What clues can be used to understand the psychological state of others?

What clues can be used to understand the psychological state of others? There are many ways:

First, as the saying goes, the eyes are the windows to the soul. Pay attention to the other person's eyes when you speak, and see if they are flickering.

Second, observe each other's movements. There are some casual gestures that will expose each other's psychological state.

Third, observe each other's expressions. If I remember correctly, there is a course in psychology about micro-expression. It's also interesting to watch, which can help you better understand the psychological state of others.

Fourth, we can also judge each other's psychological state from their conversation content and tone.

In short, there are many ways to judge other people's psychological state. The above method is just very simple. If you are interested, you can read books on psychology, and you will know more.