regressive /rɪˈɡrɛsɪv/

• 1. 

  ADJ Regressive behaviour, activities, or processes involve a return to an earlier and less advanced stage of development. (行为、活动或过程)退化的; 倒退的 [正式]

  例：

  ...some of the symptoms of regressive behaviours: thumb sucking, bed wetting, having problems sleeping.

  ...倒退行为的一些症状：吮姆指、尿床和睡眠不好。