This book makes easier reading than “The Stuff of Thought”, but it’s also less informative. There are many speculations, but not enough evidence.
Pinker doesn’t demonstrate exactly “how the mind creates language”, which is what the subtitle suggests and what I’m mainly interested in, but instead he expounds the theory of “Universal Grammar”, which was initially developed by Noam Chomsky.
In a nutshell, the argument is that there are so many striking similarities among the languages in the world, humans must have the universal ability as a species to create language. The fact that children can master grammar in such a short time also seems to suggest that grammar is an innate trait, a part of our physical/biological makeup.
It may be true that grammar is a “combinatorial system” that consists of invariant “deep structure” shared by all languages and features (aka. parameters) that differentiate them, but it is unclear what the invariants and parameters are. Until we can identify those, Universal Grammar is of little practical significance. However, I do find it fascinating that the structure of a sentence is very much like the tree structure in computer science, and the way people read is similar to the depth-first traversal. It may be possible to develop computer programs that can detect the invariant structural patterns, if any, underneath all the languages. That would be the proof for Universal Grammar.
Another point of interest for me is how, with the advance of neuroscience and technology, we’ve been able to isolate and identify brain regions that may be part of the language acquisition mechanism. The question is whether it is so distinct from other general purpose learning capacities that it requires a dedicated set of genes and brain regions.