System 1 is responsible for quick decisions that appear to take little to no thought. The thoughtful and logical responses come from system 2. System 1 is active and wants to get things done with minimal effort, but system 2 is lazy and would rather rely on system 1 whenever possible.
System 1 can be easily influenced by priming, familiarity, and repetition. System 2 is deliberate and thorough and comes to more sound conclusions, but it takes longer to get there and it seems that system 1 is trying to “convince” system 2 to skip steps and get to the solution or action more quickly.