The contrast effect
Human beings have difficulty in thinking in absolute terms. We judge things by contrast. Something looks ugly, cheap or small if it is sitting next to something beautiful, expensive or large. The positive qualities of something is felt only when it is compared to something less positive. Your house is big if all the other houses in the lane are smaller. If all the houses in your lane are big, then you are living in an average house. If all the other houses are bigger than yours, you feel that you are living in a hut!
We create a picture of the world in our minds using the examples that most readily come to mind. In other words, we decide things on the basis of available information. The problem is, just because some information is available to us, it need not be all that there is to reality. Because of availability bias, we go through life with an inadequate list of guidelines. For example, a girl who has been born into a highly intellectual environment and is not exposed to anything else believes that the world is made up of only intellectual people, and is unpleasantly surprised when she meets someone who cannot discuss Plato or Aristotle. The only way to combat the availability bias is to be exposed to ideas and people who are different from what you already know.