I stand by my statement, not all human beings qualify as intelligent.
Sorry, couldn't resist. 
(In case you didn't get it, gorillas have thumbs) 
He wrote if they had thumbs like us humans, as in opposable thumbs, not if they have thumbs at all.
An opposable thumb gives humans much better motor skills for gripping things and operating tools and such.
I believe apes have somewhat of an opposable thumb, but not to the extent of humans. Their thumbs are more like a 5th finger or toe, as most all primates use their hands as well as feet to move at top speed.
So maybe you helped prove your own theory of not every human having higher intelligence AXA
