The terms System 1 and System 2 (see “System 2”) were popularized by the work of Daniel Kahneman in his book, Thinking Fast and Slow (2011). System 1 refers to rapid, nonconscious, involuntary processing of a stimulus or experience that produces an automatic response. An example is an adult putting on a shoe in the morning. This requires little conscious effort and can be done in parallel to a task requiring conscious-level awareness, such as a conversation. On the contrary, at a young age, learning to tie one’s shoelaces would engage the more conscious, deliberate System 2. The System 1/ System 2 paradigm is a conceptual framework and does not represent specific regions of the brain, specialized for System 1 or System 2 processing.
