People and chance
Why everyone picks 7
Think of a number between 1 and 10. Got one? There’s a decent chance it was 7. Here’s why humans are such predictable randomisers — and why that matters.
Skip to the experimentTry a small experiment at your next dinner. Ask everyone to think of a number between 1 and 10 and write it down. Then ask for a show of hands: who wrote 7?
If the table is anything like the people psychologists have been quietly polling for fifty years, far more hands go up than the one-in-ten you would expect. Ones, twos and tens barely appear. Five feels “too middle”. Seven feels just random enough.
That little tell is the whole story of this page. We are not very good at being random — and we are not random in a very consistent way.
Three sevens would not be unusual.
Your turn. Pick a number, and we’ll show you how your choice compares with everyone else’s — and with a machine that genuinely doesn’t care.
Pick a digit from 0 to 9.
Tap the first one that comes to mind — the same question the 1976 study asked.
Pick a number to begin. Your choice stays in your browser.
The people figure is the 28.4% reported by Kubovy and Psotka (1976) for the digit 7; we don’t collect readers’ picks. The generator chart is drawn fresh, on your device, each time.
Seven, by a mile.
Psychologists have run the dinner-table experiment properly. In 1976 Michael Kubovy and Joseph Psotka asked people for the first digit that came to mind, 0 to 9. If choices were even, each digit would get 10%. Seven got 28.4% — nearly three times its share.
The interesting part is how easily the spell breaks. Ask for a number between 6 and 15 instead, and 7’s share drops to 17.3%. Mention 7 as an example before asking, and it drops to 16.6%. We don’t love 7 for itself; we love it because it feels like the number nobody else would say. Odd, prime, not in the middle, not at an edge. The moment it feels suggested, it stops feeling random.
There is even a colour attached. Ask for a number and a colour and the most common pair, in studies from 1971 and 1972, was 7 and blue — the “blue-seven phenomenon”.
Bigger ranges, same habit.
Make the range 1 to 20 and the favourite becomes 17 — in an informal online poll of 347 readers in 2007, roughly one in six said it. Make it 1 to 100 and things get stranger. In 2024 the YouTube channel Veritasium asked about 200,000 viewers for a random number; setting aside the extremes and the joke answers 42 and 69, the standouts were 7, 73, 77 and 37, and when people were asked which number the fewest others would pick, 73 and 37 tied for the lead. Everyone trying to be unpredictable, all in the same direction.
It isn’t only numbers. Asked to write down a random string of heads and tails, people switch sides about 60% of the time where a real coin switches 50%, and they judge the over-switching sequences as the most random ones. We have a picture of randomness in our heads, and the picture is too tidy.
Even the machines that learned from us do it
Large language models are trained on human text, and they inherit the habit. In a 2025 study of 75,600 requests, several models asked for a number from 1 to 10 answered 7 about 80% of the time. In June 2025 four different chatbots, asked to guess a number from 1 to 50, all said 27. Model behaviour shifts with every version — the figures above are tied to their dates — but the lesson holds: an imitation of a person is not a random number generator either.
Why this matters more than a party trick.
If you need a number for a prize draw, a seating plan or a classroom pick, “I’ll just think of one” is the worst available method. You will drift towards the middle, avoid repeats, dodge the numbers you used yesterday, and if you are a teacher you will somehow never land on the student in the corner. None of that is malice. It is simply that a person has favourites and a good generator does not.
That is what the second half of the experiment above shows. A thousand picks from our generator spread out flat: every number near 10%, no 7-shaped bump, no gaps. Boring, in exactly the way you want.
So the next time someone says “pick a number, any number” — enjoy saying 7. Then reach for something that genuinely doesn’t care.
Let something that doesn’t have a favourite choose.
A number from 1 to 10 with no feelings about 7 whatsoever.
Pick a number from 1 to 10Where we looked things up
- The predominance of seven and the apparent spontaneity of numerical choices — Kubovy & Psotka, J. Exp. Psych.: HPP 1976 (record)
- Number and Color Responses of Some College Students — Simon, Perceptual and Motor Skills 1971 (record)
- Randomness wrap-up — Cognitive Daily, ScienceBlogs 2007
- Why is this number everywhere? — Veritasium, YouTube, 2024 (figures as stated in the video)
- Making sense of randomness — Falk & Konold, Psychological Review 1997 (PDF)
- Deterministic or probabilistic? The psychology of LLMs as random number generators — arXiv 2025
- Ask a model to guess a number from 1 to 50 and it’s likely to answer 27 — The Register, 2025