Right-Brain / Left-Brain: Fact, Theory or Myth?

Posted on 24 January, 2014 by Gary Wood

What is the right-brain/left-brain theory?

The basic premise of right-brain/left-brain (pop-) psychology is that each side of the brain is said to control different types of thinking. For each of us, one side of the brain is supposed to be dominant. So if the left side of you brain is dominant, by the theory, you would be a logical, methodical, objective, analytical scientific kind of person. However if the right side of your brain is dominant you would a more creative, artistic, intuitive, expressive, subjective kind of person. Knowing what side of brain is dominant is presumably helpful in explaining why we might meet problems with certain tasks and indeed what we might do to balance out the ‘one-sidedness’. The theory of brain-dominance is something that frequently crops up in discussions in my confidence-building workshops. Sometimes these kind of theories provide comfort because on first glance seem to offer a way to explain and structure our experience. So let’s look at the evidence.

Considering the evidence for the right-brain-left-brain

Supporters of the theory might argue that this is supported by scientific evidence, and yes of course, as with many pop-psychology theories there is a grain of truth. However, when reviewing evidence, it depends on how old the research is, whether up-to-date research has challenged initial findings, whether the original research is generalizable to the general population and who is interpreting the evidence. It’s common to see newspaper journalists report evidence-based research in a headline grabbing way. There is no space for the fine detail.

The right-brain-left-brain theory is based on the work of Roger W. Sperry in the 1960s. In psychology it’s known as the the lateralization of brain function. Our brains are comprised of two hemispheres connected by a structure called the corpus callosum which facilitates inter-hemispheric communication. So it the normal, undamaged brain, there is ‘dialogue’ between the two sides. Sperry studied epilepsy patients and discovered that seizures were reduced or ceased when the corpus callosum was cut. Through a series of experiments, Sperry (and others) were able to determine which parts of the brain were involved in various functions, including language, maths, drawing and so on.

This is the basis for the pop-psychology theory. I heard one self-styled new age guru claim that ‘old psychology is dead’ and we need to usher in the new psychology. Apparently he didn’t see the irony of citing research from the 1960s. It’s also important to correct the misnomer of two brains. A neuroscientist would not use this terminology, unless to criticise the theory. We have one brain with two hemispheres. So if you see or hear someone waxing lyrical about ‘right brain’ this and ‘left brain’ that, chances are they probably don’t have any qualifications in neuroscience or psychology.

Apart from the passage of time, there is another key point to be made here. The research was based on people with epilepsy and who had their corpus callosum cut, therefore ending communication between the two brain hemispheres. This hardly sounds like a sample representative of the general population. It’s a pretty select group.

So what does up-to-date research have to say?

Contemporary evidence for the right-brain/left-brain theory

Inevitably there has been a wealth of research published on neuroscience since the 1960s. Unfortunately, much of this will not find its way into newspaper headlines of pop-psychology books.

In an attempt to better understand brain lateralization with a view to treating medical conditions (rather than myth-busting), scientists at the University of Utah in analysed more than 1000 brains to see if people had dominant sides. They found no evidence. On average, both sides of the brain were essentially equal. The study’s lead author, Jeff Anderson, explains that while it is true some brain functions occur in one side or the other (language: left; attention:right), ‘[P]eople don’t tend to have a stronger left- or right-sided brain network. It seems to be determined more connection by connection’.

The overall conclusion from this an other up-to-date research is that the two sides of the brain communicate through the corpus callosum to work together to perform a variety of tasks.

Why does the popularity of the right-brain/left-brain theory persist?

Searching online I found some interesting and amusing exchanges between the supporters of the right-brain/left-brain theory and its critics. In response to a discussion of up-to-date, peer-reviewed research from leading neuroscientists, the striking thing is that supporters of the theory offer personal anecdotes to ‘disprove’ the research. The subtext is, ‘that’s all very interesting but it doesn’t apply to me’. Here’s one example:

When I am studying math or chemistry intensely I find the left side of my brain hurts, Whereas when I am writing a report or something along the lines of literature, the right side of my brain hurts. It’s a nice pain though. I was not aware of this right brain left brain theory until I started noticing this happening and researched it for myself. Amazing really.

