Stimming (self-stimulatory behavior) is a repetitive movement, sound, or action that supports nervous system regulation. For many autistic babies and children, stimming begins very early—sometimes within days or weeks of life—because it is an innate way the nervous system organizes sensory input, modulates arousal, and maintains stability. Stimming serves multiple regulatory functions. It helps balance sensory input (either increasing stimulation or dampening overload), supports emotional regula