Book Definition: Readiness to detect a particular stimulus in a given context – as when a person who is afraid interprets an unfamiliar sound in the night as a threat.

In your own words:

  • A mental predisposition to perceive one thing and not another.


  • You tell your friend to spell the word fork, and say it 5 times. Then you ask them the question "what do you eat soup with?" They answer "Fork." They answer incorrectly because you have just put the idea of a fork in their mind and that they expect the next word they say to be fork.
  • Say the words silk dilk rilk tilk and then ask a friend what cows drink. Their perceptual set will cause them to say "milk" when cows really drink water.
  • When you're driving on the highway, you don't expect a bicyclist or a motorcyclist to cut you off because you are instead being cautious of a car cutting you off.
  • You see your friend in the hall who is expecting you to say "How's it going?", but instead you say "Whats up?" and your friend says "Good".

This is a perceptual set that causes you see either the Letter B or the number 13

external image women.gif

You can see a young woman and old lady