posted 24 February 2005


William H. Calvin, "The Problem with Guessing Correctly." Human Behavior and Evolution Society (HBES, June 1-5, 2005) at the University of Texas, Austin. See also

William H. Calvin 
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 University of Washington



The Problem with Guessing Correctly

Guessing another’s intentions may be easy if the situation is familiar and the individual is well known.  It is novelty that makes “mind reading” difficult, especially when there is a premium on being right the first time.  I am going to assume some abilities in the great apes and then ask what other evolutionary developments might have augmented them.  Increased sharing involved some keeping track of “who owes what to whom” and cheater detection.  Increased mimicry, so handy for imagining another’s movement planning, was likely gradually augmented.  Ballistic movements improved over the apes and they require “get set” planning that is usually right the first time (or dinner runs away). 

            Yet despite all this, there are long periods of stasis in toolmaking.  Even after we became Homo sapiens 200,000 years ago, progress was very slow until the creative explosion about 50,000 years ago.  This suggests that we should look at this recent expansion in higher intellectual functions for clues to what makes us so good at guessing right the first time.



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