Left Brain / Right Brain Bunk?

Willingham: Left/right brain theory is bunk


By Daniel Willingham
Washington Post

An article was published this week in the venerable (and reliable) psychology journal Psychological Bulletin, which synthesized 67 brain imaging studies of creativity. Among other things, it showed that creativity is not especially a right-brain function. In fact, two of three broad classes of creative thought that have been studied seem not to depend on a single set of brain structures.

What we call “creativity” is so diverse that it can’t be localized in the brain very well.

One might think that this study would put to rest at least part of the left brain/right brain mythology, namely, that the right hemisphere of the brain is more responsible for creative thought than the left.

One would think so, but I wouldn’t count on it.

In the usual mythology, the left hemisphere of the brain is logical, ordered, and analytic, and it supports reading, speech, math, and reasoning. The right hemisphere is more oriented towards feelings and emotions, spatial perception, and the arts, and is said to be more creative.

We have known for at least 30 years that this characterization is incorrect.

The language we find useful to discuss mental functions is, for the neuroscientist, a rather high level of description. That is, for a function like “reading” or “music” much of the brain gets into the act. Each is not supported by a single hemisphere.

For example, even a seemingly simple function like “learning a sequence” depends on numerous brain areas. In this brain imaging study some colleagues and I found that 14 brain areas contribute to the sequencing task we examined. “Sequential thought” is supposed to be a left brain function, but we observed five areas in the left hemisphere, five in the right, and four bilateral. (That is, the activity was in corresponding areas of both the left and right hemispheres.)

This doesn’t mean that the two hemispheres of the brain don’t sometimes (or often) do different things. It means that the language we find useful in talking about thinking is too coarse to capture these differences.

I say “sequencing” and that corresponds to 14 different brain areas! So thinking that we can identify an array of these tasks--logical thinking, language, math, and others--that all depend mostly on one hemisphere seems a little far-fetched. More to the point, we know it’s inaccurate.

Okay, inaccurate. But harmful?

Not always. Sometimes I hear hear the terms “left-brain thinkers” or “right brain thinkers” as a shorthand to describe people who are drawn to more logical, ordered ways of thinking, in contrast to more “artsy” types. It’s understood that there is not meant to be any scientific weight to the labels. They are just a convenience.

An astronomer may use the term “sunrise” without worrying that he’s being a bad scientist because he knows that the sun doesn’t really rise over the earth. It’s understood to be a figure of speech.

Unfortunately, left brain/right brain is sometimes taken more seriously.

This idea is used in education in two ways. Sometimes the left brain/right brain distinction is offered as an account of differences in ability, much as in the casual (and harmless) way I described.

But when offered as a more scientifically weighty theory, people start to call for school to be more right brain oriented.

Sometimes this call is pitched in terms of fairness; the right-brain kids seem to be at unfair disadvantage. Sometimes it’s pitched as common sense; we’re ignoring half of kid’s brains!

Other people treat the left brain/right brain distinction not as a distinction of abiity (what kids are good at) but as a learning style (how kids prefer to learn). Left-brain kids will understand a concept best by talking about it, for example, but right brain kids will want to draw a diagram.

Teachers might be urged to engage in whole-brain teaching by including different ways of understanding a concept that honor left brain and right brain differences.

In both cases, prescriptions are given greater weight because of the apparent neuroscientific basis of the recommendations. “Kids who have trouble with reading, math and science are at a disadvantage at school,” sounds obvious and unimpressive when compared to “right brain dominant children are at a disadvantage at school.”

But if the distinction as usually described is inaccurate, there is no scientific weight behind the prescriptions.

Still, I’m not counting on the latest article on creativity to quell enthusiasm for inaccurate left brain/right brain science.

Mike Gazzaniga, one of the pioneers of the modern study of brain hemispheric differences, tried to put a damper on the craziness in a book chapter titled “Left brain, right brain: A debunking.”

That was 25 years ago and there is still plenty of bunk.