Why do so many self-help books sound the same?

Search on Amazon under 'self-help' and you get 216,280 titles. How can there be so many books on one topic? Are authors lazy plagiarists, or is there something else going on here?

I have often wondered about this question as I go to conferences around the world, seeing the same ideas in slightly different guises. It used to drive me a little crazy, until I uncovered several insights about the nature of the brain.

It's not that authors are plagiarists, it's that there are a small set of quirks about the brain that require a lot of attention, if you want to succeed in the modern world. The reason these quirks require attention is that they are not insights we might learn automatically, like how to breathe: they require learning, like a language. And these quirks are often hard to remember because in many cases they go against what seems logical.

So what are some of these quirks? Here are five of the bigger ones.

• The brain is built to firstly minimize danger, before maximizing rewards. This means people tend to naturally err on the side of cautious, even when the opposite would be better. This is an overarching organizing principle of the brain.

• Too much uncertainty feels dangerous. It feels like possible pain so we avoid it.

• Our conscious processing capacity is small, which makes us terrible at a lot of things, including predicting what might make us happy.

• Our capacity to regulate emotions is limited, depletes fast and needs to be used quickly to be effective.

• Our intentions and goals alter the information that the brain pays attention to.

One reason there's so many books on these themes is that we need constant reminders, in different forms, of these ideas. The brain is highly dynamic, constantly changing, affected by your thoughts and environment, the people around you.

Your brain is more like a forest than a computer, with connections changing constantly, with the light, with the time of day, with the seasons. Because there is so much change going on up there, the ‘use it or lose it' principle is alive and well. Someone who has only ever spoken English their whole life who goes to live in France for 6 months may be surprised to discover their English had gone backwards a little on returning. Qualities, skills or habits we want to maintain, like keeping our goals in mind, require focus, even deeply embedded ones. Focusing your attention actually creates or embeds circuits.

Another reason there are so many books on a limited set of themes is because there are so many different people. All our brains, on one level, are very different. One study by neuroscientist Dr. Robert Coghill found that people don't process something as basic as a simple pain stimulus the same way in the brain, once the information hits the cortex. Different brains require different contexts and messages.

What about the fact that the same ideas keep reappearing through history? I propose that this is because these ideas can be more easily digested if explained using the language and metaphors of that era. Images and stories activate vast brain networks more than plain information, but we're more likely to connect to images and stories that are familiar.

Next time you read a book or go to a conference and hear an idea you've heard before, ask yourself what quirk of the brain is being addressed. Understanding why all these books say the same thing can help you pay more attention to the common threads, thus further embedding the core ideas. It can also reduce the slight discomfort generated by uncertainty of seeing so many of the same ideas. And even make you nicer to authors.