Myths and famous claims
Left brain vs right brain: is it real?
What is documented
People are not left-brained or right-brained. A 2013 study of resting-state brain scans from 1,011 people aged 7 to 29 found no support for global left-brain or right-brain dominance. Lateralization is real, but it is a local property of particular brain networks, not a trait of the whole person.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
The myth
The idea is that each person is dominated by one half of the brain. "Left-brained" people are supposed to be logical, verbal and analytical; "right-brained" people creative, intuitive and visual.
The short verdict
The brain's two halves do specialize in some functions, but people do not sort into left-brained and right-brained types. The best direct test of the idea found no support for it.
What the evidence shows
A 2013 study in PLOS ONE analyzed resting-state brain scans of 1,011 people aged 7 to 29 to test whether some people are left-brain or right-brain dominant (Nielsen et al. 2013). If the popular idea were right, some people should show stronger networks across the whole left side, and others across the whole right side. That is not what the data showed. The study found that lateralization is a local property of brain networks, and that the data do not support "left-brained" or "right-brained" people (Nielsen et al., 2013).
In plain terms: a given network may lean on one hemisphere, but a person who has one strongly lateralized network is not more lateralized across the board. The labels describe parts of brains, not kinds of people.
Try one · Spatial Reasoning
Which option is the same shape, only rotated?
Tap the option you think is right, or show the answer.
Show the answer
Option 4 is the original figure turned a quarter turn counterclockwise.
How to solve it
- Pick a landmark: the marked cell or the end of the longest arm.
- Turn the figure in your head and watch where that landmark goes, and which side the other cells end up on.
- Turning the figure a quarter turn counterclockwise gives option 4.
- Each of the other options is a mirror image: flipping it over would match, but no turn does.
That was 1 puzzle. The full test has 25.
Where it came from
The popular version takes something real, that some brain functions lean on one hemisphere, and stretches it into a personality type. The sources we rely on do not document exactly how that stretch happened, so we will not guess at its path. What they do document is that the stretched version fails when tested directly.
Why it persists
It is easy to believe and pleasant to apply. In a 2012 survey of 242 UK and Dutch teachers interested in neuroscience, 91% of the UK teachers and 86% of the Dutch teachers endorsed the left-brain and right-brain idea (Dekker et al., 2012). The same survey found that teachers with more general knowledge about the brain were more likely to believe neuromyths. A neat two-type story is memorable in a way the real findings are not.
How to spot a brain-type claim
- Does it sort whole people into types, rather than describe particular brain networks?
- Does it cite a brain-imaging study that tested the sorting directly?
- Does it promise better learning or work if you act on your type, and is there a study showing that?
What is actually true
- Some brain networks are lateralized, and that specialization is local to those networks.
- Intelligence relies on networks spread across both hemispheres. Jung and Haier's review of 37 imaging studies proposed a network linking frontal and parietal regions with parts of the temporal and occipital lobes (Jung & Haier, 2007).
- Sorting learners into types for teaching has a poor record more generally: a major review found virtually no evidence that matching instruction to a preferred learning style helps (Pashler et al., 2008).
Read more on brain and intelligence, the closely related learning styles myth and the claim that we use only 10% of our brain. If you are curious about the kinds of reasoning IQ tests sample, try the spatial reasoning practice test.
Sources
- Nielsen, J. A., Zielinski, B. A., Ferguson, M. A., Lainhart, J. E., & Anderson, J. S. (2013). An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging. PLOS ONE, 8(8), e71275. doi:10.1371/journal.pone.0071275 journals.plos.org/plosone/article?id=10.1371/journal.pone.0071275
- Nielsen, J. A., Zielinski, B. A., Ferguson, M. A., Lainhart, J. E., & Anderson, J. S. (2013). An evaluation of the left-brain vs. right-brain hypothesis with resting state functional connectivity magnetic resonance imaging. PLOS ONE, 8(8), e71275. doi.org/10.1371/journal.pone.0071275
- Dekker, S., Lee, N. C., Howard-Jones, P., & Jolles, J. (2012). Neuromyths in education: Prevalence and predictors of misconceptions among teachers. Frontiers in Psychology, 3, 429. doi.org/10.3389/fpsyg.2012.00429
- Jung, R. E., & Haier, R. J. (2007). The Parieto-Frontal Integration Theory (P-FIT) of intelligence: Converging neuroimaging evidence. Behavioral and Brain Sciences, 30(2), 135-154. doi.org/10.1017/S0140525X07001185
- Pashler, H., McDaniel, M., Rohrer, D., & Bjork, R. (2008). Learning styles: Concepts and evidence. Psychological Science in the Public Interest, 9(3), 105-119. doi.org/10.1111/j.1539-6053.2009.01038.x