Which behavior is characterized by increased muscle activity and is often a symptom of ADHD?

Hyperactivity is characterized by increased muscle activity and is a prominent symptom of Attention Deficit Hyperactivity Disorder (ADHD). Individuals displaying hyperactive behavior often demonstrate excessive movement, fidgeting, and an inability to stay still, which can manifest in various settings such as the classroom or at home. This symptom reflects a heightened level of energy and an overwhelming urge to engage in physical activities, which is distinct from the other symptoms typically associated with ADHD.

Impulsivity, in contrast, involves acting hastily without consideration for consequences, which does not directly relate to muscle activity levels. Inattention refers to difficulties in maintaining focus or following through on tasks, manifesting as distractibility rather than overactivity. Disorganization indicates challenges in maintaining order in thoughts or tasks, but it does not necessarily involve physical hyperactivity. Therefore, hyperactivity is the most accurate description of increased muscle activity associated with ADHD.