A new teacher was trying out something

A new teacher was trying out something from one of her psychology classes that she learnt at university.

She says to the children, “Everyone who thinks that they are stupid, stand up now.”

After a little while Johnny stands up.

The teacher asks him, “why did you stand up Johnny? Do you really think you are stupid?”

Johnny replies, “No Miss, but I hated seeing you standing there all by yourself.”