More on numeric intuition: Log or linear? (Science, 2008)

Following up on the previous post, I thought I’d look a little more into Spelke’s research, and found this really cool paper from Science in 2008: “Log or Linear? Distinct Intuitions of the Number Scale in Western and Amazonian Indigene Cultures,”‘ by Stanislas Dehaene, Véronique Izard, Elizabeth Spelke, and Pierre Pica (ungated link).  Here’s the abstract,

The mapping of numbers onto space is fundamental to measurement and to mathematics. Is this mapping a cultural invention or a universal intuition shared by all humans regardless of culture and education? We probed number-space mappings in the Mundurucu, an Amazonian indigene group with a reduced numerical lexicon and little or no formal education. At all ages, the Mundurucu mapped symbolic and nonsymbolic numbers onto a logarithmic scale, whereas Western adults used linear mapping with small or symbolic numbers and logarithmic mapping when numbers were presented nonsymbolically under conditions that discouraged counting. This indicates that the mapping of numbers onto space is a universal intuition and that this initial intuition of number is logarithmic. The concept of a linear number line appears to be a cultural invention that fails to develop in the absence of formal education.

I wonder if anyone has spelled out the implications of this insight for, say, intuitive risk judgments?

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