Demons, Deliverance, and Discernment by Father Mike Driscoll

"Because of demons' greater intelligence, memory, and powers of observation, they are much better at interpreting human behavior and thought than we are. The demons can listen to us and observe us carefully and may be able to see or hear subtle physical signs that show our emotions. Therefore, even though God alone knows all of our thoughts, demons can readily analyze what we are thinking and feeling and make accurate predictions."

(pg. 42)