As some readers may remember, I did a big Observer feature recently about Steven Pinker’s new book, which I think is a really significant and important work. So it was astonishing to learn yesterday from a well-informed source that UK sales of the book have been “very disappointing”.

This is really surprising given that: it’s a compelling and authoritative book; its author is a world-famous academic with a string of earlier best-sellers to his name; and the UK publishers (Penguin) organised a model pre-publication campaign for it which included, among other things, an RSA lecture given by him.

So why hasn’t The Better Angels of our Nature taken off in the UK? Two thoughts come to mind:

1. It’s too long. Or, rather, it’s 800-page bulk makes it look too intimidating — a bit like War and Peace or Ulysses, the kind of read that people think they could only tackle on a desert island.*

2. (Possibly allied to 1) The pre-publication publicity campaign had the counter-intuitive effect of making people think that they already knew enough about the book and so didn’t need to read it. This was because the ‘elevator pitch’ for it is easy to articulate: it is that, contrary to popular prejudice and conventional wisdom, violence in human societies has been steadily decreasing over a period of thousands of years. That is indeed a dramatic and compelling idea, but it’s not the only important thing to emerge from the book. First of all, there’s the care with which Pinker has marshalled the empirical evidence for his conclusion. And then there’s his intriguing, extensive and thoughtful examination of the possible causes for the decline in violence. So by inferring that the elevator pitch is all they need to know about the book, people are missing out on some really interesting stuff.

* Full disclosure: I’ve been putting off reading Anthony Briggs’s translation of War and Peace.

LATER: Two interesting comments. Jon Crowcroft (who is halfway through the book) thinks that “its not about the financial crisis so it isn’t a hot enough topic – i think it will be a slow burner – it is good, but it is too long and repetitive”. And Helle Porsdam asks, “Could another reason be that most people are not interested in reading all his terrible details about ways in which human beings have tortured and killed each other down through history – altogether too violent?”