FT.com / UK - Six Degrees Of Separation? We Can Only Manage Five

FT.com / UK - Six Degrees Of Separation? We Can Only Manage Five

Six Degrees Of Separation? We Can Only Manage Five
By Tim Harford
Published: March 7 2009 02:00 Last updated: March 7 2009 02:00

Excerpt:

The human brain simply may not be wired up to deal with lots of different levels of value. A series of psychological experiments, many dating back to the 1950s, shows that we cannot distinguish between more than about five degrees of... well, almost anything: sweetness in a solution; saltiness; the pitch of a note; brightness; the intensity of an electric shock; the length of a line; or the pungency of a smell. The details vary, but the level of consistency is surprising.

Nick Chater, a psychologist at University College London, argues that the human brain doesn't have an internal scale for these stimuli, nor for "utility" or "value". Instead the brain makes comparisons: that light was brighter than the previous light. We can just about wrap our minds around the idea of "much brighter" by comparing a recent gap in brightness with some previous gap in brightness. If the brain works in this binary way, it is easy to see why it struggles to compare more than about five different brightnesses - or sweetnesses, lengths, or "utilities".


Read full article: http://www.ft.com/cms/s/0/4ce4022e-0ab9-11de-95ed-0000779fd2ac.html?nclick_check=1
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This posting was made my Jim Jacobs, President & CEO of Jacobs Executive Advisors. Jim also serves as Leader of Jacobs Advisors' Insurance Practice.