A complex language is one of our defining characteristics as human beings, making it possible to communicate a wide range of abstract and concrete concepts to others of our species. The sheer complexity is unique: based on a limited range of speech sounds every human language has a vocabulary of tens of thousands of words, enabling us to build an unlimited number of phrases and sentences with the help of simple grammar rules.
But why and how humans developed this ability for complex language has long been debated. Is it, as linguist Noam Chomsky argued, a 'universal grammar' - an innate ability hardwired into our genes? Was it a gradual response to threats in the environment, or a sudden leap that gave one prehistoric tribe the edge over others?
In 1994 the American psychologist Steven Pinker published The Language Instinct, a widely influential bestseller rated among the top 10 books of 1994 by the New York Times. Studying children's language development, Pinker argued that it was neither exclusively a genetic, inbuilt brain function or a result of interaction with the environment. Instead, it was a combination of the two - a 'language instinct' that could have evolved via natural selection and emerge through social interaction.
As well as bringing linguistics and psychology to a wide audience, Pinker provided a new angle on the dominant 'universal grammar' theory – potentially pushing the dawn of human language much further back than a mere 30,000 years ago. His theories are still under debate, but they have made a big impact on the study of human communication.