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5 Monkeys; The Primitive Cascade

If you watch 5 Monkeys Video, you’ll see a psychological experiment performed on a group of monkeys.  Five monkeys are put into a cage, and a banana is placed at the top of a staircase.  When a monkey goes to take the banana, the other four monkeys in the cage are sprayed with cold water.  After a couple attempts at the banana, no monkeys climb the ladder.  The water is removed and, a monkey is swapped out with a new monkey.  This new monkey makes an attempt at the banana, and is attacked by the other four monkeys.  He no longer tries to take the banana.  Another old monkey is swapped out for a new.  Again, this new monkey makes an attempt at the banana, and is attacked by the older monkeys (including the previously new monkey).  This happens until all the monkeys in the cage are “new” monkeys.  None of the current monkeys climb the ladder, and they attack any new monkey that attempts to climb the ladder, but they have no idea why.  They are just following the precedent set by the monkeys before them.  This parallels the idea of information cascades.

Information cascades are based on personal information and information gained by the group as a whole.  If we remove “personal information” and solely rely on the information gained by the group, situations like the monkey experiment discussed above will arise.  People follow blindly the order that is set before them. The article also tells a couple anecdotes, all reiterating the same point.  Behavior in groups tends to follow a sort of information cascade.  Once a precedent has bent set, it’s very hard to break.  This is even true of the urn experiment we talked about in great detail during class.  The trend of red guesses cannot be stopped until new information is acquired.  In the situation with the five monkeys and behavior in social groups, however, even when new information arises, the precedent set is still too strong to overcome.  The new information is ridiculed, and the group is stuck on the same path it’s always been on.

Discussion arises (in the comments at the end of the article and at the end of the 5 monkeys video) on whether or not this type of information cascade has any benefits.  The end of the video clip goes into a bit about how this kind of behavior deters any positive changes to be made in governments.  (I think that’s why the monkeys were all wearing suits.)  In the article, however, one of the comments mentions that learning from past mistakes is how wisdom is acquired, “Isn’t [it] important in many cases to learn from the wisdom of those that came before us – Isn’t that how we know which plants are edible, which poisonous?”  Both sides have valid points.  These information cascades are like the ones discussed in class in that they are built on very little information but, unlike the ones in class, they are not fragile.


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