The manifestations of mental retardation in 6-year-olds include hyperactivity, weak verbal expression and poor hands-on ability. 1. Hyperactivity: many 6-year-old children with mental retardation cannot stay quiet for a while and are active all the time. This kind of hyperactivity is different from the normal children’s lively and naughty, it is a kind of unstoppable excitement. 2. Weak language expression ability: 6-year-old children with mental retardation may also have weak language expression ability, which is clinically manifested as slurred pronunciation, late opening of the mouth to speak, and slow learning of language. 3. Poor manual ability: it will be manifested by developmental delay, motor clumsiness, backwardness, etc., poor fine movements, such as picking up bottle caps, rubbing screw caps, and poor functional dexterity of the hands. If the 6-year-old child appeared in the above situation, parents should take the child to the regular hospital in a timely manner, under the guidance of professional doctors to take targeted treatment.