Mahjong and the Mind
A workout for the mind,
set at a table for four.
Research suggests that games like mahjong, played regularly and in good company, are a brain-healthy habit. Here is what the studies say, and why I teach the way I do.
From the instructor
It started in my twenties
In the late 1990s, in my late twenties, I was Director of IT at Brain.com, founded by Josh Reynolds, the entrepreneur behind the Mood Ring and the ThighMaster. My team moved cognitive games off floppy disks and onto the early web.
We built a 5-minute IQ test to introduce people to thinkFAST, and more than a million people took it. thinkFAST was ten brain-training exercises that timed every response to the millisecond. By the time the dot-com bust hit, Brain.com was logging roughly 450,000 visits a month, with players tracking their scores and working toward becoming Brain Masters.
Even then, we knew a mind isn’t meant to train alone. Our forums were full of players comparing notes, and Brain Masters earned a members-only forum of their own. After the bust, the company took those assessments into doctors’ offices, where versions of them are still used today.
Decades later, teaching mahjong, I found a game that works the same mental skills and offers what no forum could: real people across the table.
What the research says
Promising, consistent, and still early
Most of the research on mahjong comes from Hong Kong and mainland China, where the game is part of daily life for many older adults. The findings point the same way.
It helped people hold steady.
In a nine-month trial, nursing homes were randomly assigned to mahjong, tai chi, or simple handicrafts. Residents with mild dementia who played mahjong maintained their cognitive scores while the handicraft group declined.
Gains appeared quickly and lasted.
In a 16-week study of 62 older adults with dementia, mahjong players improved on every cognitive measure, and the gains held a month after play stopped.
Players had lower dementia risk over time.
A national study following older adults in China for up to ten years linked playing cards or mahjong with a lower risk of developing dementia.
It was linked to better mood.
Among nearly 11,000 adults 45 and older, regular mahjong was associated with fewer symptoms of depression for city residents.
What it does not say
These studies show links and short-term effects, not a cure. No one has shown that mahjong prevents Alzheimer’s disease. What the evidence supports is simpler: a busy mind and a full calendar of people are good for your brain, and mahjong offers both.
Four kinds of memory, one table
thinkFAST tested them one at a time. Mahjong asks for all four.
01
Immediate memory
Holding on to what just happened: the tile your neighbor discarded, the call made a moment ago. In the nine-month nursing home trial, mahjong players held steady on repeating back a string of numbers while the comparison group slipped.
02
Working memory
Holding information in mind while you use it. Rearranging your rack in your head, counting which tiles are still live, weighing two hands on the card at once.
03
Delayed memory
Recalling what you took in earlier: the hands on this year's card, the steps of the Charleston, what a player exposed ten turns ago. In the same trial, mahjong players held steady on recalling a word list after a delay.
04
Executive function
Sometimes called executive memory, it is the brain's project manager: choosing a hand, planning ahead, and pivoting when the Charleston surprises you. In a small 12-week trial, older adults with mild memory problems who played mahjong improved on executive function tests.
And underneath it all, speed. Spotting a call before the next player racks is processing speed, the skill thinkFAST measured in milliseconds. In the long-running ACTIVE trial, computer speed training was linked to 25% lower dementia incidence over 20 years. That study did not use mahjong, but a small Hong Kong study found longtime players had quicker reaction times than non-players.
These studies were small, mostly in older adults who already had memory concerns, and used Chinese mahjong. They suggest the game gives every kind of memory a regular workout. They do not show that it prevents memory loss.
Why the table matters
It is not only the tiles. It is the table.
The 2024 Lancet Commission on dementia listed social isolation in later life among 14 risk factors people can change. And in the University of Georgia study, the mood benefit of mahjong disappeared where the game tended to turn competitive or into gambling. The kind of table matters.
That is the table I set at Starlit: welcoming to beginners, generous with questions, and as much about the conversation as the hand.
The series
Read more
Part 1 · 5 min read
From floppy disks to the tile table
In my late twenties, I helped bring brain-training games to the early web. Here is what that taught me about memory, speed, and the need for people.
Part 2 · Arriving October 27, 2026
Mahjong and your brain: what the research really says
Four studies in plain language, with the honest caveats.
Part 3 · Arriving November 3, 2026
Four kinds of memory, one table
Immediate, working, delayed, and executive memory, plus processing speed, and where each shows up in a game.
Part 4 · Arriving November 10, 2026
Why the table matters as much as the tiles
Social connection, brain health, and how Open Play is designed around both.
Part 5 · Arriving November 17, 2026
Your brain at the table: a beginner's guide
What to expect at your first class or Open Play, and why learning something new is the point.
Sources
- Cheng et al., American Journal of Geriatric Psychiatry, 2014Cluster-randomized trial in nursing homes. Mahjong players held steady on overall cognition, delayed recall of a word list, and forward digit span while a handicraft group declined, ending 4.5 MMSE points higher at nine months.
- Cheng et al., International Journal of Geriatric Psychiatry, 200662 older adults with mild to moderate dementia played for 16 weeks. Gains on every cognitive measure, still present a month after play stopped.
- Zhang et al., Frontiers in Neurology, 2020Pilot randomized trial, 56 older adults with mild cognitive impairment. Mahjong three times a week for 12 weeks improved executive function scores; the control group did not change, though the gap between groups was not statistically significant.
- Chinese Longitudinal Healthy Longevity Survey analysis, 2022Older adults followed for up to ten years. Playing cards or mahjong was associated with a lower risk of dementia.
- Chen et al., University of Georgia, Social Science & Medicine, 2019Nearly 11,000 adults 45 and older. Regular mahjong was linked to fewer depressive symptoms for city residents, with no link where play tended to be competitive.
- ACTIVE trial 20-year follow-up, Alzheimer's & Dementia: TRCI, 2026Randomized trial of 2,832 older adults. Computer speed-of-processing training with booster sessions was linked to 25% lower dementia incidence over 20 years.
- Tsang, Wong & Gao, Journal of Physical Therapy Science, 201641 adults 60 and older. Longtime mahjong players had shorter reaction times than non-players. A snapshot study, so it cannot show cause and effect.
- Livingston et al., Lancet Commission on Dementia, 2024Social isolation in later life is one of 14 modifiable risk factors for dementia.
This page shares general information about research on leisure activities and brain health. It is not medical advice. If you have concerns about memory or thinking, please talk with your doctor.
Come to the table
The best brain workout I know is a seat at the table.
Already learned
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