1. Psychological repression of parents' emotional disharmony or family setbacks leads to children's withdrawn personality and unwillingness to accept others.

2. Attachment to adults Some families keep their children in private homes for foster care, because children have never left the arms of adults since childhood and their ability to adapt to the environment is relatively poor. After attending kindergarten, I love to cry, and some even have neurological disorders: I cry to pee, but I just won't pee in the bedpan, and I will pee my pants when I take it off. I usually don't play with children, but prefer to be alone, so it is difficult to adapt to the life in the nursery.

3. Environmental constraints Some parents spoil their children too much and are too strict to cross the road. Because children have lost the opportunity to communicate with others for a long time, they are timid, and it is unnatural to meet strangers. They will not take the initiative to find children to play. Some only children don't get along well with their children because of their parents' doting, willful, overbearing and selfish personality. In a word, whether it is mental or other reasons, the common ground is the lack of communication opportunities. Therefore, parents should stimulate their children's lively nature and let them have some time to play with their partners. We should create opportunities for timid children and encourage them to get in touch with others. It is difficult for an unsociable child to adapt to the future collective life and social life.