Divided brains

Many people assume that splitting the brain into two specialised halves is a human trait. Scientists now know that brains are lopsided in similar ways across the animal kingdom, from fish and reptiles to birds and mammals, and even in a few invertebrates. Across vertebrates, the underlying layout turns out to follow much the same blueprint.

The book looks at this lateralisation from four angles: what it does, how it evolved, how it develops, and what causes it. Its account of evolution starts with the earliest ancestors and follows the trait through fish, reptiles, birds and mammals, humans included. Readers will also find discussion of the advantages a divided brain may offer and of how experience shapes that division as an animal grows.

The final chapter sets out open questions and suggests where future research should go. The authors are specialists in the field, and they explain the latest findings in a clear, engaging way, which makes the volume useful to anyone curious about the biology and behaviour of brain asymmetry.