Matt’s Reviews > Thinking, Fast and Slow > Status Update

System 1 is automatic and quick. You use it to see that a person is angry. System 2 is slow and effortful. You use it to figure 17 x 24. Conflict can occur. You can not read words you know and see (system 1) even if trying to do a complicated system 2 task. System 1 tells you that lines in the Muller-Lyer illusion differ in length, even if system 3 has measured and knows this is false.