The principle of adding one in psychology is to attach importance to the severity of the target tactically or strategically, and on the basis of estimating the present situation, raise the difficulty or degree of coping by one level, so as to achieve the original intention of attaching importance to and preventing accidents.

This is often used in criminal psychology to achieve an overwhelming advantage.

In educational psychology, it is mainly aimed at students' possible accidents or behaviors, and the probability or degree of accidents or behaviors is raised to a higher level to achieve the purpose of solving accidents.