As you read this post, your computer is probably busy. You may have multiple programs running in the background, with email clients, anti-virus software or file-sharing software all competing for valuable memory. The ability of computers to multi-task has grown substantially in recent years, as processors have become increasingly powerful.

Evolution has chartered a similar course, and humans are particularly talented at dividing our attention among multiple priorities. Now scientists are showing that the asymmetrical differences between the two sides of our brain are essential for this ability to multi-task.

In the animal world, the ability to multi-task is a matter of life and death. Many species must be ever-watchful for food, while simultaneously looking out for predators who would view them