The Secret Of Our Success by Joseph Heinrich was probably the most fascinating book I read in 2019.

Heinrich tries to explain why our species has been so successful on this planet when compared to others, most notably to our primate cousins (e.g. Chimpanzees). Most people would attribute our success to our superior intelligence, but Heinrich believes intelligence is overrated, and culture is the driving force of human success.

I'm completely convinced that Heinrich is right. Each generation of our species builds on the work of previous generations, inheriting all their ancestors' successes, improving on them slightly, then passing them onto the next generation. Or as Newton put it, each generation sees further because it is standing on the shoulders of giants. This capability of social learning is our superpower, and one that is pretty much unique to our species.

There's a fantastic review of the book here that describes Heinrich's argument in more detail. I'd recommend reading the review at the very least, if not the entire book, if the subject captivates you.