Watching this NOVA special, Ape Genius, I almost fell over (while exercising!) when I heard one of the researchers say that in their quest to understand the apes and their relation to us, they were trying to find out "what's the little difference that makes the big difference."
And these were not neurologists, talking about brain anatomy/physiology differences! These were cognitive psychologists and anthropologists. I'm afraid it is yet another example of the deterioration of education.
"The Difference of Man and the Difference It Makes"is Reason! Humankind's ability to conceptualize abstract ideas. It makes ALL the difference.
I suspect this ignorance on the part of the scientists is a result of the century+ attack on Reason and that attack's influence in the humanities and sciences.