System 1 is an autopilot system in which we do things easier and through repetition. It filters out things in the environment that are irrelevant to you at that moment; it has high efficiency. It is based on the idea that neurons that fire together, wire together. It primes an idea so that one idea is more easily activated (wakening of associations). System 2 corrects and adjusts the perceptual blindness associated with system 1. It allows flexibility, giving nuance and precision more importance. Basically, system 1 is more associative and intuitive while system 2 is analytical and deliberative. We (our selves) are not unitary constructs. Rather, there are two cognitive processes that are in competition with each other. What do cows drink? System 1 would say "milk", but system 2 would say "water." Joan's father has five daughters: Lala, Lele, Lili, Lolo, and...Joan, not Lulu. In one study, people who unscrambled sentences with words related to senior citizens walked more slowly. The operations of System 1 are fast, effortless, associative, and difficult to control or modify. The operations of System 2 are slower, serial, effortful, and deliberately controlled; they are also relatively flexible and potentially rule-governed. Processes comprising operations of System 1 (including heuristics) are similar to the features of sensory perception. They make and have a bias towards making thinking cheap. The automatic system deals with information overload.