Much has been written about the point in evolutionary history when humans split from other primates, but Nearly Human: A Gorilla’s Guide to Good Living by Andrew Grant [LibraryThing / WorldCat] makes the comparison a bit more personal than DNA analysis and diagrams of an extended family tree.
Grant compares gorilla behavior with ours and shows where it overlaps or diverges. Do they prefer the food we do? Do they interact with each other in the same ways? Do they engage in the same social order (and the same games people play)? What gestures do we have in common with them? Gestures are probably what humans notice first when making eye to eye contact with gorillas. We share many expressions and movements. The common body language isn’t too difficult to read.
The book isn’t difficult to read either. It’s quite short, written in a brisk, albeit sometimes choppy manner. I was looking for more subject depth than this book delivers, frankly, but it’s not bad as a concise introduction to gorillas and their behavior for a casual reader. And you can read it casually: the quick chapters make it an easy book to read in spurts when you find a few minutes.
I especially enjoyed how the author turned the comparison of humans and the great apes on its head in the opening pages. Grant remarked on the mutual interest of inter-species interaction that takes place whenever people see gorillas in zoos. Instead of asking (as people usually do) how human-like are they, he asks “how gorilla are we?”