I wrote a post looking at the two numbers "1 x 2 x 3 x 4 x 5 x 6 x 7 x 8" made a median estimate of 512, "8 x 7 x 6 x 5 x 4 x 3 x 2 x 1" made a median estimate of 2,250.
From a computer science perspective.
One of the interesting things I noticed was that both averaged guesses are close to powers of two and that given a little bit of fudging you can make a pretty good guess about how our brain creates that guess.
IE
2^8 + 2^1 = 512 and 2^8+ 2^3 = 2048
(note that 2^3 is 8, but 2^1 is 2 instead of 1, so if you fudge all the numbers to their closest power of two and then do multiplication you get the answer they created.
So for
4 x 3 x 2 x 1 you would get 2^4 + 2^2 which is 64 and 1 x 2 x 3 x 4 you would get 2^2 + 2^1 which is 32
forgot the link (althouh you can click on the name that might not be obvious)
http://www.functionalforums.com/TreeForum/index/Functional-Forums/Implementing-bias-in-AI