In order to stay alive, birds have to solve a conundrum: they need to be able to feed and watch out for predators simultaneously. How are you to focus closely on what you are doing when you are trying to pick out that grain of seed from the grit on which it lies while, at the same time, keeping the broadest possible open attention to whatever may be, in order to avoid being eaten? It’s a bit like trying to pat your head while rubbing your stomach at the same time – only worse, because it is impossible. What we know is that the difference in attention between the hemispheres makes the apparently impossible possible. Birds pay narrowly focused attention with their right eye (left hemisphere)

to what they are eating, while keeping their left eye (right hemisphere) open for predators. At the same time, birds and animals use their left eye (right hemisphere) in forming bonds with others of their kind. And this difference is preserved as we evolve. In fact, it seems that the left hemisphere specialises in a sort of piecemeal attention that helps us to make use of the world, but in doing so it alters our relationship with it. Equally, the right hemisphere subserves a broad, open attention that enables us to see ourselves connected to – and, in the human case, to empathise with – whatever is other than ourselves.