Persuasion is the process of changing or reinforcing attitudes, beliefs, or behavior.
We respond to persuasive messages in two ways: thoughtfully and mindlessly. When we are thoughtful, we listen hard to what the persuader is saying; we weigh the pros and cons of each argument. We critique the message for logic and consistency, and if we don't like what we hear, we ask questions and call for more information. When we are in the thoughtful mode, the persuasiveness of the message is determined by the merits of the case.
When we respond to messages mindlessly, our brains are locked on automatic. We don't have the time, motivation, or ability to listen intently. So instead of relying on facts, logic, and evidence to make a judgment, we take a mental shortcut and rely on our instincts to provide us with cues as to how to respond.
“The object of oratory is not truth but persuasion.”
— Thomas Babington Macaulay
Take a television debate between two politicians as an example. If you were in the thoughtful mode, you would listen hard to both sides and make your mind up based on the discussion of issues and the quality of evidence.