Whether a baby’s intellectual development is normal or not is reflected in many aspects, but due to parents’ neglect, some babies’ intellectual development problems are only noticed by parents when they are clearly manifested, which is very dangerous. Therefore, in the process of early parenting, it is necessary to observe the baby’s various manifestations in a timely manner, as well as to determine the level of intellectual development of the baby as early as possible. Infants and young children with intellectual developmental disorders have the following specific manifestations: 1, weak coordination of the four limbs. After walking, the two feet still touch each other, until 2-3 years old still appear. 2, poor visual function development, do not pay attention to the surrounding people and things. 3.Smile appears very late, not pay attention to others’ speech, lack of response to sound. 4.Chewing is late, feeding is difficult, and when eating solid food, swallowing disorders and vomiting occur easily. 5.Don’t love to cry and pout, very quiet. 6.Normal babies often lie in bed and look at their hands when they are 3-4 months old. However, mentally retarded babies continue to have such behavior after 6 months. 7. Normal babies often put things into their mouths after 6-12 months and stop using their mouths when their hands are more skillful. However, babies with backward intellectual development continue to use their mouths until very late in life, sometimes putting toys into their mouths even at the age of 2-3 years. 8. Normal babies stop throwing things around after 15-16 months, while developmentally delayed babies last longer. 9. Normal babies stop drooling at the age of 1 year, while babies with defects last longer. 10. During waking hours, mentally retarded babies have teething movements, while normal babies do not. 11, mental retardation babies sometimes need repeated or continuous stimulation to cause crying, crying often emit guttural sounds, sometimes cry shrill or screaming, and sometimes weak cry. Normal babies often have pitch changes in their cries. 12, the lack of interest in the surrounding things or interest in a short period of time, mental inattention, slow reaction is an important characteristic of mental retardation. 13. Mental retardation is characterized by excessive sleepiness and aimless hyperactivity. In addition to observing the above behaviors, parents can take their babies to take an intelligence test, which can measure the level of intellectual development of the baby. However, you cannot define your baby’s intelligence according to this test. Parents should observe their babies’ behaviors more often and try to detect, intervene and return to their babies at an early stage.