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Updated: Monday, April 12, 1999 10:50:18 AM

Schemas & Just world Belief Classical Conditioning Operant Conditioning
Sensory Memory Short Term Memory Long Term Memory
Confidence and Memory Heuristics Attribution
Norms Social Influence & Obedience All Notes in one view

Section 2: Heuristics

Heuristics are simple rules
        Although their automatic use often results in easy answers, they are sometimes incorrect
Representative heuristic

Judgments are biased by our assessment of the degree to which the salient (a feature that stands out) features of specific instances resemble general categories.

The representative heuristic may explain why only certain operant-reinforced associations are easily learned.

Example of the Representative heuristics…

What is the most likely sequence for the next 6 babies born in the U.S. (b=boy, g=girl)




  Correct mathematical probability theory says #1 because there are slightly more boys than girls born in the US.  However, 1 2 and 3 are about equal in probability.  The reason why people would lean towards #3 is because it looks like it is random distribution. Most people know that the gender of a child is random.

A professor likes to write poetry is rather shy, and is small in stature. Which of the following is his field?

1) Chinese studies

2) Psychology

Correct answer would be Psychologists, based on the fact that the total number of psychologist is greater than the total number of people in the field of Chinese studies.   Therefore, one could expect many psychologists to express these characteristics, even though these characteristics don't typify that of psychologists in general.  We often ignore the total number of occurrences (base rate) in a population when making these kinds of decisions.

Availability Heuristic -

Judgment are biased by how easily specific examples are recalled.
Easier = more frequent or more causally related
What is in our short term memories affects our decisions

Example of the Representative heuristics:

Which of the following do more people die of:
Motor Vehicle Accidents

Correct answer: Stroke.   Although motor vehicle accidents are more widely publicized and we encounter them more in every day life (for example on the side of the road on our way to work or school), these accident's are rarely fatal. Strokes are less publicized (found in the obituary section) and account for more deaths in the US.

Which of the following do more people die of:

Correct answer: Diabetes.   For the same reasons as the previous example: people are more drawn to choosing homicide.  Homicide is more frequently portrayed in TV dramas.

Are there more words that begin with the letter "r"
that have "r" as the third letter?

Correct answer is R as the third letter. Because it is easier for us to list off words which start with "R" than have "R" as the third letter, we are more susceptible to choose what is readily available to us.

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    This chart shows how being a member of a specific group could predispose you to believe that more people of the general population will also be part of your group.  When asked how many people are vegetarians, the vegetarians estimated a greater number than non vegetarians.  This effect can be explained through the availability heuristic.   Vegetarians think that there are more vegetarians because more of the people that they know are vegetarian.

By altering actors and observers perspectives through videotape replays, mirrors, or other methods, one can correspondingly alter actors’ and observer’s causal assessments."
        Human inference
        Nisbett & Ross 1980

    By changing the perspective, we also can change the availability of information that jurors use to reach a verdict.  In the Rodney King trial, for example, all the officers who beat Rodney King were acquitted.  The lawyers defending the police, replayed the videotape of the beating, stopping it frequently to make information available to the jurors.  This information consisted of what the police were thinking as well as Rodney King's supposed intentions.  Using this technique of manipulating availability, they were able to convince the jury that Rodney King was the cause of his own beating.





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