System 2

System 2 allocates attention to the effortful mental activities that demand it, including complex computations. The operations of System 2 are often associated with the subjective experience of agency, choice, and concentration.

System 2 have one feature in common: they require attention and are disrupted when attention is drawn away. Here are some examples:

• Brace for the starter gun in a race.
• Focus attention on the clowns in the circus.
• Focus on the voice of a particular person in a crowded and noisy room.
• Look for a woman with white hair. Search memory to identify a surprising sound.
• Maintain a faster walking speed than is natural for you.
• Monitor the appropriateness of your behavior in a social situation.
• Count the occurrences of the letter a in a page of text.
• Tell someone your phone number.
• Park in a narrow space (for most people except garage attendants).
• Compare two washing machines for overall value.
• Fill out a tax form.
• Check the validity of a complex logical argument