This inspired a particular pointed (cruel) response:

You should see a doctor. It’s not amazing, it sounds more like you’ve sustained a stroke.

In a follow-up comment, the same ‘wag’ makes another important point:

Wow, from some of the posts . . . you would think the world is full of neuroscientists that are all incapable of doing a simple internet search for information.

This last comment is quite telling, It highlights a phenomenon in social psychology, in particular the subject of stereotypes. A stereotype is a generalized, over-simplified packet of knowledge about something. We can see in the realms of prejudice where are a stereotype can act as a filter for new information. Anything that contradicts the stereotype is rejected. So, yes, all this neuroscience may be very interesting but if it contracts a strong belief in the right-brain/left-brain theory, then the scientists must have made errors. The results have to be rejected. The fact that the research went through a rigorous review process does not matter. At the same time the supporter of the right-brain/left-brain theory will overlook the lack of a generalized sample for Sperry’s research. By time the belief is firmly held, the whole question of research may not even matter anymore. ‘My head hurts on the left hand side when studying maths, that’s good enough for me’.

There is also the question of exposure to information. Magazines and reality TV pundits like to offer a ‘bit of science’. For the purpose the ‘science’ needs to be easy to comprehend. So idea of right-brain/left brain keeps popping up. The more a thing is repeated leads us to question whether ‘there must be something in it’.

How to interpret right-brain/left-brain tests

Common magazine pencil-and-paper test of right-brain/left-brain begin with the assumption that there is specialization. This is written into each of the questions in these tests. The results are foregone conclusions. Reducing human experience to a binary is always problematic. Nature never creates a dichotomy. That’s something we do to help explain thing. Black and white categories are easier to process. Rarely do these over simplifications map onto real-world experience. So at the very best, treat these tests as a bit of fun

A better strategy is to spend time taking stock of your own abilities and strengths. It’s easy to look for evidence to contradict the test’s verdict. Instead, balance things out and look for any evidence that contradicts the result. Think of your life experience. The longer you spend on this phase, the more evidence you will find to contradict the results and the more you will realize is what modern neuroscience tells us: you’re using both sides of your brain pretty much equally. What you will have is a better picture of yourself as resourceful, psychologically rounded human being.

That’s got to be a boost to your confidence and self-esteem. Much better than believing you’re living only half of the human experience.

Links

Interhemispheric Interaction During Global–Local Processing in Mathematically Gifted Adolescents, Average-Ability Youth, and College Students
An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging
Check out books by Dr Gary Wood and his recommendations on Amazon.co.uk and Amazon.com

The Dangers of Social Networking: Are We Frying Our Brains? Is it 21st Century Onanism?

Posted on 27 February, 2009 by Gary Wood

Social networking: Are we in danger of infantilization?

Internet social networking has now become the target for age old debate on harmful media influences. Leading neuroscientist Professor Susan Greenfield has speculated that as we spend too much time on sites such as Facebook and Twitter, we run the risk of infantalizing the mid-21st mind. However haven’t we heard similar arguments before most notably with TV and video games, right back to the chivalry books of Don Quixote? Indeed eerily similar warnings of the dangers of on-line social networking were also made for masturbation (onanism) in the 19th century. According to Lord Baden-Powell, such ‘beastliness’ was said to destroy both health and spirits so that the practitioner becomes ‘feeble in body and mind and often ends in a lunatic asylum’. Is social networking becoming the onanism of the 21st century?

Too much on-line onanism?

