[guard-of-terra]

What is "cognitive ladder"? Where does it come from? How many steps does it have? Are we the last one?

[colinm]

Probably an evolved gradation.

http://en.wikipedia.org/wiki/Mirror_test#Reactions_of_other_...

[guard-of-terra]

I can imagine a race of aliens rejecting human consciousness on the basis of them not passing Smell Mirror Test.

Let's suppose dogs will qualify which will humiliatingly put humans pretty low on the ladder.