The brain left/right tendency is one of those psychophysical areas that have entered the popular domain. Like most things that enter the popular domain, controversy and myth touting soon manifest.

So what's the issue?

Well, as is always the case when something becomes popular, it necessarily gets simplified. Scientists don't like this simplification and see it as misinformation. The authors of popular books say it makes the information accessible and useable.

So should we listen to popular scientific theory?

Well, let's start by giving a quick synopsis of the simple theory...

The simple theory

Before specialist experiments were carried out, people were already aware that some people were left-handed and others right-handed. They also knew that language seemed to be located on the left side of the brain, from observations of patients with brain injuries.

When Roger Sperry (right) performed his experiments in the 1960s, he shed some light on what was going on.

His experiments were performed on epileptic patients who had been through a surgical procedure to stop their seizures. The procedure was a last resort measure which involved severing the connection between each side of the brain. This provided a unique way of studying each side separately.

Sperry and subsequent experimenters found that the left hemisphere of the brain was involved in sequential processes (which included language) and the right side with more global/simultaneous processes.

Whereas the right side of the brain had previously been deemed less important, it had now been shown that this side of the brain just did a different job to left side.

This then manifested into a concern with the way things were taught in schools. There was a worry that school was very much left dominant, with subjects such as maths and English bullying out the more creative art-based subjects.

Then in Betty Edward's Drawing on the Right Side of the Brain it was claimed that when people struggled to draw it was because the left-half of the brain was trying to take over an activity that was predominantly right brained.

The Real Science

So what's wrong with this idea?

Well the scientific community say it is far too simplistic and doesn't quite stand up to scrutiny. Whereas language is primarily located in the left of the brain, most activities actually make good use of both sides of the brain.

Take speech as an example. Brain imaging studies have shown that the grammar and production of words is a function of the left side of the brain, but the right side is also involved - dealing with such things as intonation.

So rather than particular activities being processed in different side of the brain, it is the different types of task within an activity which are divided.

In my view this really just makes everything clearer. I never really believed that half my brain shut down while I was doing maths, and then suddenly lit up when I entered my art class.

Are you left or right brain dominant and does it matter?

The left-brain/right-brain debate has become a way of describing if one is artistic and creative or mathematical and logical. Many would argue, the reality of what parts of the brain are being used almost don't matter as it is used as more of a metaphor than anything else. In her updated The New Drawing on the Right Side of the Brain, Betty Edwards points out:

Clearly, for educators like myself, the precise location of these modes in the individual brain is not an important issue. What is important is that incoming information can be handled in two fundamentally different ways and the two modes can apparently work together in a vast array of combinations. Since the late 1970s, I have used the term L-mode and R-mode to try to avoid the location controversy. The terms are intended to differentiate the major modes of cognition, regardless of where they are located in the individual brain.
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I agree with this statement to a certain extent, but the brain science does bring up an interesting point...

While specific activities tend to be carried out across both sides of the brain, each side appears to have a particular style of activity that it favours. The right side seems to be more interested in seeing things as a whole, whereas the left side is more interested in sequence.

It is also clear that that each side's favoured style is more useful for different subjects. Or to be more precise, different parts of a particular subject are more appropriate to a particular style. Betty Edward's utilised this understanding to teach drawing.

But if you use both sides of the brain for most tasks, can one side really have become dominant in society at the expense of the other side? For example, if you subconsciously use your imagination while working out math problems, can we really say that the left brain is more dominant than the right? Or, indeed, is one style of thinking more dominant than the other?

While many people are more creative and spontaneous and others more logical and methodical, I tend to shy away from naming anyone either left or right brain dominant. Labelling of individuals usually leads to the individual living up to that label - a kind of self-fulfilling prophecy.

Having said that, I think a left or right brain tendency is quite possible. Even though a particular subject may require both styles of thinking, this does not necessarily mean that a particular individual will be utilising both effectively.

How to balance the brain's left/right tendency

People have the potential to think in either way; they simply need to be trained in these different ways. When they are, the most useful ways of thinking will activate at the appropriate time.

As I always advocate, to create a well rounded and adaptable intellect it is always a good idea to challenge yourself to do things that you cannot do. There is a tendency for people to do the things that they find easiest, but focusing on the areas of life they find hardest will produce the most benefit.

An inability to think in a free, imaginative right-brain way will stifle left-brain activities such as mathematics. Often a plateau can be pushed past, by taking a break from that activity and training in something else.

Many of the techniques on this site will also encourage you to think in specific ways you may not feel comfortable with; and this will help create an appropriate balance.