The Language Instinct by Steven Pinker

This is a truly wonderful book, and probably the best popular science book of recent years.  Pinker writes with authority, clarity, and generosity, and he writes about something that just about everybody can claim some expertise in: language.  Indeed, language is something that we are all so deeply immersed in from a very early age, that few of us realise just what a strange and unusual thing it is.

Pinker carefully guides the reader through the scientific theories of language structure and development, giving just enough details, but not too much.  Some parts are quite hard-going and on my first reading, several years ago, I found myself skimming some of the later chapters.  However, this time I took the whole book more slowly and enjoyed it much more.

The underlying theme of the book is that language evolved by natural selection and that babies are born with an inbuilt instinct to try to make sense of the speech of those around them.  Pinker describes some of the beautiful simple experiments that have been performed to show this.  He also reveals the grammatical sophistication of those whose language has been looked down on as degenerate and slovenly, such as teenagers and people with regional accents, and shows how they follow rules just as precisely as any university professor or pettifogging language maven.

A few quotations from this book:

... the English past-tense ending -ed may have evolved from the verb do: He hammered was originally something like He hammer-did.

Speech is a river of breath, bent into hisses and hums by the soft flesh of the mouth and throat.

Paleontologists like to say that to a first approximation, all species are extinct ...

Complex organs evolve by small steps for the same reason that a watchmaker does not use a sledgehammer and a surgeon does not use a meat cleaver.

A few thoughts provoked by this book:

• The ability to learn languages is one of those abilities that evolution deliberately switches off beyond a certain age. This would appear to be analogous to the menopause in women. Is learning a language really so costly that switching it off like this is evolutionarily advantageous?
• Darwin showed that complex design does not necessarily imply the existence of a designer. Maybe we should now turn this argument around: wherever we think have evidence for the existence of a designer then we can be sure that natural selection has been at work.  After all, designers themselves are products of natural selection.
• A thought experiment: So you think you have free will? You think that you chose the make and the colour of your car by free will?  You think you chose the colours of your clothes by free will?  Maybe you did, but consider this: Suppose tomorrow you find out that you have an identical twin who was separated from you at birth.  And suppose further that your twin drives exactly the same make and colour of car, and wears the same coloured clothes (this sort of thing apparently does happen to identical twins separated at birth).  What then do you feel about the freedom of your will?