What is a Heuristic?

Let me leave my story for a brief explanation of heuristics and biases.

The brilliant psychologist, Dr. Daniel Kahneman, in his book Thinking, Fast and Slow described the brain as having 2 systems, System 1 and 2. System 1 is intuitive, emotional, automatic, and provides us with quick responses and judgements. System 2 is used when we stop to think and analyze things and is much slower, and as he described it, lazier. System 1 saves us a lot of time and is filled with shortcuts.  

We generally use our System 1 brain for most of life; using System 2 takes concerted effort. Although System 1 saves us a lot of trouble, it is also gullible, favoring belief and easy acceptance. System 2 readily provides explanations for the decisions of System 1. This tendency had serious consequences in my life.

System 1 is filled with pre-programed heuristics - mental shortcuts that allow us to make decisions quickly and easily. We do these things unconsciously. Many times they are helpful, but they can also lead to us errors in thinking which are called biases.

The availability heuristic is the innate mental shortcut where we come to accept and deem important things that are oft repeated. The greater the ease of recall, the more value we give to the information. With hours devoted to Word Time and memorization each day, you can imagine what I, and all those around me, were considering most vital.

"A reliable way to make people believe in falsehoods is frequent repetition, because familiarity is not easily distinguished from truth." Thinking, Fast and Slow, Daniel Kahneman