At best, Prof. Susan Greenfield’s comments are conjecture. She admits that there is no evidence to support her assertions (see Newsnight link below). So why bother then? Well, she’d just like the government to provide some funding to satisfy her hunch. But by contrast, oh the bells, the alarm bells from Dr Aric Sigman who claims that there is ample evidence although, according to Dr Ben Goldacre (Bad Science) Sigman only bothers to look at half of it (see link below). In short, the half that would provide us with a balanced scientific perspective is missing. It is worth pointing out that Dr Sigman’s piece does not cite any research that he carried out (although it’s difficult to tell as he did not cite the full list of authors in his reference list, so he may be in there somewhere). The paper looks to be a literature review with his own conclusions and he concedes (in the Newsnight interview) that it is meant to be a one-sided piece intended to provoke discussion, something he appears to specialize in (see: In Bed With Mary Whitehouse). The paper is based on the assumption that Internet social networking increases isolation and loneliness which in turn leads to health problems.

As with many of these media-scare stories, the more dramatic conclusions require a leap of faith that correlational studies indicate causation. They do not. So for instance, does Internet social networking increase isolation and loneliness or do lonely and isolated people seek out a means to make themselves less so? This could mean that on-line social networking is a positive thing. And perhaps we should for a moment consider e-learning’, providing wider educational opportunities? No, the ‘e’ doesn’t stand for evil!

Dr Sigman speaks of displacement arguing that children are sitting in front of a computer when they could be out socializing with friends. However, couldn’t the same argument be made for watching television (er, yes it has), reading and even doing homework. I know I would have rather been out playing ‘kick the can’ as a child, when I was stuck in doors reading about the printing press and how it gave ‘the great unwashed’ ideas above their station (pretty much in the same way as the Internet does today). Worries that children can be too ‘bookish’ are now largely overlooked in favour of newer ‘dangers’. And presumably, on-line social networking has displaced ‘staring aimlessly out of the window on a rainy day’ too.

Sigman has also made the claim that we can only be friends with someone if we can shake hands with them. That’s assuming that everyone has hands and that they can shake them! He also makes questions whether we should be chatting on-line to people across the globe instead of playing with ‘real friends’. Has he forgotten ‘penpals’ at school, the practice of writing to complete strangers in different countries? It was heartily encouraged! As a social psychologist, I would have thought connecting with people from other lands was a good thing (in contrast with good old-fashioned, small-minded, back-porch xenophobia). However, some evidence suggests young people are using online social networking primarily to enhance existing friendships and interaction with ‘e-friends’ is secondary. Unfortunately Facebook only uses th category ‘friends’ for all online contacts. It doesn’t mean that each and every is viewed the same; users may make their own distinctions. Thinking about my own experience. I have over 600 contacts in my email contact list although only 20 that I use frequently. It is not a coincidence that these are the people with whom I have the greatest face-to-face contact. In short, much of the headline-seeking, scare mongering stems from a failure to understand how the average user uses online social networking, instead indulging in worst case scenarios. I could go on but instead invite you to read Sigman’s article and with the aid of Goldacre’s response ask you to think of alternative explanations that make up the whole of the picture. And while you’re at it consider how Greenfield throws together a heap of ideas and assumptions that do not necessarily have to be connected in the same way as she does.

So are we all twittering ourselves into oblivion?

Much has been made of the ‘rewiring our brains’ hypothesis and Prof Greenfield has speculated that in middle of the 21st Century – that is in about 40 years time – our brains will be different. This seems a little premature to say the least. Sigman would warn us about exposing young brains to novel experienes but this also includes just about everything at school. Children have an enormous capacity for integrating new experiences. Chances are the world will be a different place and yes humans will adapt. Isn’t that learning? In the long-term isn’t it evolution?

We simply do not have the evidence to assess the extent of brain changes and it certainly won’t just be all down to how much time we spend chatting to our real or ‘virtual friends’. Life is so much more quixotic! It’s also important to recognise that new technologies impact on different people in different ways. The diffusion of any innovation is such that we have innovators, early adopters, the late majority with laggards, er . . lagging behind. So will we have a sliding scale of brain-mush? Will the ‘slow on the uptake’ be spared? Again, more conjecture. It’s simply not possible, nor scientific, to conclude that any changes will be for the worst and to pretend that ‘brain infantilization’ or ‘hairy-palmed isolation’ are foregone conclusions (or even likely) is at best bad science. It’s just another example of not letting the evidence get in the way of a good story.

See Links: