我儿子晟晟4岁半,比较乖,性格内向,不大主动叫人。他有一个令我头痛的坏习惯——咬手指甲。1岁半就开始咬,挨我的训斥后会稍好一些,但也只是从咬十个手指甲改为两个手指甲。3岁进幼儿园后就咬得更厉害了,他不大爱玩,一空下来就咬指甲。去年基本就没剪过指甲。昨晚跟他约定:如果能改掉这个坏习惯,国庆节就带他去外地玩,否则就把他关在门外。他答应得很好:“妈妈,我一定不咬了!”(这样的保证也不知说了多少遍了!)可今天一看,又咬过了,我下了狠心把他关在门外。他在门外大哭求饶,后来惊动了邻居,他们来劝我,我才放他进门。听说有的孩子上初中甚至大学了都难改咬手指甲的习惯,我几乎要绝望了。我想请教专家,这是不是一种心理障碍?有办法矫正吗? 浙江杭州韩淑萍 Sheng Sheng my son 4 years and a half, more good, introverted, not very active. He has a bad habit that makes me headache - bite my nails. One and a half years old began to bite, after my reprimand will be slightly better, but only from bite ten fingernails to two fingernails. 3 years old after entering the kindergarten to bite even worse, he is not love to play, nip nails. Last year, basically did not cut nails. Last night, he agreed: If you can get rid of this bad habit, National Day took him to the field to play, or put him shut at the door. He promised very well: “Mom, I must not bite!” (I do not know how many times this guarantee!) But today I saw and bite off, I am cruel to him off the door. He cried out at the door begging for mercy, and later alerted the neighbors, they advised me, I let him go. I heard that some children in junior high school and even difficult to change the habit of biting fingernails, I almost despair. I would like to ask experts, this is not a psychological disorder? There are ways to correct it? Hangzhou, Zhejiang Han Shuping