Left-brain narrow attention, right-brain wide attention. By Iain McGilchrist, from an interview by Freddie Sayers. What a great explanation, from a foremost expert.

Every creature has to solve this conundrum: how can I eat and yet stay alive? That doesn’t sound difficult, but if you think back: for most of history, a creature has to be able to target something, follow it with its eyes, and get it very accurately. To do that it has to have very narrow attention. But if that’s the only attention it is paying, it won’t last very long, because he won’t see the predator overhead, it won’t see its mate and its offspring that also need feeding.

So there needs to be two kinds of attention, and so different are these kinds of attention that they can only come about by having two centres of awareness.

The left hemisphere has a very narrow beam, targeted on a detail which it can see very precisely. It fixes it and grabs it (and the left hemisphere controls the right hand with which most of us do the grabbing and the getting).

Whereas the right hemisphere has a broad, open, sustained vigilant attention, which is on the lookout for everything else without preconception.

So on the one hand you’ve got an attention that produces a world of tiny fragments that don’t seem connected to one another — a bit here a bit there, a bit elsewhere — that are decontextualised, disembodied.

Whereas with the right hemisphere we see that nothing really is completely separated from anything else — that ultimately, all this is on some level seamlessly interconnected, that it’s flowing and changing rather than fixed and static.

Uniqueness is something the right hemisphere sees, while the left hemisphere sees just an example of something that it uses or needs. …

So we’ve got this one world, which is composed of things that are mechanical, useful, inanimate, reducible to their parts, abstracted, decontextualised, dead; and another world, which is flowing, complex, living, changing and has all the qualities that make life worth living.

Things work well as long as the left hemisphere is carrying out work it’s deputed to do by the right hemisphere. Rather like we use a computer. The computer doesn’t really understand the data we draw from the complexity of life. That’s not its job: its job is to process data very fast, and hand us back some that we then make sense of.

Is our civilization declining in part for this reason?

The Greek and the Roman civilisation began with a sudden outburst of flourishing in which the two sides worked very well together. Then over time, they moved more and more towards the left hemisphere’s point of view.

I think this is because civilisations tend to overreach themselves. They tend to amass an empire, and then everything has to be administered: there are rules and procedures, and everything is rolled out under a bureaucracy. And what this privileges is a simple, sequential, analytic way of understanding, rather than the more complex, holistic understanding that is required and is provided by the right hemisphere. …

Male and female brains are not the same, despite what the narrative says:

To put it very simply: I think it’s certainly not true that the right hemisphere is somehow female, and the left hemisphere male. If anything, it’s the opposite.

For example, what’s established beyond doubt is women’s excellence lies in skills that are often linguistic. Whereas men may be much less linguistic, but more able to manipulate things in space. That is a right hemisphere property largely, and linguistic fluency is largely a left hemisphere property.

In utero, it is testosterone that causes the right hemisphere to expand. Women’s hemispheres are more similar to one another. I think it’s pretty indisputable that male brains are more specialised, the left and right. Whereas in female brains, there’s more overlap between the left and right.