activity level refers to the relative amounts of motor behavior produced by children and includes everything from a toddler's first steps to a middle-school child's skillful soccer playing. Activity level is measured in a number of ways, ranging from parental observations to computer analysis. Regardless of how it is measured, activity level is usually related to other factors, such as gender, age, and individual differences. Boys are usually more active than girls, and rates of movement are generally the highest between the ages of seven and nine. A child's relative periods of activity and inactivity have been viewed as a stable feature of temperament, suggesting that active infants may become active children, and active children may become extroverted adults. If very high levels of activity accompany poor concentration, disorganization, an inability to "sit still," high levels of distractability, impulsiveness, and little sustained attention, then a diagnosis of hyperactivity with Attention Deficit Hyperactivity Disorder (ADHD) may be indicated.
Buss, Arnold H., and Robert B. Plomin. Temperament: Early Developing Personality Traits. Hillsdale, NJ: Lawrence Erlbaum, 1984.
See: ATTENTION DEFICIT HYPERACTIVITY DISORDER