Am I left-brained or right-brained?
Neither, and nobody else is either. When Jared Nielsen and colleagues analysed resting brain scans of 1,011 people aged 7 to 29 in 2013, they found networks that lean to one side, but no people whose whole brain leaned left or right. Yet in a 2017 US survey, 64% of 3,045 adults agreed that some people are left-brained and some right-brained.
This left brain right brain test plays it both ways. Five questions in the style of the popular online quizzes hand you a percentage, and then the page shows why it means nothing. Then it measures a left–right bias that is real, with the chimeric faces task Jerre Levy and colleagues described in 1983: two mirror-image copies of a face, each smiling on only one half, and you pick the one that looks happier, ten times. Your picks become a laterality quotient, the score the studies use, compared with 348 right-handed adults from Nguyen and Laycock’s 2025 study.
It is not a brain scan, a personality test or an IQ test. Ten faces give a rough score, so the result also shows how often coin flips alone would give a split as lopsided as yours.
What the test measures
One thing: which half of a face you rely on when you read its expression — not which half of your brain you are.
The task
- Five quiz questions in the popular left brain / right brain style, scored their way, then taken apart
- One question about your writing hand, used only to explain your result
- The chimeric faces task (Levy, Heller, Banich & Burton 1983): 10 pairs, one face above the other; pick the happier one
- Photographs of 10 real volunteers, women and men of different ages and backgrounds, from the Face Research Lab London Set (CC BY 4.0)
- The left-smiling copy is on top in half the pairs, so a habit of picking the top cancels out; after each pick you see only “Noted”
Your result
- How many of the 10 times you picked the face smiling on your left, and your laterality quotient
- Your place among right-handed adults (Nguyen & Laycock 2025), with reference points from Coronel & Federmeier (2014) and Gupta & Pandey (2010)
- A coin-flip check, what your writing hand says about language (Knecht et al. 2000), and where the myth came from
- A shareable card and a link that challenges a friend to the same ten faces
Before you start
- About a minute and a half on a phone or a computer, in a browser with 3D graphics (WebGL). Free, no sign-up; a challenge link keeps your name, score and picks after the # in the address, which browsers don’t send to the server
Left brain, right brain FAQ
Is this test free? Do I need to sign up to see my result?
Yes, it’s free, and there’s nothing to sign up for: no account, no email, no payment. Your result appears on this page the moment you finish, and you can share it or play again straight away.
Is the left brain right brain theory true?
No, not as a personality type. The two hemispheres do specialise: in most people language relies mainly on the left hemisphere. But in Nielsen et al.’s 2013 analysis of 1,011 resting brain scans, people with strongly lateralised left-side networks did not have weaker right-side ones. Lateralisation belongs to particular networks, not to people.
Where did the left brain right brain idea come from?
From real research, simplified. In the 1960s Roger Sperry and colleagues showed in split-brain patients that the two hemispheres specialise, and Sperry shared the 1981 Nobel Prize in Physiology or Medicine. On the way to the self-help shelf, “some tasks lean on one side” became “some people are one side”.
What is the chimeric faces test?
The chimeric faces test shows two versions of the same face, one smiling on its left half and one on its right, and asks which looks happier. The two are mirror images, so a steady preference has to come from you, not from the faces. Jerre Levy and colleagues described the free-viewing version in 1983 and found each person’s lean reliable and stable. Which way most people lean, and why, is on the result sheet.
What is a normal score on the chimeric faces test?
The left brain right brain test shows the typical score on your result sheet, after your ten picks, because knowing it first could steer them. The comparison comes from Nguyen and Laycock’s 2025 study of 348 right-handed adults, whose scores spread widely, so plenty of people land near zero.
Does being left-handed change which side of the brain I use?
It changes the odds for language, not your personality. In Knecht et al.’s 2000 study of 326 healthy adults, language ran mainly in the right hemisphere in 4% of strong right-handers, 15% of people with no strong preference and 27% of strong left-handers. The comparison curve here is right-handers only.
Are the faces real people?
Yes: ten volunteers from the Face Research Lab London Set, published by Lisa DeBruine and Benedict Jones in 2017 under CC BY 4.0. Each was photographed with a neutral face and with a smile and consented to the photos being used, original or altered, in web-based studies. Each pair joins half of the smiling photo to half of the neutral one, plus its mirror image.
Why did I get a different result the second time?
Ten faces is a small sample: the same person’s score can move by around ±0.3 between runs, and only 9 or 10 of 10 one way is clearly more than luck. A lean that shows up in two or three runs is more likely to be your own.
Where the numbers come from
Your rank compares your score with a normal curve built from the mean and standard deviation of the 348 right-handed adults in Nguyen & Laycock (2025), widened for 10 trials instead of their 48; their raw data were not available. The other chimeric-face studies are shown as reference points, not ranked against. The site does not publish its own players’ data.
- Nielsen, Zielinski, Ferguson, Lainhart & Anderson (2013), PLOS ONE — An evaluation of the left-brain vs. right-brain hypothesis with resting state functional connectivity magnetic resonance imaging
- Levy, Heller, Banich & Burton (1983), Brain and Cognition — Asymmetry of perception in free viewing of chimeric faces
- Nguyen & Laycock (2025), Cognitive, Affective, & Behavioral Neuroscience — Right-hemisphere lateralisation evidenced from the chimeric face task predicts self-reported social competencies
- Coronel & Federmeier (2014), Frontiers in Psychology — Task demands modulate decision and eye movement responses in the chimeric face test
- Gupta & Pandey (2010), Industrial Psychiatry Journal — Assessment of hemispheric asymmetry: development and psychometric evaluation of a chimeric face test
- Knecht et al. (2000), Brain — Handedness and hemispheric language dominance in healthy humans
- Macdonald, Germine, Anderson, Christodoulou & McGrath (2017), Frontiers in Psychology — Dispelling the myth: training in education or neuroscience decreases but does not eliminate beliefs in neuromyths
- Dekker, Lee, Howard-Jones & Jolles (2012), Frontiers in Psychology — Neuromyths in education: prevalence and predictors of misconceptions among teachers
- The Nobel Prize in Physiology or Medicine 1981 (Roger W. Sperry, David H. Hubel, Torsten N. Wiesel)
- DeBruine & Jones (2017), figshare — Face Research Lab London Set (CC BY 4.0): the photographs used for the chimeric faces
How the score works
Laterality quotient (LQ)
(right-smile picks − left-smile picks) ÷ trials, from −1 (always the smile on your left) to +1 (always the smile on your right). The cited studies use the same formula; Gupta & Pandey scale it to −100…100.
Comparison curve
A normal curve from the mean and standard deviation of Nguyen & Laycock’s 348 right-handed adults, widened for 10 faces instead of 48; both numbers are on the result sheet. Their raw data weren’t available, so it is an approximation, for right-handers only.
Coin-flip check
The two-sided chance that 10 random picks would split at least as unevenly as yours.